Chapter 8: Genetic Assessment and Counseling
During inspection, pay particular attention to certain
-body areas, such as the space between the eyes; the height, contour, and shape of ears; the number of fingers and toes; and the presence of webbing because these often suggest structural genetic disorders.
REPRODUCTIVE ALTERNATIVES Some couples are reluctant to seek genetic counseling because they are afraid they will be told it would be unwise to have children. Helping them to realize viable alternatives for having a family exist can allow them to seek the help they need. What are some alternatives ?
1.Alternative insemination by donor (AID) is an option for couples if the genetic disorder is one inherited by the male partner or is a recessively inherited disorder carried by both partners. AID is available in all major communities and can permit the couple to experience the satisfaction and enjoyment of a usual pregnancy 2.If the inherited problem is one arising from the female partner, surrogate embryo transfer is an assisted reproductive technique that is a possibility. For this, an oocyte is donated by a friend or relative or provided by an anonymous donor, which is then fertilized by the male partner's sperm in the laboratory and implanted into a woman's uterus. -Like AID, donor embryo transfer offers the couple a chance to experience a usual pregnancy. 3.Use of a surrogate mother (a woman who agrees to be alternately inseminated, typically by the male partner's sperm, and bear a child for the couple) is yet another possibility 4.Adoption is an alternative many couples can also find rewarding . Lastly, choosing to remain child free should not be discounted as a viable option
THE ASSESSMENT FOR GENETIC DISORDERS History
1.obtain information and document diseases in family members for a minimum of three generations because a history can be a chief tool in discovering transmitted disorders -include half brothers and sisters or anyone related in any way as family. 2.Document the mother's age because some disorders increase in incidence with age. Document also whether the parents are consanguineous or related to each other. 3.Documenting the family's ethnic background can reveal risks for certain disorders that occur more commonly in some ethnic groups than others. -If the couple seeking counseling is unfamiliar with their family history, ask them to talk to senior family members about other relatives (grandparents, aunts, uncles) before they come for an interview about such instances as spontaneous miscarriage or children in the family who died at birth. In many instances, these children died of unknown chromosomal disorders or were miscarried because of 1 of the 70 or more known chromosomal disorders inconsistent with life. 4.Attempt to obtain as much information as you can by asking the couple to describe the appearance or activities of the affected individual ("She had no left side to her heart") or asking for permission to obtain health records. 5.An extensive prenatal history of any affected person should be obtained to determine whether environmental conditions could account for the condition
In Down syndrome, the person has an extra chromosome 21, so this is abbreviated as
47XX21 + or 47XY21 +
Even if a couple decides not to have more children, be certain they know genetic counseling is available for them should their decision change. Also be certain they are aware that as their children reach reproductive age, they too may benefit from genetic counseling. Couples who are most apt to benefit from a referral for genetic testing or counseling include:
A couple who has a child with a congenital disorder or an inborn error of metabolism. Many congenital disorders occur because of teratogenic invasion during pregnancy that has gone unrecognized. Learning the disorder occurred by a chance occurrence rather than inheritance is important because the couple will not have to spend the remainder of their childbearing years concerned another child may be born with the disorder (although a chance circumstance could occur again). If a definite teratogenic agent, such as a drug a woman took during pregnancy, can be identified, the couple can be advised about preventing this occurrence in a future pregnancy. A couple whose close relatives have a child with a genetic disorder such as a chromosomal disorder or an inborn error of metabolism. It is difficult to predict the expected occurrence of many "familial" or multifactorial disorders because they may involve more than one abnormal gene. In these instances, counseling should include educating the couple about the disorder, treatment available, and the prognosis or outcome of the disorder. Based on this information, the couple can make an informed reproductive choice about children. Any individual who is a known carrier of a chromosomal disorder. Understanding his or her own chromosome structure and the process by which future children could be affected can help such individuals make an informed choice about reproduction and also alert the person to the importance of fetal karyotyping during any future pregnancy. .Any individual who has an inborn error of metabolism or chromosomal disorder. Any person with a disease should know the inheritance pattern of the disease and should be aware if prenatal diagnosis is possible for his or her particular disorder. A consanguineous (closely related) couple. The more closely related two people are, the more genes they have in common, so the more likely it is that a recessively inherited disease will be expressed. A brother and sister, for example, have about 50% of their genes in common; first cousins have about 12% of their genes in common. Any woman older than 35 years of age and any man older than 55 years of age. This is directly related to the association between advanced parental age and the occurrence of Down syndrome. Couples of ethnic backgrounds in which specific illnesses are known to occur. Mediterranean people, for example, have a high incidence of thalassemia, a blood disorder; those with a Chinese ancestry have a high incidence of glucose-6-phosphate dehydrogenase (G6PD) deficiency, a blood disorder where destruction of red cells can occur
Common Chromosomal Disorders Resulting in Physical or Cognitive Developmental Disorders
A number of chromosomal disorders are easily detected at birth on physical examination. Many of these disorders leave children cognitively challenged
Some genetic disorders are so severe that fetal growth
cannot continue past that point. This early cell division is so precarious, in fact, that up to 50% of first trimester spontaneous miscarriages may occur as the result of chromosomal disorders
A nurse is interviewing a couple who has come for a preconception visit. The couple asks the nurse about inheritance and how it occurs, When describing the concept of genes and inheritance, the nurse explains that a gene that is expressed when paired with another gene for the same trait is called: A) dominant. B) recessive. C) homozygous. D) heterozygous.
Ans: A Client Needs: Health Promotion and Maintenance Cognitive Level: Apply Page: 158 Feedback: A dominant gene is one that will be expressed when paired with a like gene. Many genes are dominant in their action over others. When dominant genes are paired with nondominant (recessive) ones, the dominant genes are always expressed in preference to the recessive genes (a gene for brown eyes, for example, is dominant over one for blue eyes; a child born with a gene for brown eyes and a recessive one for blue eyes will have brown eyes).
A woman who has a recessive gene for sickle cell anemia marries a man who also has a recessive gene for sickle cell anemia. Their first child is born with sickle cell anemia. The chance that their second child will develop this disease is: A) 1 in 4. B) 2 in 4. C) 3 in 4. D) 0 in 4.
Ans: A Client Needs: Health Promotion and Maintenance Cognitive Level: Apply Page: 158 Feedback: Autosomal recessive inherited diseases occur at a 1-in-4 incidence in offspring. The possibility of a chance happening does not change for a second pregnancy.
When assessing newborns for chromosomal disorders, which assessment would be most suggestive of a problem? A) low-set ears B) slanting of the palpebral fissure C) short neck D) bowed legs
Ans: A Client Needs: Physiological Integrity: Reduction of Risk Potential Cognitive Level: Understand Page: 163 Feedback: A number of common chromosomal disorders, such as trisomies, include low-set ears.
The results of a pregnant patient's quadruple screen were positive, and an amniocentesis was performed. The amniocentesis report states no genetic anomalies present. What should the nurse do to assist this patient understand the test results? A) Reassure that the report of the amniocentesis is valid. B) Suggest that additional testing be performed on the fetus. C) Explain that most of quadruple screens are falsely positive. D) Remind that 30% of amniocentesis screens are falsely positive.
Ans: A Client Needs: Psychosocial Integrity Client Needs 2: Safe, Effective Care Environment: Management of Care Cognitive Level: Apply Page: 159 Feedback: Receiving a false-positive report is unfortunate because it can potentially interfere with the mother's bonding with her infant. Women may need some "debriefing" time after false-positive reports and may need to be reassured several times that the report of a possible chromosomal deviation was not true. The patient does not need additional testing done on the fetus. It is documented that 30% of quadruple screens are falsely positive. It is not true that 30% of amniocentesis screens are falsely positive.
What should the nurse include when counseling potential parents about genetic disorders? A) Environmental influences may affect multifactorial inheritance. B) Genetic disorders primarily follow Mendelian laws of inheritance. C) All genetic disorders involve a similar number of abnormal chromosomes. D) The absence of genetic disorders in both families eliminates the possibility of having a child with a genetic disorder.
Ans: A Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Health Promotion and Maintenance Cognitive Level: Apply Page: 159 Feedback: Not all genetic disorders follow Mendelian laws of inheritance. Diseases caused by multiple factors do not follow Mendelian laws because more than a single gene or HLA is involved. Environmental influences may be instrumental in determining whether the disorder is expressed. All genetic disorders do not involve a similar number of abnormal chromosomes. A family history may reveal no set pattern so an absence of genetic disorders in both families does not necessarily eliminate the possibility of having a child with a genetic disorder.
The nurse is beginning an assessment to determine a couple's chances of having offspring with genetic anomalies. What should the nurse include in this assessment? (Select all that apply.) A) Age of the female member of the couple B) Diseases in the family that span three generations C) Ethnic background of both members of the couple D) Minimal expression of a previously undiagnosed disorder E) Employment status of the male member of the couple
Ans: A, B, C, D Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Health Promotion and Maintenance Cognitive Level: Apply Page: 155 Feedback: When conducting a health history assessment in anticipation of genetic counseling, the nurse will assess the age of the female member of the couple because some genetic anomalies are more common in older female patients. The nurse will also assess the couple for diseases that span three generations in both of the families and will assess the couple's individual ethnic backgrounds. Physical assessment can identify minimal expression of a disorder that has gone previously undiagnosed. Employment status is not typically a part of the health history in preparation for genetic counseling.
A patient becomes concerned upon learning for the need to have a karyotype performed. What should the nurse explain to this patient about this test? (Select all that apply.) A) It photographs and displays chromosomes. B) It is procedure done on all pregnant women. C) It reveals diseases present on chromosomes. D) It can only be done during the first trimester of pregnancy. E) It guarantees that a fetus will not be ill from a genetic disorder.
Ans: A, C Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Health Promotion and Maintenance Cognitive Level: Apply Page: 155 Feedback: A karyotype photographs and displays chromosomes and is done to reveal diseases on chromosomes only. A karyotype is not performed on all pregnant women, but only those in which a genetic anomaly is suspected. The karyotype can be performed at any time during gestation and does not guarantee that a fetus will not be ill from a genetic disorder.
After an assessment, a couple planning marriage decides to schedule an appointment for genetic counseling in several months. Which information from the assessment would support this couple's decision? (Select all that apply.) A) The male and female are second cousins. B) The male has a friend who has hemophilia. C) The female has a foster brother with sickle-cell anemia. D) The male and female are both of Mediterranean descent. E) The female's sister gave birth to a baby with Down syndrome.
Ans: A, D, E Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Health Promotion and Maintenance Cognitive Level: Analyze Page: 159 Feedback: Couples who are most apt to benefit from a referral for genetic testing or counseling include a closely related couple, are of ethnic backgrounds in which specific illnesses are known to occur, and those whose close relatives have a child with a genetic disorder. Having a friend with hemophilia and a foster brother with sickle-cell anemia would not support the couple's decision to have genetic counseling.
The nurse prepares a couple to have a karyotype performed. What describes a karyotype? A) a blood test that will reveal an individual's homozygous tendencies B) a visual presentation of the chromosome pattern of an individual C) the gene carried on the X or Y chromosome D) the dominant gene that will exert influence over a correspondingly located recessive gene
Ans: B Client Needs: Health Promotion and Maintenance Cognitive Level: Remember Page: 155 Feedback: A karyotype is a photograph of a person's chromosomes aligned in order.
A number of inherited diseases can be detected in utero by amniocentesis. Which disease can be detected by this method? A) diabetes mellitus B) trisomy 21 C) phenylketonuria D) impetigo
Ans: B Client Needs: Health Promotion and Maintenance Cognitive Level: Remember Page: 165 Feedback: Karyotyping for chromosomal defects can be carried out using amniocentesis.
A nurse is providing care to a couple with an infant who was born with a congenital condition. When working with these parents, which information would be most appropriate to provide? A) the majority of congenital disorders are inherited. B) experiences the mother had during pregnancy are probably unrelated. C) it is likely that the mother drank alcohol during early cell division. D) the disorder has probably occurred in the family before.
Ans: B Client Needs: Physiological Integrity: Physiological Adaptation Cognitive Level: Apply Page: 159 Feedback: Many congenital disorders occur because of teratogenic invasion during pregnancy that has gone unrecognized. Learning the disorder occurred by a chance occurrence rather than inheritance is important because the couple will not have to spend the remainder of their childbearing years concerned another child may be born with the disorder As genetic disorders occur at the moment of conception, events during pregnancy occur after the problem is already present.
When counseling potential parents about genetic disorders, which statement would be appropriate? A) Genetic disorders primarily follow Mendelian laws of inheritance. B) Environmental influences may affect multifactorial inheritance. C) All genetic disorders involve a similar number of abnormal chromosomes. D) The absence of genetic disorders in both families eliminates the possibility of having a child with a genetic disorder.
Ans: B Client Needs: Psychosocial Integrity Cognitive Level: Apply Page: 159 Feedback: It is difficult to predict with certainty the incidence of genetic disorders because in some disorders, more than one gene is involved and environmental insults may play a role (cleft palate, for example).
A young married woman says that she is planning a tubal ligation because mental retardation runs in her husband's family and she does not want any children with this problem. Which nursing diagnosis would best apply to this couple? A) Anxiety related to marital issues B) Deficient knowledge of genetically inherited disorders C) Spiritual distress related to inappropriate approach to the issue of having children D) Sexual dysfunction related to the possibility of having a cognitively impaired child
Ans: B Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Health Promotion and Maintenance Cognitive Level: Analyze Page: 156 Feedback: The young woman is making a decision to not have children without having information about her husband's family and the people who have mental retardation. This is a knowledge deficit and is the most appropriate diagnosis for this couple. This situation does not support the diagnoses of anxiety, spiritual distress, or sexual dysfunction.
The nurse is visiting a family who has a child with a genetic disorder. The oldest daughter in the family is planning marriage within the next few months. Which intervention should the nurse include that would support the 2020 National Health Goals for genetic disease? A) Counsel the daughter to have no children. B) Encourage the daughter to have genetic counseling. C) Discuss voluntary sterilization options prior to marriage. D) Explain that the chance of genetic anomalies in children is slim.
Ans: B Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Health Promotion and Maintenance Cognitive Level: Apply Page: 155 Feedback: To support the 2020 National Health Goals for genetic anomalies, the nurses can help achieve these goals by being sensitive to the need for and educating parents about genetic screening in preconceptual settings. This means that the nurse should encourage the daughter to have genetic counseling. It is outside of the nurse's scope of practice to counsel the daughter to remain childless or undergo voluntary sterilization. The nurse would not know the daughter's chances of having a child with a genetic disorder unless genetic testing is performed.
A child is diagnosed with an X-linked dominant inheritance disorder. What should the nurse explain to the parents about this disorder? A) It only affects male offspring. B) It appears in every generation. C) All children of the couple will be affected. D) Diseases caused by this disorder are not life threatening.
Ans: B Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Physiological Integrity: Reduction of Risk Potential Cognitive Level: Apply Page: 162 Feedback: X-linked dominant inheritance disorders appear in every generation. The pattern of inheritance is through the X chromosome and affects female offspring. All children will not be affected. It is unclear if the diseases caused by this disorder are life threatening.
A pregnant patient learns that her fetus has a genetic anomaly that will affect cognitive and musculoskeletal development. The patient is meeting with her spouse and the nurse and wants to know what options are available to them. What is the first thing that the nurse needs to do to help this couple with decision making? A) Suggest routes to terminate pregnancy. B) Assist the couple in identifying their values. C) Analyze the opinions of extended family members. D) Explain health care options for the baby going forward.
Ans: B Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Physiological Integrity: Reduction of Risk Potential Cognitive Level: Apply Page: 165 Feedback: A useful place to start counseling is with values clarification to be certain a couple understands what is most important to them. Routes to terminate the pregnancy should be the last option. Analyzing the opinions of extended family members should occur after the couple identifies their own values. Explaining health care options for the baby going forward can occur after the couple identifies their values.
A pregnant patient has been counseled to have an amniocentesis. For which genetic conditions should the nurse instruct the patient that this diagnostic test will detect? A) Impetigo B) Trisomy 21 C) Diabetes mellitus D) Phenylketonuria
Ans: B Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Physiological Integrity: Reduction of Risk Potential Cognitive Level: Apply Page: 165 Feedback: Trisomy 21 or Down syndrome is the most common genetic disorder that can be detected through examination of amniotic fluid obtained through amniocentesis. Impetigo, diabetes mellitus, and phenylketonuria cannot be diagnosed through examination of amniotic fluid.
A young married woman tells you that she is going to have a tubal ligation because there are two people with mental retardation in her husband's family, and she is afraid this problem will surface in her children. Which of the following nursing diagnoses would best apply to this couple? A) Spiritual distress related to inappropriate approach to the issue of having children B) Sexual dysfunction related to the possibility of having a cognitively impaired child C) Deficient knowledge of genetically inherited disorders D) Anxiety related to an impending marriage
Ans: C Client Needs: Health Promotion and Maintenance Cognitive Level: Apply Page: 156 Feedback: Cognitive impairment as a single entity is not known to be inherited.
A nurse is reviewing the medical record of a client who has undergone genetic testing. The record reveals the client's complete set of genes, recorded as 46XX. The nurse interprets this as indicating the client's: A) phenotype. B) karyotype. C) genome. D) genotype.
Ans: C Client Needs: Health Promotion and Maintenance Cognitive Level: Apply Page: 157 Feedback: A person's genome is the complete set of genes present (about 50,000 to 100,000). A normal genome is abbreviated as 46XX or 46XY (the designation of the total number of chromosomes plus a graphic description of the sex chromosomes present). A person's phenotype refers to his or her outward appearance or the expression of genes. A person's genotype refers to his or her actual gene composition. A karyotype is a graphic representation of the chromosomes present.
A woman is aware that she is the carrier of a sex-linked recessive disease (hemophilia A); her husband is free of the disease. What frequency of this disease could she expect to see in her children? A) All male children will inherit it. B) All female children will be carriers like she is. C) There is a 50% chance her male children will inherit the disease. D) There is a 50% chance her female children will inherit the disease.
Ans: C Client Needs: Health Promotion and Maintenance Cognitive Level: Apply Page: 158 Feedback: With X-linked inheritance, there is a 50% chance male children will be affected. There is a 50% chance female children will be carriers of the disease.
The nurse is caring for a child with Down syndrome (trisomy 21). This is an example of which type of inheritance? A) Mendelian recessive B) Mendelian dominant C) chromosome nondisjunction D) phase 2 atrophy
Ans: C Client Needs: Health Promotion and Maintenance Cognitive Level: Remember Page: 158 Feedback: Down syndrome occurs when an ovum or sperm cell does not divide evenly, permitting an extra 21st chromosome to cross to a new cell.
Down syndrome may occur because of a translocation defect. This means the: A) infant inherits chromosomal material from only one parent. B) parents have a chromosomal pattern that is exactly alike. C) additional chromosome was inherited because it was attached to a normal chromosome. D) parents are such close relatives that their genes are incompatible.
Ans: C Client Needs: Physiological Integrity: Physiological Adaptation Cognitive Level: Understand Page: 158 Feedback: A translocation defect causes Down syndrome when a 21st chromosome is attached to another chromosome, so disjunction results in an abnormal distribution of chromosomes.
The nurse is making a home visit to a family with a child born with a genetic abnormality. Which observation in the home indicates to the nurse that the parents are adjusting to the newborn's health problems? A) The father walks by the bassinet. B) The father leaves during the visit. C) The mother holds the baby during the visit. D) The mother sits on the sofa while the baby cries.
Ans: C Client Needs: Psychosocial Integrity Client Needs 2: Safe, Effective Care Environment: Management of Care Cognitive Level: Analyze Page: 165 Feedback: Evidence that the parents are adjusting to the newborn with the genetic abnormality is the mother holding the baby during the visit. The father walking by the bassinet or leaving during the visit does not indicate adjustment. The mother sitting on the sofa while the baby cries does not indicate that the mother is adjusting to the newborn's health problems.
During an assessment, the nurse suspects a newborn has a chromosomal disorder. What did the nurse most likely assess in the baby? A) Short neck B) Bowed legs C) Low-set ears D) Slanting of the palpebral fissure
Ans: C Client Needs: Safe, Effective Care Environment: Management of Care Client Needs 2: Health Promotion and Maintenance Cognitive Level: Analyze Page: 163 Feedback: Ears that are low-set ears is a common assessment finding in newborns with the trisomy chromosome abnormalities. Short neck, bowed legs, and slanting of the palpebral fissure are less common findings in a newborn with a chromosomal disorder.
When caring for the couple in which the wife is considering tubal ligation because she is concerned about her children inheriting her husband's family's mental retardation, a primary nursing intervention would be to A) help the woman reject the idea of sterilization. B) strengthen the couple's resolve to remain childless. C) help the couple decide to have children. D) increase the couple's knowledge about genetic inheritance.
Ans: D Client Needs: Psychosocial Integrity Cognitive Level: Analyze Page: 158 Feedback: Education about genetic patterns allows people to make informed decisions.
Syndrome: Down syndrome
Chromosomal Characteristics: -Extra chromosome 21 Clinical Signs in Child: -Cognitively challenged -Protruding tongue -Epicanthal folds - Hypotonia
Syndrome: Turner syndrome
Chromosomal Characteristics: -Only one X chromosome present (45XO) Clinical Signs in Child: -Short stature -Streak ovaries -Infertility -Webbed neck
Syndrome: Trisomy 13
Chromosomal Characteristics: - Extra chromosome 13 Clinical Signs in Child: -Cognitively challenged -Multiple congenital malformations - Eye agenesis
Syndrome:Klinefelter syndrome
Chromosomal Characteristics: -An extra X chromosome present (47XXY) Clinical Signs in Child: -Small testes -Gynecomastia -Subfertility
Syndrome: Cri-du-chat syndrome
Chromosomal Characteristics: -Deletion of short arm of chromosome 5 Clinical Signs in Child: -Cognitively challenged - Facial structure anomalies -Peculiar catlike cry
Syndrome: Trisomy 18
Chromosomal Characteristics: -Extra chromosome 18 Clinical Signs in Child: -Cognitively challenged - Congenital malformations
OUTCOME EVALUATION Examples of expected outcomes for a family with a known genetic disorder include:
Couple states they feel capable of coping no matter what the outcome of genetic testing. Patient accurately states the chances of a genetic disorder occurring in her next child. Couple states they have resolved their feelings of low self-esteem related to birth of a child with a genetic disorder.
Screening and Diagnostic Testing Many screening and diagnostic tests are available to provide clues or to diagnose disorders. Before pregnancy,
DNA analysis or karyotyping of both parents and an already affected child provides a picture of the family's genetic pattern and can be used for prediction in future children.
NURSING DIAGNOSIS Typical nursing diagnoses related to the area of genetic disorders include:
Decisional conflict related to continuation of genetic-affected pregnancy Fear related to outcome of genetic screening tests Situational low self-esteem related to identified chromosomal disorder Deficient knowledge related to inheritance pattern of the family's inherited disorder Readiness for enhanced knowledge related to potential for genetic transmission of disease Altered sexuality pattern related to fear of conceiving a child with a genetic disorder
A great deal of time may need to be spent offering support for a grieving couple confronted with the reality of how tragically the laws of inheritance have affected their lives. What is your role as a nurse ?
Direct counseling is a role for nurses only if they are adequately prepared in the study of genetics, however, because without this background, genetic counseling can be dangerous and destructive
Careful inspection of newborns is often the first time a child with a potential chromosomal disorder is identified.
Infants with multiple congenital anomalies, those born at less than 35 weeks gestation, and those whose parents have had other children with chromosomal disorders need extremely close assessment.
Based on the previous information, draw a family genogram after history, which tells you what ?
Such a diagram helps to not only identify the possibility of a chromosomal disorder occurring in a particular couple's children but also identify other family members who might benefit from genetic counseling. When a child is born dead, parents are advised to have a chromosomal analysis and autopsy performed on the infant. If, at some future date, they wish genetic counseling, this would allow their genetic counselor to have additional medical information.
IMPLEMENTATION Parental reactions to the knowledge their child has a possible genetic disorder or to the birth of a child with a genetically inherited disorder usually involves a grief reaction, similar to that experienced by parents whose child has died at birth (their "perfect" child is gone) Both parents may pass through stages of shock and denial ("This cannot be true"), anger ("It's not fair this happened to us"), and bargaining ("If only this would go away") before they reach reorganization and acceptance ("It has happened to us and it is all right"). For some couples, a genetic disorder is diagnosed during the pregnancy; for others, it may not be discovered until birth or possibly not even until the child is of school age. For these parents, these reactions will occur at that later point of diagnosis. What should you do ?
Support couples in whatever stage they have reached when you care for them and help them work through and adjust to their child's diagnosis.
Test Type: Chorionic villi sampling
Timing:10-12 weeks Process:Biopsy of placenta Risks:Invasive, risk of miscarriage Results:Diagnostic test for karyotype
Test Type:Nuchal translucency
Timing:11-14 weeks Process:Ultrasound to assess thickness at fetus's neck, maternal blood draw Risks:Noninvasive, ultrasound and maternal blood draw Results:Screening test for Down syndrome, trisomy 18 and 13
Test Type: cfDNA
Timing:11≶ weeks, can be done as early as 7 weeks Process:Maternal blood draw, fetal cell fragments in maternal blood are assessed Risks:Noninvasive, maternal blood draw Results:Screening test for abnormal amounts of chromosomes and microdeletions in fetal DNA
Test Type:Amniocentesis
Timing:15-18 weeks Invasive, risk of miscarriage Table Process:Collection of amniotic fluid containing fetal skin cells through maternal abdomen Risks: Results:Diagnostic for fetal karyotype; common chromosomal disorders that can be diagnosed through amniocentesis.
Test Type:Maternal quadruple marker screen
Timing:15-20 weeks Process:Maternal blood draw Risks:Noninvasive, maternal blood draw Results:Screening test for Down syndrome, trisomy 18 and 13
Test Type:Percutaneous umbilical blood sampling
Timing:>17 weeks Process: Fetal umbilical blood sampling through maternal abdomen Risks: Invasive, risk of miscarriage Results:Diagnostic for fetal karyotype and fetal blood diseases
Test Type:Newborn screening
Timing:Day 2-several weeks after birth Process:A blood sample via heel prick or blood draw from newborn Risks:Noninvasive, blood draw from newborn Results:Screening for genetic disorders via serum DNA or other factors
Women over the age of 35 years may be offered a more accurate noninvasive blood test, circulating cell-free DNA (cfDNA) testing, to screen for
chromosomal disorders. Chorionic villi sampling (CVS) and amniocentesis are both techniques that may be offered to women who are older than 35 years of age, or to those whose genetic testing is abnormal, to diagnose chromosomal genetic disorders.
Women having in vitro fertilization (IVF) can have both the egg and sperm examined for genetic disorders of single-gene or chromosome concerns before implantation. With ongoing stem cell research, it may be possible not only to identify
aberrant genes for disorders this way but also to insert healthy genes in their place using stem cell implantation Gene replacement therapy is encouraging in the treatment of blood, neural tube, eye, and congenital metabolic disorders as well as for cancers and immunodeficiency syndromes
A person's genotype refers to his or her
actual gene composition. It is impossible to predict a person's genotype from the phenotype, or outward appearance.
Physical Assessment careful physical assessment of any family member with a disorder, that person's siblings, and the couple seeking counseling is necessary because it is possible that
another family member has such a minimal expression of the disorder, it has gone previously undiagnosed
Genes are the
basic units of heredity that determine both the physical and cognitive characteristics of people. Composed of segments of DNA, they are woven into strands in the nucleus of all body cells to form chromosomes.
A couple's decisions about genetic testing and childbearing do not necessarily remain constant. For example, a decision made at age 25 years not to have children because of a potential genetic disorder may be difficult to maintain at age 30 years because the couple sees many of their friends with growing families. Be certain such couples have the contact information of a genetic counselor. Urge them to
call periodically for news of recent advances in genetic screening techniques or disease therapy so they can remain current and well informed for future planning.
TRISOMY 13 SYNDROME (47XY13+ OR 47XX13+) In trisomy 13 syndrome (Patau syndrome), the child has an extra
chromosome 13 and is severely cognitively challenged. The incidence of the syndrome is low, approximately 0.45 per 1,000 live births. Disorders:Midline body disorders such as cleft lip and palate, heart disorders (particularly ventricular septal defects), and abnormal genitalia are present. Other common findings include microcephaly with disorders of the forebrain and forehead, eyes that are smaller than usual (microphthalmos) or absent, and low-set ears . Most of these children do not survive beyond early childhood
CRI-DU-CHAT SYNDROME (46XX5P− OR 46XY5P−) Cri-du-chat syndrome is the result of a missing portion of
chromosome 5. In addition to an abnormal cry, which sounds much more like the sound of a cat than a human infant's cry, children with cri-du-chat syndrome tend to have a small head, wide-set eyes, a downward slant to the palpebral fissure of the eye, and a recessed mandible. They are severely cognitively challenged
Cytogenetics is the study of
chromosomes by light microscopy and the method by which chromosomal aberrations are identified.
A person's genome is the
complete set of genes present (about 50,000 to 100,000). A normal genome is abbreviated as 46XX or 46XY (the designation of the total number of chromosomes plus a graphic description of the sex chromosomes present).
FUTURE POSSIBILITIES Stem cell research is looking at the possibility immature cells from a healthy embryo (stem cells) could be implanted into an embryo with a known abnormal genetic makeup, replacing the abnormal cells or righting the affected child's genetic composition .Although presently possible, stem cell research is
costly and produces some ethical questions (e.g., Is it ethical to change the life course of a fetus who has no rights? Is it ethical to use embryo cells as a source of stem cells?).
EVIDENCE-BASED PRACTICE If it is predicted during a pregnancy that a couple will have a child with Down syndrome, the couple is asked to make a choice whether they want to continue the pregnancy or terminate it at that point. To discover how couples feel about having a child with Down syndrome, researchers surveyed 2,044 parents on the mailing lists of six nonprofit Down syndrome organizations. The majority of parents reported they are happy with their decision to have their child and find their sons and daughters great sources of love and pride. Ninety-nine percent reported they love their affected son or daughter, 97% reported being proud of them, 79% felt their outlook on life was more positive because of them, only 5% felt embarrassed by them, and only 4% regretted having them. In a following study, siblings also reported their relationship with their affected sibling as a positive one. Less than 10% felt embarrassed, and less than 5% expressed a desire to trade their sibling in for another brother or sister Based on the findings of the previous studies, how would the nurse answer Mrs.Alvarez's question, "Can you imagine how this will change my life?" a. "You're right. Having a genetically affected child can potentially be a serious burden." b. "Don't worry so much about what others think; just concentrate on your own life." c. "Change can create good things in life; I believe as a door closes, a window opens." d. "Would it help if you talk to a family who has a child with Down syndrome?"
d. "Would it help if you talk to a family who has a child with Down syndrome?"
QUALITY IMPROVEMENT Amy Alvarez, 26 years of age, is pregnant with her first child and is experiencing significant stress following her recent diagnostic findings. The nurse would be providing high-quality care if completing which of the following? a. Provided Amy with hope and downplaying the potential for negative outcomes b. Referred Amy to websites and journals in the field of genetics c. Described the most serious consequences of genetic disorders d. Described genetics in a way that directly meets her learning needs
d. Described genetics in a way that directly meets her learning needs
FOR GENETIC ASSESSMENT AND COUNSELING ASSESSMENT Assessment measures for genetic disorders begin with a
detailed family history, preferably of three generations; a physical examination of both the parents and any affected children; and an ever-growing series of laboratory assays of blood, amniotic fluid, and maternal and fetal cells. For example, in the first trimester, women are offered a routine sonogram screening (a nuchal translucency scan) and an analysis of maternal serum levels of α-fetoprotein (MSAFP), pregnancy-associated plasma protein A (PAPP-A), and free beta hCG to evaluate for chromosomal disorders in the fetus.
Genetics is the study of the way such
disorders occur. Because genetics is a constantly changing field of study, it is important for nurses to keep current with new advances so they can appreciate how a new discovery will affect a family and the child's therapy or if it could cure the child
Diagnosis of a disorder during pregnancy with prompt treatment at birth to minimize the prognosis and outcome of the disorder is another route to
explore. Termination of a pregnancy that reveals a chromosomal or metabolic disorder is also an option.
Dermatoglyphics (the study of surface markings of the skin) is also helpful because unusual
fingerprints, abnormal palmar creases, hair whorls, or coloring of hair are also present with some disorders.
A person's phenotype refers to
his or her outward appearance or the expression of genes.
MENDELIAN INHERITANCE: DOMINANT AND RECESSIVE PATTERNS A person who has two like genes for a trait—two healthy genes, for example (one from the mother and one from the father)—is said to be
homozygous for that trait. Many genes are dominant in their action over others. When dominant genes are paired with nondominant (recessive) ones, the dominant genes are always expressed in preference to the recessive genes (a gene for brown eyes, for example, is dominant over one for blue eyes; a child born with a gene for brown eyes and a recessive one for blue eyes will have brown eyes)
An individual with two homozygous genes for a dominant trait is said to be homozygous dominant; an individual with two genes for a recessive trait is said to be
homozygous recessive.
Nurses serve as members of genetic assessment and counseling teams to help obtain the
initial family history, assist with the physical examination, obtain blood serum for analysis, and assist with procedures such as amniocentesis as part of this process.
Failure to heed these guidelines of genetic testing, counseling, and therapy could result in charges of ?
invasion of privacy, breach of confidentiality, or psychological injury caused by "labeling" someone or imparting unwarranted fear and worry about the significance of a disease or carrier state. If couples are identified as being at risk for having a child with a genetic disorder and are not informed of the risk and offered an appropriate diagnostic procedure such as amniocentesis during a pregnancy, they can bring a "wrongful birth" lawsuit if their child is born with the unrevealed genetic disorder
If a couple could not believe what the test showed was true, only when they inspect the baby and see the test was accurate—the child does have a genetic disorder—do they grasp the reality of what has happened. This can result in
long-lasting depression, guilt, or grief for the perfect child they had hoped for at the beginning of the pregnancy.
Genetic Disorders Inherited or genetic disorders are disorders that can be passed from one generation to the
next because they result from some disorder in the gene or chromosome structure. Genetic disorders occur in some ethnic groups more than others because people tend to marry within their own cultural group
Once a woman is pregnant, several other tests may be performed to help in the prenatal diagnosis of a genetic disorder. These include first trimester
nuchal translucency and hormonal screening, cfDNA testing, quadruple test analysis, CVS, amniocentesis, percutaneous umbilical blood sampling (PUBS), and sonography. -All of these tests not only reveal important information but also create ethical and personal concerns for parents because, if an abnormality is discovered, parents are asked to make a decision whether to continue the pregnanc
Chromosomes are threadlike structures of
nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
If a chromosomal aberration exists, it is listed after the sex chromosome pattern. In such abbreviations, the letter p stands for _________ _____ ________and q stands for ________ _____ _________ . For example, the abbreviation 46XX5p—is the abbreviation for a female with 46 total chromosomes but with the short arm of chromosome 5 missing (cri-du-chat syndrome)
p-short arm disorders q-long arm disorders -For example, the abbreviation 46XX5p—is the abbreviation for a female with 46 total chromosomes but with the short arm of chromosome 5 missing (cri-du-chat syndrome)
The CVS and amniocentesis are diagnostic tests that assess the karyotype (a graphic representation of the chromosomes present)—when fetal chromosomes are photographed and displayed, which can provide a definite answer about the
presence or absence of chromosomal disorders.
OUTCOME IDENTIFICATION AND PLANNING When counseling such families, it is helpful to guide them to concentrate on
short-term goals and actions or to help them look first at the immediate needs of their family, the fetus, and the newborn and later on at what type of continued follow-up will be necessary. For instance, after the birth, will the baby need to be hospitalized for immediate surgical correction of accompanying congenital anomalies, or will the parents be able to take the baby home? The kind of special schooling the child will need is a decision that can wait until later.
NURSING RESPONSIBILITIES Nurses play important roles in assessing for
signs and symptoms of genetic disorders, in offering support to individuals who seek genetic counseling, and in helping with reproductive genetic testing procedures.
In humans, each cell, with the exception of the sperm and ovum, contains 46 chromosomes (44 autosomes and 2 sex chromosomes). Spermatozoa and ova each carry only half of the chromosome number (23 chromosomes). For each chromosome in a sperm cell, there is a like chromosome of
similar size, shape, and function in the ovum. Because genes are always located at fixed positions on chromosomes, there are two like genes (alleles) on autosomes for every trait in the ovum and sperm.
Deciding to terminate a pregnancy based on a laboratory finding is rarely easy. If a couple decides to terminate the pregnancy, they need
support for their decision to end the pregnancy. If they decide not to terminate the pregnancy, they may need support during the remainder of the pregnancy and in the days following birth
identify healthcare personnel with whom the parents will need to maintain contact during the next few months such as a
surgeon or an orthopedist. Ensuring the parents have healthcare providers they know they can turn to, especially when they are moving out of the denial stage, helps them move forward to their next step in accepting their child's diagnosis faster. It is also helpful to identify support people who can assist the parents during their time of disorganization. Support people may include the usual family resources, such as grandparents or other family members. In some families, however, these people are as disturbed by the diagnosis as the parents and therefore cannot offer their usual support. Refer parents to helpful websites and other resources when appropriate.
If in the zygote formed from the union of a sperm and ovum, the sex chromosomes are both type X (large symmetric),
the individual is genetically female If one sex chromosome is an X and one a Y (a smaller type), the individual is genetically male
LEGAL AND ETHICAL ASPECTS OF GENETIC SCREENING AND COUNSELING Nurses can be instrumental in making sure couples who seek genetic counseling receive results in a timely manner and with compassion about what the results may mean to future childbearing. Always keep in mind several legal responsibilities of genetic testing, counseling, and therapy including:
• Participation by couples or individuals in genetic screening must be elective. • People desiring genetic screening must sign an informed consent for the procedure. • Results must be interpreted correctly yet provided to the individuals as quickly as possible. • The results must not be withheld from the individuals and must be given only to those persons directly involved • After genetic counseling, persons must not be coerced to undergo procedures such as abortion or sterilization. Any procedure must be a free and individual decision.
Genetic Counseling and Testing It is advantageous for an individual concerned with the possibility of transmitting a disease to his or her children to ask for genetic counseling at a preconception health visit for advice on the inheritance of disease because counseling can serve to:
• Provide concrete, accurate information about the process of inheritance andinherited disorders • Reassure people who are concerned their child may inherit a particular disorder that the disorder will not occur • Allow people who are affected by inherited disorders to make informed choices about future reproduction • Allow people to pursue potential interventions that may exist such as fetal,surgery • Allow families to begin preparation for a child with special needs
Whether one is acting as the nurse member of a genetic counseling team or as a genetic counselor, some common principles apply.
• The individual or couple being counseled needs a clear understanding of the information provided. People may listen to the statistics of their situation ("Your child has a 25% chance of having this disease") and construe a "25% chance" tomean if they have one child with the disease, they can then have three other children without any worry. A 25% chance, however, means with each pregnancy, there is a 25% chance the child will have the disease (chance has no "memory" of what has already happened). It is as if the couple had four cards, all aces, with the ace of spades representing the disease. When a card is drawn from the set of four, the chance of it being the ace of spades is one in four (25%). When the couple is ready to have a second child, it is as if the card drawn during the first round is returned to the set, so the chance of drawing the ace of spades in the second draw is exactly the same as in the first draw. Similarly, the couple's chance of having a child with the disease remains one in four in each successive pregnancy. • It is never appropriate for a healthcare provider to impose his or her own values or opinions on others. Individuals with known inherited diseases in their family must face difficult decisions, such as how much genetic testing to undergo or whether to terminate a pregnancy that will result in a child with a specific genetic disease. Be certain couples have been told all the options available to them and then leave them to think about the options and make their decision by themselves. Help them to understand that no one is judging their decision because they are the ones who must live with the decision in the years to come.
Genetic Assessment and Counseling: goal
•Establish expected outcomes to meet the needs of the family undergoing genetic assessment and counseling.