Genetic & Congenital Disorders - Exam 1

Myotonic dystrophy

autosomal dominant disorder. progressive muscle deterioration.

Types of Single-Gene Genetic Disorders: (3)

autosome dominant autosome recessive x-linked (recessive)

Sickle cell Anemia

autosome recessive disorder. defective HGB production.

Cystic Fibrosis

autosome recessive disorder. excess mucous build up in lungs, ducs, & GI tract.

Tay-Sach's Disease

autosome recessive disorder. inadequate lysosome breakdown. Gangliosides deposited in CNS neurons, retina. infant neurological deterioration. life span of 4 years.

Thalassemia

autosome recessive disorder. increased RBC production.

Albinism

autosome recessive disorder. lack pigmentation in the skin.

Sex Chromosomes

"X-linked" Female-X Male-Y

Ratio of Affected Parent Transferring Disease in Autosomal Dominant Disorder:

1 affected parent = 1:2 2 affected parents = 3:4

Prime Child Bearing Years

18-24 increase risk of chromosomal disorders when over the age of 24 because of deterioration of eggs.

Autosomes

22 homologous pairs autosomal disorder occurs when there is a defect in 1 or both.

Total # of Chromosomes in Human:

23 22 autosomes 1 sex chromosome

Chromosome Disorders

60 conditions to name. 50% chromosome disorders lead to 1st term miscarriage.

PKU

Phenylketonuria autosomal recessive disorder. inadequate liver production of enzyme phenylalanine hydroxyls. causes severe neurological impairment and can be prevented by not ingesting phenylalanine from processed foods.

Folic Acid Deficiency

results in neural tube defect

Teratogenic Agents

abnormalities during embryonic/ fetal development.

Turner's Syndrome Manifestations:

abnormalities of urinary tract increase number of UTI's puffy eyes short neck (web-like) sterility

Single-gene Disorder

abnormality/mutation of 1 gene. defect on 1 or both autosomes & 1 sex pair.

Pharmacogenetics

assessing individual differences to meds based on gene deficiencies.

Polycystic Kidney Disease

autosmal dominant disorder. renal failure.

Marfan's Syndrome Pathophysiology

autosomal dominant disorder altered fibrillin, elastin, & collagen. diminished strength & elasticity of connective tissue because of inadequate formation. life span of 30-40 years.

Familial hypercholesterolemia

autosomal dominant disorder. excessive cholesterol production.

von Willebrand's Disease

autosomal dominant disorder. inadequate platelet integrity.

Huntington's chorea

autosomal dominant disorder. neurological deterioration.

Multifactorial Inheritance Disorders

caused by multiple genes and environmental factors. traits do not follow a clear-cut pattern of inheritance. may be expressed during fetal life, be present at birth, or expressed later in life.

Examples of Teratogenic Agents

chemicals/drugs (OTC, Rx, or recreational). infectious agents---TORCH: toxoplasmosis, other, rubella, cytomegalovirus, herpes. radiation.

Examples of Multifactorial Inheritance Disorders

cleft lip or palate clubfoot congenital dislocation of hip congenital heart disease pyloric stenosis urinary tract malformation

Manifestations of Down Syndrome:

congenital heart disease leukemia respiratory infections alzheimer's/dementia---if patient lives to age 30 they will almost always have this symptom.

Cocaine During Pregnancy

decrease in utero-placental blood flow maternal hypertension stimulation of uterine contractions which results in premature birth fetal vasoconstriction

Genomics

devoted to all the genes contained in the human genome as well as their interaction with other genes, the individuals environment, and the influence of cultural and psychosocial factors.

Dysmorphic Feature of Down Syndrome:

facial alteration epicanthal folds small ears flat nasal bridge

Fetal Alcohol Syndrome

fetus exposed to toxic ETOH levels (amount unknown). permanent alteration of CNS structure and function. corpus callous especially susceptible which results in wide spread neurological damage.

Autosomal Dominant Disorder

gene abnormalities that limit PROTEIN metabolic functions. (structural protein formation) equal male/female. only the affected person will transfer the disease.

Inherited Disorder

gene mutation in a germ cell (sperm/ovum). trait passed from parent to offspring in germ cell.

Human Genome Project

identified all 30,000 genes in human body all humans have 99.9% same DNA identified genes that code for specific proteins that control cellular activities & new ways to prevent/treat health alterations.

Sex-Linked Chromosomal Disorders

mostly X-linked (recessive) mostly males are affected since they only have 1 X chromosome. affected father transmits to daughter. unaffected male not a carrier. carrier is female.

How Genetic Disorders Occur:

mutation event in group of cells linked by genes. DNA mutation changes formation of single gene. inherited or new mutation.

Meds During Pregnancy

possibility of cytotoxic, anti-metabolic, or growth-inhibiting activities.

Congenital Defect

present at birth but may or may not be diagnosed at birth/hereditary. leading cause of infant deaths.

Why Nurses Need to Know Genetics:

reacting to patients responses to genetic information, concerns and ethical problems. teach individuals about genomic technology. provide nursing care for wide range of genetic disorders.

Autosomal Recessive Disorders

recessive gene mutation that leads to ENZYME problems or inborn errors of metabolism. equal male/female. both parents must be carriers but are not affected.

Klinefelter's Syndrome

sex-linked chromosomal disorder---MALES 1/850 births---very common. extra X chromosome (X, XX, XXX).

Turner"s Syndrome

sex-linked chromosomal disorder--FEMALES. only 1 normal X. 1/2000 births related to advanced paternal age (father).

Hemophilia A

sex-linked chromosomal disorder. bleeding related to clotting factor deficiency. seen more commonly in males maternally.

Duchenne's Muscular Dystrophy

sex-linked chromosomal disorder. fatal muscular degeneration. develops around puberty. life span----teenage years.

Fetal Alcohol Syndrome Manifestations

specific facial alterations (dimorphic) microcephaly stabisums hyperactive/impulsive small stature-stunted growth cognitive deficits seizure disorders

DNA Mutations:

spontaneous-completely random environmental-diet chemicals-contaminates radiation-UV light

Klinefelter's Syndrome Manifestations:

sterility language delay tall stature lower body longer than upper body feminine secondary sex characteristics

Genetics

study devoted to a single gene or group of genes.

Marfan's Syndrome Manifestations:

tall & lanky structure long wingspan lax joints hyper-extensible, long fingers deformities of chest & spine crowded teeth aorta anomalies

Down Syndrome

trisomy 21 (8,9,13,18,22) most common chromosome disorder (1/1000 births). may have maternal link in increase age of mother.