Pathophysiology Chapter 21 - Congenital and Genetic Disorders

What are 4 chromosomal disorders?

1. Down syndrome 2. Monosomy X (turners syndrome) 3. Polysomy X (Klinefelter syndrome) 4. Trisomy 18 (Edwards syndrome)

What are 4 examples of single-gene disorders (autosomal dominant disorders)?

1. Adult polycystic kidney disease 2. Huntington's chorea 3. Familial hypercholesterolemia 4. Marfan syndrome

What are 6 multifactorial disorders?

1. Anencephaly 2. Cleft lip and palate 3. Clubfoot 4. Congenital heart disease 5. Myelomeningocele 6. Schizophrenia

What are 3 X-linked recessive disorders?

1. Color blindness 2. Duchenne muscular dystrophy 3. Hemophilia A

What are 4 autosomal recessive disorders?

1. Cystic fibrosis 2. Phenylletonuria 3. Sickle cell anemia 4. Tay-sachs disease

What are 9 characteristics of down syndrome?

1. Head is small and has a flat facial profile 2. Eyes are slanted, irises contain Brushfield spots 3. Mouth tends to hang open, large tongue and palate 4. Hands are small and have single crease 5. Muscles tend to be hypotonic, joints are loose 6. Development stages are delayed 7. All are cognitively impaired 8. Sexual development is delayed or incomplete 9. Assortment of other problems

What are 4 potential causes for congenital disorders?

1. May result from single-gene trait or be multi-factorial 2. Single gene disorders are caused by a change in one gene within the reproductive cells 3. Chromosomal abnormalities usually result from an error during meiosis 4. Other disorders are result from premature birth, a difficult labor, or exposure to damaging agents during fetal development

Chromosomes are made up of many genes, which are matched for a function (_______) at a specific location on the paired chromosomes.

Allele

Which method of prenatal diagnosis includes extraction of amniotic fluid from the uterus, and extraction of a sample of the chorionic villus of the fetus so as to examine a sample of fetal tissue?

Amniocentesis

In which type of disorder does the presence of the defect in only one of the alleles produce clinical expression of the disease? Affected parent has a 50% chance of passing on the trait. There are no carriers, and unaffected persons do not transmit the disorder,

Autosomal dominant disorder

Does Fragile X Syndrome occur more in males or females?

Both - Dominant allele is carried on X chromosome

What type of defect do many recessive gene disorders include that cause toxic metabolites to accumulate inside cells or in the blood and tissues, interfering with cell function and possibly causing death?

Enzyme defect

What is a X-linked dominant disorder?

Fragile X Syndrome

What is the most common cause of mental retardation, cognitive deficit, and learning disorders in North American?

Fragile X Syndrome

The effects, such as shade of eye color, vary with the ________ or frequency of expression of the gene among individuals carrying the gene.

Gene Penetration

What refers to the laboratory practices of manipulating genes in living organisms, including microorganisms, plants and animals, and humans?

Gene engineering

What involves the introduction of normal genes into living target cells, sometimes by means of a harmless virus of bacterium, thus changing the cell activity or replacing missing genes?

Gene therapy

If a child is ________ (one normal gene and one disease gene) for a recessive trait, they are a carrier and show no clinical signs of disease.

Heterozygous

What is the term used when twenty-two pairs of autosomes (chromosomes) are arranged by size and shape by a diagnostic graphic?

Karotype

What is an example of a maternal nutrition deficit that may result in spina bifida in the embryo?

Low folic acids levels

What occurs when only one sex chromosome, the X chromosome, is present? This person has only 45 chromosomes. resulting in a variety of physical abnormalities and lack of ovaries.

Monosomy X (Turners syndrome)

Research has recently turned from identification of base pairs in the DNA of specific genes to the proteins that are elaborated when the gene is active. What is the study termed?

Proteomics

What provides the communication link with DNA during the actual synthesis of proteins and helps to maintain control of cell activity?

RNA (ribonucleic acid)

In which type of disorder must both parents pass on the defective gene to produce an affected (homozygous) child?

Recessive

What are commonly classified by inheritance pattern, with the major groups being recessive, dominant, and x-linked recessive?

Single-gene disorders

What does the acronym TORCH mean when considering routine prenatal screening tests for high-risk a=maternal infections?

T - Toxoplasmosis O - Other R - Rubella C - Cytomegalovirus H - Herpes

What are agents that cause damage during embryonic or fetal development and are often difficult to define?

Teratogenic

Which type of disorder has alleles for sex-linked recessive disorders that are usually carried by the X chromosome?

X-linked recessive disorders

Which type of disorder has genes that are recessive but are manifested in heterozygous males who lack the matching normal gene on the Y chromosome?

X-linked recessive disorders