Ch5

hereditary and disease

22

How many total pairs of autosomes?

2

How many total sex chromosomes?

prophase

chromosomes contract and develop into two sister chromatids

centromere

spot where chromatids are joined together

dissolves

As prophase progresses, the nuclear envelope…

prometaphase

cells get ready to divide at metaphase

meiosis

sexual reproduction, one cell divide twice to form 4 daughter cells

haploid

daughter cells have hald # of chromosomes of parent cells

Achondroplasia

autosomal dominant disorder; short limb dwarfism: faulty cartilage growth, prominent lower back curvature

Autosomal dominant disorders

Huntington’s disease, polydactyly, achondroplasia, Marfan syndrome, hypercholesterolemia

autosomal recessive disorders

cystic fibrosis, hemochromatosis, galactosemia, sickle cell anemia, tay-sachs disease, albinism

Phenylketonuria (PKU)

deficiency of enzyme phenylalanine hydrixylase; mental deficiency, tested at birth

restriction of phenylalanine in diet

treatment for PKU

Hemochromatosis

excessive iron absorption and storage; bronze skin, diabetes dye to tissue destruction, scarring of liver, heart failure

treatment for hemochromatosis

recurring phlebotomy and medication to bind iron

Tay-Sachs Disease

absence of lysosomal enzyme Hexose Amidase A; gradual deterioration of child and red spot in center of retina; most common in Jewish population of Eastern Europe

Sickle Cell Anemia

reduced oxygen environment, causing red blood cell to change shape and plug vessels and capillaries

10%

percentage of African Americans w/ sickle cell anemia

Cystic Fibrosis

abnormality in transport of sodiym chloride across cell membranes; thickened mucus secretion in pancreas, liver and lungs. Over time, lungs develop pneumonia and lose pulmonary function; slow growth

Fragile X Syndrome

x chromosome has constricted neck due to a lot of CGG repeats; patients have long narrow faces, possible mental deficiency, prominent jaw and forehead, enlarged testes in males

Down Syndrome

extra chromosome 21, possible cardiac defect, mental deficiency; more common in pregnancy later in age

Turner’s Syndrome

gonadal dysgenesis; phenotypically female, genetically male;

• delayed puberty, short stature, infertility, heart defects, possible learning impairment

Klinefelter’s Syndrome

• phenotypically men, XXY genotype

• possible learning impairment, underdeveloped testes, breast development

Amniocentesis

prenatal diagnostic procedure that involves removing amniotic fluid from uterus after 14th week to test for genetic and chromosomal abnormalities in the fetus; detect approx. 200 genetic diseases

Chorionic villus sampling

prenatal diagnostic test, take tissue sample from placenta to analyze for genetic abnormalities; can tell gender and chromosomes, allow for options of termination or preparation for child w/ special needs

congenital disorders

present at birth; usually from failure in development process during embryonic stage or in first 2 months of pregnancy; cerebral palsy, cleft lip

Karyotype

complete chromosomal composition of the nucleus

diploid

cell has 2 complete sets chromosome sets

genome

complete set of DNA in a living thing

familial disease

consistently appear in families

multifactorial trait

characteristic of familial disease; cause of disease does not seem to be single gene but the effect of several working together

Hermaphroditism

sex reversal or intersex, chromosomal sex is different from anatomic sex

Pseudohermaphrodites

have either testes or ovaries, usually non-functional, but remainder of anatomy is mixed; external genitalia are ambiguous

gene therapy

procedure that involves identification, manipulation, and transfer of genetic material into patient to replace or repair defective genes; delivered in viral package of injection

Thalomide

• drug used in 50s-60s during early pregnancy for morning sickness

• babies born without limbs or had flipper-like appendages