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Flashcards in genetics Deck (59)
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1

list X linked dominant dz

fragile X, Rett syndrome, hypophosphatemic ricketts, charcot marie tooth syndrome

2

List X linked recessive dz

glucose-6-phosphate dehydrogenase deficiency, duchenne muscular dystrophy, Lesch-Nyhan syndrome, hemophilia A and B

3

environmental factors in xeroderma pigmentosum

degree of exposure to UV light

4

allelic heterogeneity

nonsense vs missense mutation in factor VIII gene and Beta thalassemia- different mutations in same locus produce same phenotype

5

locus heterogeneity

mutations at different loci produce similar phenotype- ie. albinism

6

disease with incomplete penetrance

retinoblastoma and BRCA1 mutations- not everybody with mutated genotype will show phenotype

7

disease with variable expression

hemochromatosis and neurofibromatosis type 1- varying degrees of severity

8

dz with pleiotropy

marfan syndrome, cystic fibrosis, PKU- one gene contributes to multiple phenotypic effects

9

dz with locus heterogeneity

osteogenesis imperfecta

10

prader willi

loss of paternal allele from 15q at an imprinted locus, or inheriting both 15q from mom (25% uniparental disomy). Hyperphagia and obesity, neonatal hypotonia, hypogonadism

11

Angelman syndrome

loss of maternal allele from 15q at an imprinted locus, or inheriting both 15q from dad (5% uniparental disomy). Seizures, ataxia, happy disposition, inappropriate laughter

12

What kind of translocation is philadelphia chromosome

reciprocal

13

Cri Du Chat

microdeletion in p arm of chrom 5

14

hypophosphatemic rickets inheritance pattern and presentation

X-linked dominant disorder resutling in increased phosphate wasting at proximal tubule and results in rickets like presentation. Not responsive to vit D

15

Mitochondrial myopathies inheritance and presentation

mitochondrial mutation- ragged red fibers on muscle biopsy, myopathy, lactic acidosis and CNS diseases. Secondary to failure in oxidative phosphorylation

16

Achondroplasia

Autosomal dominant. Missense mutation in fibroblast growth factor receptor 3 (FGFR3) on chromosome
4 leads to inhibition of cartilage synthesis at
epiphysial growth plate. Dwarfism: long bones are short and thick, cranial and vertebral bones are spared. Autosomal dominant. Missense mutation in fibroblast growth factor receptor 3 (FGFR3) on chromosome
4 leads to inhibition of cartilage synthesis at
epiphysial growth plate. Dwarfism: long bones are short and thick, cranial and vertebral bones are spared. Autosomal dominant. Missense mutation in fibroblast growth factor receptor 3 (FGFR3) on chromosome
4 leads to inhibition of cartilage synthesis at
epiphysial growth plate. Dwarfism: long bones are short and thick, cranial and vertebral bones are spared. Autosomal dominant. Missense mutation in fibroblast growth factor receptor 3 (FGFR3) on chromosome
4 leads to inhibition of cartilage synthesis at
epiphysial growth plate. Dwarfism: long bones are short and thick, cranial and vertebral bones are spared.

17

Polycystic kidney disease

Autosomal dominant. Mutation of the PKD-1 gene on
chromosome 16 (16 letters in PCK). Enlarged kidneys with tubular cysts bilaterally. Renal insufficiency, hematuria, HTN in middle age. Extra renal- liver cysts, berry aneurisms, mitral valve prolapse, colonic diverticulaAutosomal dominant. Mutation of the PKD-1 gene on
chromosome 16 (16 letters in PCK). Enlarged kidneys with tubular cysts bilaterally. Renal insufficiency, hematuria, HTN in middle age. Extra renal- liver cysts, berry aneurisms, mitral valve prolapse, colonic diverticulaAutosomal dominant. Mutation of the PKD-1 gene on
chromosome 16 (16 letters in PCK). Enlarged kidneys with tubular cysts bilaterally. Renal insufficiency, hematuria, HTN in middle age. Extra renal- liver cysts, berry aneurisms, mitral valve prolapse, colonic diverticula

18

Cystic fibrosis

AR. Mutation of CFTR chloride channel on chrom 7. Most common mutation is delta508. Abnormal protein folding. Diagnosis: sweat test. Treatment: N-acetylcysteine (cleaves mucus glycoproteins), infections

19

List the X linked recessive conditions

Be Wise, Fools GOLD Heeds Silly Hope: Bruton agammaglobulinemia, Wiskott-Aldrich syndrome, Fabry disease, G6PD deficiency, Ocular albinism, Lesch-Nyhan, Duchenne MD, Hunter syndrome, Hemophilia A and B, Ornithine transcarbamylase deficiency.

20

Duchennes muscular dystrophy

X-linked recessive. Frameshift mutation of dystrophin gene- ineffective protein. Onset by 5 yrs. Calf pseudohypertrophy, proximal muscle weakness, Gowers maneuver, dilated cardiac myopathy, pulmonary infections, elevated CPK. Muscle biopsy shows necrosis, degeneration and regeneratio of fibers, fatty infiltration, decreased dystrophiin. Diagnosis by PCR

21

Becker muscular dystrophy

X lined recessive. Point mutation in dystrophin gene. Less severe than Duchenne.

22

Familial adenomatous polyposis

Autosomal dominant. Mutation of APC gene on chrom 5 (5 letters in polyp). Thousands of colonic polyps after puberty, adenocarcinoma by age 40. Increased risk for adenocarcinoma of duodenum, ampulla of vater

23

glycogen storage diseases

Autosomal recessive

24

Familial hypercholesterolemia

aka type II hyperlipidemia. Autosomal dominant. Mutation of LDL receptor on chrom 19. Elevated serum LDL, tendon xanthomas (lipid laden macrophages in skin), xanthelasmas around eyes, premature atherosclerosis, early MI

25

PKU

autosomal recessive

26

Sickle cell anemia

autosomal recessive

27

Fabrys disease

X linked recessive

28

hereditary hemorrhagic telangiectasia

Autosomal dominant. Telangiectasias of skin/mucus membranes of lips, tongue, fingertips. Recurrent epistaxis, arterio-venous malformation.

29

Hereditary spherocytosis

autosomal dominant. Defect in ankryin and spectrin (components of RBC cell membranes). RBCs contract to sphere shape and are removed by macrophages in spleen. Splenomegaly, hemolytic anemia, jaundice, pigmented gallstones. Treatment is splenectomy

30

Huntingtons disease

AD. Expansion of CAG trinucleotide repeat on chrom 4 (huntingtin protein). Degeneration of GABAergic neurons in caudate nucleus removes inhibitory input on extrapyramidal circuit- chorea. Manifests btw 20-40yrs. Personality changes, dementia