genetics Flashcards
Histone acetylation
weakens the DNA-histone bond and makes DNA more accessible for TF and RNA polymerase
Histone deacetylation
- what condition causes increased histone deacteylation?
silences genes
- Huntington’s Huntingtin protein
pleiotropy
one gene contributes to multiple phenotypic effects
locus heterogeneity
- ex
mutations at different loci have similar phenotype
- albinism
allelic heterogeneity
- ex
mutations at same allele locus can produce same phenotype
- beta-thalassemia
heteroplasmy
presence of both mutated and normal mtDNA
results in variable expression in mitochondrila inheritance d/o’s
uniparental disomy
2 chromosomes from 1 parent and none from other
heterodisomy –> error in what
isodisomy –> error in what
meiosis I
meiosis II or potzygotic chromosomal duplication of one and loss of other parent
Prader Willi and Angelman
imprinting d/o
- if you lose your dad, you get fat
- if you lose your mom you have inappropriate laughter
Edwards
trisomy 18 (E for election at age 18)
first trimester: low hcg and PAPP-A
quad screen: low afp, hcg, estriol, inhibin A
Patau
trisomy 13 (P for puberty at age 13)
first trimester: low bcg and PAPP-A
nuchal translucency
Palate, Polydactyly, holoProsencephaly
Down
first trimester: low PAPP-A and high hcg
quad screen: low afp and estriol; high hcg and inhibin A
cri du chat
microdeletion of 5p
microcephaly, MR, mewing, epicanthal folds, VSD
Williams
microdeletion of 7q (elastin gene)
- hypercalcemia, elf-like
22q11
what branchial pouches
DiGeorge and velocardiofacial syndrome
CATCH 22
- cleft
- abnormal facies
- thymic aplasia
- cardiac
- hypoCa 2/2 parathyroid aplasia
3rd and 4th branchial pouch aberrant dev’t
