Flashcards in Genetics: Modes of Inheritance Deck (20)
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1
Autosomal Dominant Disease Homozygotes
Usually lethal
2
Achondroplasia
Dwarfism from AD FGFR3 mut
3
Hemizygous
Males are for all genes on X chromosome
4
Allelic Heterogeneity
Different mutations in same gene may cause the same disease
5
Compound Heterozygosity
2 different abnormal alleles at the same locus in an individual
6
Locus Heterogeneity
Different muts in different chromosomes causing the same disease
7
Sex Limitation
Autosomal dominant disorder expressed exclusively in males
8
Mosaicisim
Ocurrence of 2+ cell lines with different genetic or chromosomal constitutions
9
2 Kinds of Mosaicism
Germline - some of germ cells are, mutation transferred to offspring as affected, not mosaic
Somatic - milder/segmental phenotype, cannot be passed to offspring unless present in germline
10
Classic Pedigree of Mt Inheritance of Disease
Woman affected, all her children are affected, none of the children of her sons are affected
11
4 Differences b/w Nuclear and Mt Genome
Mt WAY smaller/fewer genes
Mt ring-shaped
Mt way higher percentage of coding DNA
Mt no introns
12
Heteroplasmy
An mtDNA variant is found only in a portion of cell's mt
13
Homoplasmy
All mtDNA copies have same sequence/mut
14
3 Mitochondrial DNA Point Mutation Diseases
tRNA gene: Mitochondrial encephalomyopathy (MELAS)
ATPase gene: Neuropathy, ataxia, and retinitis pigmentosa (NARP)
ETC Complex 1: Leber's hereditary optic neuropathy (LHON)
15
3 Mitochondrial DNA Large Deletions Diseases
Chronic progressive external ophthalmoplegia (CPEO)
Kearns-Sayre (triad of CPEO, bilateral pigmentary retinopathy, and cardiac conduction abnormalities)
Pearson Syndrome (a lot of shit)
16
Disease Concordance b/w Monozygotic and Dizygotic Twins by Genetic or Multifactorial Cause
Genetic: MZ 100%, DZ up to 50%
Multifactorial: MZ <100%, DZ less than MZ
17
Heritability
Proportion of total phenotypic variance of a condition which is caused by genetic variance
18
Threshold Theory of Qualitative Traits
Susceptibility (liability) depends on the combined small effects of many genes and shows a bell-shaped distribution in the population, and only proportion of individuals exceeding a certain threshold develop the disease
19
Qualitative vs. Quantitative Trait
Qualitative is dichotomous, quantitative continuous
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