Flashcards in Autosomal Domiant Deck (9)
Classic features of an Autosomal Dominant pedigree
* disease is only passed from affected parents. (not hidden in carriers)
* affects every generation (50:50 chance of being passed on)
* affects M / F equally
Gene responsible for Achrondroplasia?
FGFR3 - fibroblast growth factor receptor 3
is a tyrosine kinase receptor
chr 4p16.3 nucleotide 1138
amino acid substitution
Inhibits chondrocyte proliferation and differentiation
pure dominant vs incompletely dominant
purely dominant: homozygous and heterozygous clinical presentations are the same
incompletely dominant: homozygotes are affected more severely
What percent of achondroplasia cases are a new mutation?
Give some examples of disease that are autosomal dominant but show reduced penetrance.
2. brca mutation (breast cancer)
3. huntingtons disease
different severity, onset etc of a disease in people with the same allele
Some examples of disorders of variable expressivity
neurofibromatosis type 1
van der woude
Van Der Woude syndrome?
IRF6 gene on chr1 ; haploinsufficiency --> auto. dom.
cleft lip, cleft palate, hypodontia, narrow arched palate, congenital heart disease, heart murmer, cerebral abnormalities, polythelia, ankyloglossia, adhesions btwn upper and lower gum pads, syndactyly