Flashcards in Autosomal Dominant Deck (46):
Law of Segregation
each parent passes one randomly selected allele for each trait
Law of Independent Assortment
separate genes are passed independently of one another
Autosomal Dominant traits are manifested in _______.
homozygotes and heterozygotes
Autosomal Dominant traits map to an _______.
Autosomal Dominant traits are manifested in which gender?
both males and females
Autosomal Dominant traits can be passed on by which parent?
Autosomal Dominant pedigrees have ______ patterns.
It is rare to have a _______ autosomal dominant condition.
having the genotype and showing the phenotype
100% penetrance means?
If you have the genotype, you will always show the phenotype
Name a disease with 100% penetrace.
What is the incidence rate of achondroplasia?
What is the new mutation rate in achondroplasia?
What are the signs and symptoms of achondroplasia?
short stature, Rhizomelic limb shortening, trident hands, frontal bossing, small foramen magnum, genu varum
Achondroplasia is caused by a ___ mutation in the _____ gene on chromosome ____.
amino acid substitution of G to A; FGFR3; 4
Paternal age effect can be seen in diseases such as _____.
What is the paternal age effect due to?
increased error rates in spermatogenesis in older men
homozygotes and heterozygotes are equally affected
homozygotes are more severely affected
Which diseases have reduced penetrance?
retinoblastoma, BRCA, Huntington Disease
Achondroplasia is fatal in the ______ form.
What is the incidence rate for retinoblastoma?
1:15,000 live births
Retinoblastoma associated protein regulates _____.
the cell cycle
Retinoblastoma is ____ penetrant.
Retinoblastoma gene is ____ on chromosome ____.
On a pedigree, you might see incomplete penetrance when _____.
a generation is skipped
the degree to which the phenotype is expressed given a genotype
Name 2 diseases with variable expressivity.
1) neurofibromatosis type 1
2) osteogenesis imperfecta type 1
Neurofibromatosis type 1 incidence rate? new mutation rate?
1:3000 births; 50%
How is neurofibromatosis type 1 clinically diagnosed?
café-au-lait spots, neurofibromas, freckling in axillary or inguinal areas, optic glioma, lisch nodules, osseous lesions, 1st degree relative
1st degree relative
share 50% of your genes (parents, siblings, children)
What is the mutation in neurofibromatosis type 1? What kind of mutation? What chromosome?
NF1; loss of function; 17
What is the incidence rate of osteogenesis imperfect type 1?
What are the signs and symptoms of osteogenesis imperfect type 1?
multiple fractures, mild short stature, adult onset hearing loss, blue sclera
What is the mutation in osteogenesis imperfect type 1? What does it do? Which chromosome?
COL1A1; reduces collagen production by half; 7
What is the incidence rate of Marfan Syndrome? What is the new mutation rate?
What is the mutation in Marfan Syndrome? What does it do? Which chromosome?
FBN1; decreases microfibrils and increases flexibility and stretching of tissues; 15
a mutation in more than one locus causing the same clinical condition
What is an example of a locus heterogeneity disease?
AD polycystic kidney disease
What is the incidence rate of AD polycycstic kidney disease? What is the de novo mutation rate?
What are the clinical symptoms of AD polycycstic kidney disease?
bilateral renal cycts, cysts elsewhere, vascular abnormalities, renal disease
What is the mutation and chromosome in AD polycycstic kidney disease?
1) PKD1 of chromosome 16 (85% of cases)
2) PKD2 of chromosome 4 (15% of cases)
What is the incidence rate of familial hypercholesterolemia? What is the new mutation rate?
1:200-500; very low
What are the clinical manifestations in familial hypercholesterolemia?
very high cholesterol and LDL; xanthomas; CAD and death
cholesterol deposits under the skin