Genetics & Human Disease Flashcards
Each person is estimated to carry how many deleterious genes?
5-8
Define Pleiotropism
A mutation in a single gene can lead to many effects
CF
Define Genetic Heterogeneity
Mutations at several loci may produce the same trait
Diabetes, PKU
Define Autosomal Dominant
Only need 1 parent to carry defective gene
Define Autosomal Recessive
Both parents must carry defective gene
Two Austosomal Dominant diseases?
Huntington’s disease
Familial hypercholesterolemia
Define Huntington’s disease
Triplet repeat on chromosome 4
Dysfunctional protein builds up leading to toxicity at the GABA neurons
Define Familial hypercholesterolemia
Defective LDL receptor –> inability to bind LDL and transport to liver
Three Autosomal Recessive Disease
PKU
CF
Sickle cell anemia
Define PKU
Defective phenylalanine hydroxylase –> build up in the CNS leading to mental retardation
Define CF
Defective chloride ion channel –> thickened mucus secretion
Define Sickle Cell Anemia
Defective hemoglobin which precipitates at low O2 tension
Who is most effect by X-linked disease and why?
Males
They only have only one X (always from the father)
Three X-Linked Recessive Diseases
Hemophilia A&B
G6PD deficiency
Diabetes insipidus
Define Hemophilia A&B
Defect in clotting factors (8&9) –> prolonged bleeding