Patterns of Inheritance Flashcards
When an allele of a gene produces several phenotypic effects
Pleiotropy
The probability that gene will have any phenotypic expression at all
Penetrance
The severity of expression of the phenotype
Expressivity
Renal cysts diagnosable by ultrasound, leads to progressive renal failure, extrarenal problems including cysts in liver or pancreas, cerebral aneurysm, mitral valve prolapse (autosomal dominant)
Polycystic kidney disease (ADPKD)
Polycystic kidney disease is caused by a defect in the _____ gene 95% of the time and _____ 5% of the time
PKD1 and PKD2
Inborn errors of metabolism typically have what type of inheritance
autosomal recessive
Autosomal recessive. Severe mental and physical deterioration, develop normally for first few months of life but then deterioration and death occur by 2-3 yo due to accumulation of ganglioside GM2 in neurons. Cherry red spot on retina
Tay-Sachs Disease
Autosomal recessive. Mental retardation, fair skin, eczema, epilepsy, preventable if prompt dietary treatment given. Mutations in liver enzyme phenylalanine hydroxylase.
Phenylketonuria
% of genes shared between first degree relatives
50%
% of genes shared between second degree relatives
25%
% of genes shared between third degree relatives
12.5%
% of genes shared between fourth degree relatives
6.25%
Marriage between persons with the same surname
Isonymous marriage
X-linked recessive. Coagulation disorder characterized by the inability of blood to clot, leading to hemorrhaging into joints and muscles, even from minor injuries
Hemophilia A
X-linked recessive. Progressive muscle weakness, pseudohypertrophy of calf muscles, onset in early childhood, death by 30s.
Duchenne Muscular Dystrophy
X-linked dominant. Rare mental retardation syndrome in females, usually lethal in males. Defect in methyl-CpG-binding protein9. Normal initial development followed by rapid decline in progression plus onset of ataxia (inability to coordinate muscle activity during voluntary movements) and dementia
Rett Syndrome
X-linked dominant. Ability of kidney to reabsorb phosphate is reduced leading to hypophosphatemia
Hypophosphatemic rickets / Vitamin D-resistant rickets
Mitochondrial. Rapid, bilateral loss of central vision due to optic nerve death in young adults.
Leber’s Hereditary Optic Neuropathy (LHON)
Mitochondrial. External opthalmoplegia (paralysis of eye). Pigmentary degeneration of the retina and cardiomyopathy
Kearns-Sayre Syndrome (KSS)
Myoclonic epdepsy and ragged red fiber disease has what type of inheritance
Mitochondrial
Pertains to set of genes carried by both the X and Y chromosomes. These genes are involved with disorder known as sex reversal.
Pseudoautosomal inheritance
Probability of either of two mutually events occurring. What do you do?
Probability is the sum of their individual probabilities. Additivity principle.
Probability of two or more independent events occurring together. What do you do?
Probability is the product of their individual probabilities. Independence principle.
In the binomial equation, which term designates the probability of a single affected child.
A
