Non-Mendelian Inheritance Flashcards
What are the symptoms of Duchenne’s MD?
Fatigue, Muscle weakness, Progressive difficulty walking
How is it decided which X chromsomeis to be inactivated?
It is random
What sex is more affected by x-linked dominant conditions?
Males
What is mitochondrial homoplasmy? Heteroplasmy?
In mitochondrial homoplasmy, a cell has a uniform collection of mtDNA: either completely normal mtDNA or completely mutant mtDNA; heteroplasmy is a mix of mutant and normal mtDNA
What are the symptoms of Glucose 6 Phosphate Dehydrogenase Deficiency?
Hemolytic anemia, paleness, extreme fatigue, tachycardia, rapid breathing or shortness of breath, jaundice, splenomegaly, dark tea-colored urine
X inactivation takes place in which sex?
Females
What is trinucleotide is expanded in Fragile X?
CGG
An inactive X chromosome can be visualized as what structure?
Barr bodies
What triplet is expanded in Huntington’s?
CAG
What is the chance that the son of a carrier female will inherit the mutant allele of an x-linked recessive disorder?
50%
What are the chances that sons of a man affected with an x-linked dominant condition will be affected?
0%
How many genes does the mitochondrial genome contain?
37 genes
What is genetic anticipation?
When the age of onset of a condition becomes younger with each succesive generation and the severity of the disease increases with each generation
What is the mode of inheritance for Friedreich’s Ataxia?
Autosomal recessive
What are the symptoms of Friedreich’s Ataxia?
Dysarthria, Ataxia, Heart problems, Muscle weakness/ fatigue, scoliosis
Is the mutation rate higher for nuclear or mitochondrial DNA?
mitochondrial
What is the mode of inheritance for Rett Syndrome?
X-linked dominant
What is the modeof inheritance of Huntington’s Disease
Autosomal dominant
What are the symptoms of hypophosphatemic rickets?
Short stature, leg bowing, tooth anomalies
What is the mode of inheritance for Duchenne Musclular Dystrophy?
X-linked recessive inheritance
What are the chances that offspring of a mother with a mitochondrial disorder will be affected by the condition? Offspring of an affected father?
100%; 0%
What gene is mutated in Duchenne’s muscluar dystrophy? What are the functions of the wild-type protein?
Dystrophin; Maintaining muscular cell membrane integrity, and required for assembly of synaptic junctions
What are the physical features of fragile x syndrome?
Long face w/ prominent jaw, large ears, macro-orchidism
What is the genetic basis of Trinucleotide Expansion disorders?
Expansion of tandem repeats of three base pairs
What is the most common human enzyme deficiency?
Glucose-6 Phosphate Dehydrogenase Deficiency
What tissues are most heavily impacted by mitcochrondrial disease?
Brain, heart, liver, skeletal muscle, kidney
What is the chance that a daughter of a carrier women of an x-linked recessive disorder will be a carrier?
50%
What is the pathophysiology of hypophosphatemic rickets?
Decreased reabsorption of phosphate by renal tubules, decreased absorption of calcium and phosphorus from the GI tract
What is the mode of inheritance of Hypophosphatemic rickets?
X-linked dominant
What is the mode of inheritance for Hemophilia?
X-linked recessive inheritance
Which sex is more likely to be affected by an x-linked recessive condition?
Males
What is the mode of inheritance of glucose-6-phosphate dehydrogenase deficiency?
X-linked recessive inheritance
What are the symptoms of Huntington’s? Which regions of the brain are particularly affected?
Dementia, memory loss, choreic movements; Caudate and putamen
What trinucleotide is expanded in Friedreich’s Ataxia?
GAA
What is the most common heritable form of moderate mental retardation?
Fragile X syndrome
What are the chances that male offspring of mothers with an x-linked dominant condition will be affected? Female offspring?
50% for both sexes
What are the symptoms of Rett Syndrome?
Slowed growth, microcephaly, loss of movement/coordination, abnormal hand/ eye movements, irritability, seizures, scoliosis
