X-linked mitochondrial disease Flashcards
1
Q
X-linked disorders
A
- Mutation on the X-chromosome
- Mostly males affected
- No male to male transmission
2
Q
X-linked Recessive Inheritance
A
- Phenotype expressed in all males who carry the affected genotype
- Phenotype expressed in homozygous females only
- Heterozygote females are carriers
3
Q
X-linked Dominant Inheritance
A
Expressed in male hemizygotes and female heterozygotes
4
Q
Fragile X Syndrome
A
- X-linked dominant
- Trinucleotide repeat disorder- CGG
- Most common cause of inherited developmental delay
- Anticipation
- Maternal transmission bias
5
Q
Fragile X clinical manifestations
A
- Intellectual disabilities
- Dysmorphic features: large ears, long face, macroorchidism
- Autistic behavior
- Social anxiety
- Hand flapping/biting
- Aggression
6
Q
Fragile X gene
A
FMR1
7
Q
fragile x chrom
A
xq27.3
8
Q
fragile x protein
A
FMRP
9
Q
FMRP function
A
Protein is essential form normal cognitive development and female reproductive function
10
Q
fragile x is cause by
A
Increase in the trinucleotide repeat number methylate the gene and the protein is not made
11
Q
X Chromosome Inactivation
A
- Equal expression of X-linked genes
- Random
- Mosaic for maternal and paternal X chromosome
- Does not occur in males
12
Q
Duchenne muscular dystrophy
A
- Progressive muscular weakness proximal > distal
- Calf hypertrophy
- Dilated cardiomyopathy
- CK levels 10x
- Onset before the age of 5
- Wheelchair bound before 13
- Death in their 30’s
- Absence of Dystrophin
13
Q
Becker Muscular Dystrophy
A
- Progressive muscular weakness proximal > distal
- Dilated cardiomyopathy
- CK levels 5x
- Onset later
- Wheelchair bound after 16
- Death in their 40’s
- Abnormal quantity or quality of Dystrophin
14
Q
hemophilia A clinical manifestation
A
- Spontaneous bleeds into joints, muscles or intracranial
- Excessive bruising
- Prolonged bleeding after injury or incision
- Delayed wound healing
15
Q
hemophilia A gene
A
F8
