Gen Complications Mastick Flashcards
Dominant and recessive disorders refers to the (blank) of a disease.
clinical manifestation
What is this:
different mutations in the same gene (alleles)
allelic heterogenity
Allelic heterogeneity can cause what?
- different modes of inheritance (dominant vs. recessive)
- different severity of disease.
Allelic heterogenity can affect diagnosis, prognosis, and/or progression of disease,
as well as (blank) in the family.
recurrence risk
What does cystic Fibrosis exhibit?
Allelic heterogeneity
Name that disease:
• One of the most common single gene disorders, autosomal recessive,
1/2000- 1/4000 in Northern European Caucasian population.
• Pleiotropic disorder.
Caused by mutation in CFTR transmembrane receptor
Cystic Fibrosis
Name that disease:
affects the epithelia in several organs resulting in a complex, multisystem disease that includes the exocrine pancreas, intestine, respiratory tract, male genital tract, hepatobiliary system, and exocrine sweat glands.
cystic fibrosis
the great majority of individuals with CF are pancreatic (blank)
insufficient
In CF, the overall median survival is (blank) years. A gender difference is present in CF with greater median survival in who?
31.6
males than in females
Disease expression varies by severity of CFTR mutations, (blank), and environmental factors.
genetic modifiers
How many mutations have been identified on the CFTR gene?
hundreds
Different mutations have different effects on (blank)
protein expression/activity.
The more severe the effect on CFTR function, the more severe the (blank).
the disease
what is the most common allele of CF?
delta 508
Familial isolated growth hormone deficiency (IGHD) has both (blank) and (blank) forms of this disease.
dominant and recessive
IGHD mutation is in a single gene (GH1), therefore it is showing (blank).
allelic heterogenity
GH1 shows haplo(blank)
sufficiency
The recessive form of IGHD mutations leads to reduced expression of (blank)
GH
The dominant form of IGHD mutations leads to altered (blank).
GH protein product
A dominant negative allele in IGHD results in what?
greater than 50% reducion in GH1 with one mutant allele.
What type of mutations have an altered gene product that acts antagonistically to the wild-type allele.
dominant negative alleles
What kind of heterogenity does osteogenesis imperfecta exhibit?
allelic heterogenity
Name that disease;
Clinically heterogeneous disease characterized by brittle bones.
- All forms caused by defects in type I collagen.
-All forms autosomal dominant, but differ in severity.
Osteogenesis imperfecta
Type I osteogenesis imperfecta (OI) is more common or less common than type II? Is it more severe or less severe?
more common 1/15,000 individuals
less sever
Why type of mutation does both Type II and Type I OI have ?
How come they differ in severity?
a single mutation in the COL1A1 gene on chromosome 17
Differences in severity are due to differences in the mutations at the molecular level.
Explain the differences at the molecular level b/w type I and type II of OI?
type I has reduced alpha 1 collagen which results in left over unpairs alpha 2 which is degraded.
Type II has mutant alpha 1 and any alpha 2 that pairs with it will be destroyed.
Name that disease:
Brittle bone disease caused by defects in COL1A1 leading to loss of expression (or rapid degradation) of the defective a1(I) collagen molecules. Normal collagen formed, but only 50% of normal level (excess a2(I) chains are degraded).
Type 1 OI
Name that disease:
Perinatal lethal bone disease caused by defects in
COL1A1 genes leading to mutant forms of a1(I)
collagen being expressed. Forms abnormal collagen complexes with the normal proteins; results in less than half of the normal protein level. Protein Suicide.
Type II OI