Genetics: Test 2

ATP is produced in the respiratory chain by

Mitochondrial defects may cause decreased _____.
Result =

Mitochondrion contains its own genome.
DNA self-replicates within mitochondria.
Each mitochondria has several copies of mtDNA (5-10)
Each cell has many mitochondria

Mitochondria are abundant in oocyte.
How many mitochondria are found in sperm?

mtDNA codes for __ genes
rRNA's?
tRNA's?
Oxphos polypeptides?

What has a higher mutation rate, mtDNA or nuclear DNA?

Mitochondrial mutations accumulate as we age; therefore, mtDNA mutations are found even in healthy individuals

A cell may have a mixture of normal and mutant mitochondria.  This is referred to as?

Which organs or tissue are the most vulnerable to mitochondrial disorders?

Defective OxPhos causes an increase in _______ in mitochondria and the cytoplasm.

Elevated NADH/NAD ratio leads to elevation of ?
Leads to impaired function of?

Provocative tests for mitochondrial disorder

Progressive adult muscle weakness.

How to diagnose a mitochondrial myopathy diagnosis

MERRF

80% of MERRF mutation people have a mtDNA mutation in what gene?

MELAS

MERRF have mutation in
MELAS have mutation in

Kearns-Sayre Syndrome's symptoms are referred to as

8993T>G in the ATP6 gene most common mutation for mitochondria encephalomyopathy _____

Diabetes mellitus shows some evidence of follwing a maternal inheritance pattern.  Mutation is in?

Subacute necorizing encepalomyopathy:
Lactic acidosis
Bilateral symmetrical focal regions of necrosis in the thalamus, pons, inferior olives (brain) and spinal cord

Most cases are due to mutations in nuclear genes for ____

•Skewed X chromosome inactivation can result
in females manifesting signs of X-linked recessive disorders that are typically seen in affected malesExample:girls with Duchenne
muscular dystrophy or with hemophilia A

•Females with Turner syndrome and a 45,X
chromosome constitution also manifest the clinical signs of an X-linked recessive disorder if their single X chromosome carries a mutant allele.

•Females with an X-autosome
translocation have preferential inactivation of their normal X chromosome (to
maintain activity in the autosomal fragment), sometimes resulting in
manifestations of an X-linked recessive disorder.

•The union between an affected father and a
carrier mother can produce a daughter affected with an X-linked disorder;
always consider possible consanguinity/incest.

EEC Syndrome (AD Inheritance)

Isolated defects are the presentation of

Familial clustering of a trait with no distinctive Mendelian inheritance pattern.
Recurrence risks are _____, not Mendelian

Multifactorial inheritance has much higher risk for ____
Recurrence risks increase with the severity of the disorder
Ex.

Malformation Sequence
Defect in neural groove closure prior to __ days
Folate-sensitive

Neural Tube:  Anterior closure defect

Neural Tube Defects:  Cervical and upper thoracic defect

Neural Tube Defects:  Mid-to-caudal neural groove defect

Myotonic Dystrophy is a repeat expansion mutation of