Unusual Patterns of Inheritance

Question 1

What is the pseudoautosomal region?

Answer 1

the tip of the p and q arms of X and Y that cna sometimes cross over, making traits look like they aren’t sex linked

Question 2

Most important pseudoautosomal region gene

Answer 2

SHOX gene
Short stature homeobox gene. Haploinsufficiency causes short statue in Turner Syndrome
Pseudoautosomal Dyschondrosteosis (Dominant SHOX mutation)

Question 3

If SRY absent/mutated…

Answer 3

Female pathway

Need both Xs for proper maturation of the ovaries

Question 4

Explain Uniparental Disomy

Answer 4

Inheritance of both homologs of a chromosome pair form the same parent

Question 5

What is Trisomic Rescue

Answer 5

Originally trisomic chromosome ditches one to be normal

Question 6

Imporant refections of mitochondrial DNA disease

Answer 6

Ox Phos problems that usually make neurologic probs

MELAS, MERRF, Leigh, Deafness

Question 7

Important details about Myoclonic Epilepsy with Ragged Red Fibers (MERRF)

Answer 7

Childhood-Adulthood
Myopathy
Dementia, myoclonic seizures, ataxia
Deafness
Variable presentation

Question 8

What is Leigh Syndrome

Answer 8

Mitochondrial necrotizing encephalopathy
Onset at 1.5
More severe than NARP

Question 9

What does heritability mean

Answer 9

Measure of the contribution of genetics to a disease. Score ranges from 0 (environmental) to 1 (genetic)

Question 10

What does concordance/Similarity measure

Answer 10

Assesses correlation between relatives with regard to presence of a trait