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M2M Unit II > Mitochondrial Inheritance > Flashcards

Flashcards in Mitochondrial Inheritance Deck (23):
1

Mitochondrial DNA is passed from the _____ to _____.

mother; all of her children

1

Mitochondrial diseases are disorders caused by _____.

dysfunction of the respiratory chain

2

What is the mutation in Kearns-Sayre?

a large deletion of mtDNA (~12 genes)

2

What are the signs and symptoms of MELAS?

muscle weakness, seizures, repetitive stroke-like episodes, elevated lactic acidosis

4

replicative segregation

multiple copies of mtDNA are randomly sorted among new mitochondria

4

What is the incidence rate of MERRF? New mutation rate?

1:400,000; very low

5

What does MELAS stand for?

mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes

6

What are the signs and symptoms of MERRF?

weakness, myotonia, seizures, ataxia, dementia, ragged-red muscle fibers

6

What is the incidence rate of Leber Hereditary Optic Neuropathy?

1:30,000

7

threshold effect

too much mutated mitochondrial DNA in a cell- problems start presenting

8

What is mutated in MERRF?

MT-TK gene

9

What is MERRF?

myoclonic epilepsy with ragged-red fibers

11

What are the clinical manifestations of Kearns-Sayre?

eye problems, cardiac conduction effects, ataxia, deafness, kidney problems

13

What are 4 mitochondrial diseases?

1) Kearns-Sayre 2) MELAS 3) MERRF 4) Leber Hereditary Optic Neuropathy

15

Mitochondrial DNA encodes ____ genes.

37

15

What is the mutated gene in Leber Hereditary Optic Neuropathy?

several mitochondrial genes

17

What is the MELAS mutation?

several different genes with same manifestation; usually MT-TL1

18

What is the incidence rate of Kearns-Sayre?

1:100,000

19

What is the incidence rate of MELAS? What is the new mutation rate?

1:300,000; very low

20

ataxia

abnormal gait

21

heteroplasmy

receiving both some mutated and some normal mitochondria

22

What are the signs and symptoms of Leber Hereditary Optic Neuropathy?

vision loss

23

Why does Leber Hereditary Optic Neuropathy show reduced penetrance?

50% of males get vision loss, but only 15% of females do