Week 2: Non-Mendelian Inheritance Patterns

Question 1

Multifactorial Inheritance

Answer 1

Many genes at different loci-all additive; environment and other triggers contribute

Question 2

Polygenic Inheritance

Answer 2

Many genes at different loci- all additive

Question 3

Studies to do to understand genetic contribution to disease

Answer 3

Family Aggregation, Twin Studies, Adoption Studies

Question 4

Heritability

Answer 4

The total phenotypic variance due to genetic factors; ranges from 0-1

Question 5

General rule for multifactorial RR for 1st degree relative

Answer 5

Square root of the incidence in the population

Question 6

Factors that affect RR for Multifactorial

Answer 6

The greater the number of affected relatives- the greater the risk; the more severely affected the proband- the higher the risk; if the less commonly affected sex is affected- the higher risk

Question 7

4 Rules of Mitochondrial Disease

Answer 7

Maternal Inheritance, Heteroplasmy, Mitotic Segregation, Threshold Effect

Question 8

Heteroplasmy

Answer 8

Coexistence of normal and mutant mtDNA within the same cell

Question 9

3 major features of Kearns Sayre Syndrome

Answer 9

Onset before age 20, PEO, pigmentary retinopathy

Question 10

3 major features of MERRF

Answer 10

Myoclonus epilepsy and ataxia, ragged red fibres, lipomas

Question 11

3 major features of MELAS

Answer 11

Stroke-like episodes, encephalopathy- seizures/dementia, lactic acidosis, ragged red fibers

Question 12

3 major features of NARP

Answer 12

Peripheral neuropathy, cerebellar ataxia, pigmentary retinopathy, lactic acidosis

Question 13

3 major features of LHON

Answer 13

Loss of vision, optic neuropathy, peripapillary telangiectasia

Question 14

Point mutations in mt are more likely to be______, while del in mt are more likely to be _______

Answer 14

Inherited; sporadic

Question 15

3 major features of Leigh Syndrome

Answer 15

Psychomotor regression, hypotonia, feeding/respiratory problems

Question 16

3 major features of MILS

Answer 16

Psychomotor regression, pigmentary retinopathy, seizures

Question 17

Inheritance of CoQ10 Deficiency

Answer 17

AR

Question 18

3 major features of CoQ10

Answer 18

Encephalomyopathy, infantile multi systemic disease, cerebellar ataxia

Question 19

Inheritance of MNGIE

Answer 19

AR

Question 20

3 major features of MNGIE

Answer 20

Opthalmoplegia, GI dysmotility, peripheral neuropathy

Question 21

Method to prevent mt disease in next generation

Answer 21

Oocyte nuclear genome transfer/ pronuclear transfer