Atypical Mendelien Inheritence

Question 1

Genetic anticipation

Answer 1

increasing severity and earlier age of onset in successive generations

Huntiginton disease (repeat located in an exon) 
Myotonic dystrophy (trinucelotide repeat in 3 UTR)

Question 2

Gonadal mosaicism

Answer 2

Two different populations of cells in gonads (testes or ovaries) where each population contains normal genetic compliment but other contains DNA mutation

Question 3

Psuedo-dominant inheritance

Answer 3

Usually an autsomal recessive condition but with a very high frequency carrier or consanguinity

Question 4

Psuedo-dominant inheritance example

Answer 4

Gilberts, intermittent jaundice

inheritance like autosomial dominant

Question 5

Mitochondrail inheritance

Answer 5

maternal inheritance so all offspring of an affected mother will be affected and no offspring of affected father

Question 6

Mitochondrial inheritance disease example

Answer 6

Leighs disease

Question 7

Skewed x-inactivation

Answer 7

reason for occasional maifestation of X-linked recessive conditions in females

Duchennes muscular dystrophy