Genetic analysis

Question 1

Mitochondrial inheritance

Answer 1

All children of affected mothers are affected

Leigh’s disease is a movement disorder

Question 2

Penetrance

Answer 2

Proportion of people with the relevant genotype that show the characteristic

Question 3

Expressivity

Answer 3

Degree to which an individual with the relevant genotype displays the characteristics

Question 4

Identifying disease genes by mapping

Answer 4

Pedigree analysis to identify inheritance mode
Recombination mapping with VNTRs/STRs (molecular markers)
Haplotype analysis
Small set of candidate genes identified
Mutations identified by exon sequencing

Question 5

LOD score

Answer 5

Measure of probability of linkage between a gene and marker at a given recombination frequency