Patterns of single gene inheritance

Question 1

locus

Answer 1

PHYSICAL location of a specific gene on a chromosome

Question 2

Compound heterozygous

Answer 2

Both alleles mutant but mutations are at different locations in the gene

Question 3

Allelic heterogeneity

Answer 3

Different mutations, same phenotype

Question 4

Phenotypic heterogeneity

Answer 4

Mutations on same gene (same organ system, for example, affected), different phenotype

Question 5

Locus heterogeneity

Answer 5

Mutations in different locations on the chromosome or in general can cause the same phenotype

Question 6

Pleitropy

Answer 6

One gene affects multiple traits

Question 7

Polygenic

Answer 7

Multiple genes cause one phenotype

Question 8

What can you predict from the pedigree?

Answer 8

Inheritance pattern and genotype (Aa vs aa)

Question 9

Pedigrees are used to establish the pattern of transmission of

Answer 9

single gene disorders

Question 10

Factors that can confound pedigree interpretation (4)

Answer 10

1. early lethality (death at birth or in utero, difficult to track and add to information)
2. small family size (if there is other factors that make traditional mend inheritance difficult to use)
3. non-mendelian inheritance (i.e. TRD)
4. Variable age of onset (could have disease eventually and just not yet)

Question 11

Genetic isolates

Answer 11

other genetic reasons, intermarriage for ethnic reasons (self-imposed isolation

Question 12

inbreeding

Answer 12

breeding in a geographically isolated area