Pedigrees

Question 1

Genetic Mapping

Answer 1

Distance in relative: 1cM = 1% of recombination frequency between alleles

Question 2

Physical mapping

Answer 2

Measured in base pairs, physical markers between alleles

Question 3

Linkage

Answer 3

Two genes are inherited together more than expected by random chance

Genes must be syntenic to be linked - reside on same chromosome

Question 4

Linkage disequilibrium

Answer 4

Means the genes are linked

Multiply percentages together to find linkage, then compare to actual. If different, they’re in disequilibrium and linked

Question 5

LOD score: genetic linkage

Answer 5

Add all LOD scores, above 3.0 means linked, less than -2.0 not linked

Question 6

Autosomal dominant

Answer 6

Traits appear in equal frequency in both sexes and do not skip generations

Huntington’s, Marian, neurofibromatosis, achondroplasia

Question 7

autosomal recessive

Answer 7

Equal frequency, skip generations

Albinism, cystic fibrosis, glycogen storage diseases, PKU, sickle cell, sphingolipidoses, thalassemia

Question 8

X linked recessive

Answer 8

Appear in males more often, not passed father to son

Fairy, G6PD deficiency, Hunter, hemophilia, duchesse muscular dystrophy

Question 9

X linked dominant

Answer 9

Affects males and females, an affected male must have an affected mother

Question 10

Anticipation

Answer 10

Increased severity or earlier onset of disease in succeeding generations (Huntington)

Question 11

Concordant trait

Concordance

Answer 11

Shared by both members of twin pair

Percentage of twin pairs concordant