pedigrees

sex(x) linked recessive

1. both parents have it, all offspring have it.
2. if a mother has it, all the sons will have it.
3. if a daughter has it, the father will also have it.
note- male bias (not a rule)

sex(y) linked

1. if a father has it, all the sons will have it
2. if a father doesn't have, no sons will have it
3. no females have it.

mitochondrial inheritance

1. if mom has it, all offspring have it
2. if mom doesn't have, non of the offspring will have it.

pedigree key

Square= male circle=female
Filled in=recessive or trait looking for
not filled in=dominant or trait looking for
crossed out- dead
pointing to it- proband/ the person of interest

autosomal dominant

rules-
1. if offspring has, at least on parent has
2. cannot skip generations
3. just ignore epistasis

autosomal recessive

1. if both parents have it, all of the offspring have it

sex(x) linked dominant

1. if an offspring has it, at least one parent has it
2. cannot skip generations
3. if a father has it, all daughters will have it
4. if a son has it, his mother will also have it.
note- there is a female bias (this is NOT a rule just a pattern)
cannot determine if autosomal dominant or x-linked dominant so use the note. will be asked which is more likely