pedigrees

What is a pedigree?

A pictorial representation of a family history

What do circles and squares represent?

Circle: female; square: male

What do filled and unfilled symbols represent?

Filled: affected with trait; unfilled: unaffected

How are generations numbered?

Generations are numbered with roman numerals

How are individuals numbered?

Individuals are numbered with numbers

Autosomal recessive

equal frequency of females and males, tends to skip generations; more likely to appear among progeny of related parents

Autosomal dominant

equal frequency of males and females, affected persons have at least one affected parent, does not skip generations

X-linked recessive

appear more frequently in males, skips generations, affected males usually born to unaffected mothers

X-linked dominant

does not skip generations, affected sons have an affected mother

Y-linked

appears only in males, passed from fathers to all sons

consanguinity

mating between related individuals