Autosomal dominant inheritance: the basics 18.02.03

AUTOSOMAL DOMINANT INHERITANCE Parents Parents have two copies of autosomal genes: one copy on each of a particular pair of chromosomes

AUTOSOMAL DOMINANT INHERITANCE Parents A parent with an autosomal dominant disorder has one copy of an altered gene and one normal gene of the particular pair

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes The unaffected parent passes on one or other of his/her normal genes into the eggs or sperm The affected parent passes on either the altered gene or the normal gene into the eggs or sperm

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes There are four different combinations of the two genes from each parent

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Offspring This child has inherited the altered gene from the affected parent and one of the normal genes from the unaffected parent

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Offspring This child has inherited the altered gene from the affected parent but the other normal gene from the unaffected parent

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Offspring

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Offspring This child has inherited the normal gene from the affected parent and one of the normal genes from the unaffected parent

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Offspring

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Offspring This child has inherited the normal gene from the affected parent and the other normal gene from the unaffected parent

Which children are affected by the disease? AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Which children are affected by the disease? Offspring

AUTOSOMAL DOMINANT INHERITANCE Parents Gametes Affected Affected Unaffected Unaffected

AUTOSOMAL DOMINANT INHERITANCE Each child of someone with an autosomal dominant disorder therefore has a 1/2 50% 50:50 chance of inheriting the gene alteration Affected Unaffected