Autosomal inheritance describes the patterns of genetic transmission related to genes located on autosomal chromosomes. Accordingly, autosomal dominant or autosomal recessive inheritance patterns are based upon transmission of genes found on chromosomes other than the sex chromosomes. Autosomal inheritance patterns account for approximately half of genetic diseases and abnormalities.

All chromosomes found in human cells, except the X and Y sex chromosomes, are autosomes. Human cells carry 22 pairs of homologous autosomal chromosomes. Autosome pairs are numbered, largest to smallest, from 1 to 22. In normal human cells, one of the homologous chromosomes in each pair comes from the mother, the other is donated by the father. Homologous autosomal chromosomes contain similar, but not identical genes. Although normal homologous autosomes contain the same genes (e.g., the gene for a particular trait) each may carry a different form of the gene (allele).

Autosomal dominant inheritance occurs when an allele...