Autosomal Recessive Disease
Disease caused when an individual inherits a mutation(s) that may not cause disease unless both copies of a gene pair are mutated.
In an autosomal recessive disease, the affected person needs to have both copies of the gene altered in a similar way (one gene copy is inherited from each biological parent). These genes lie on one of 22 pairs of autosomal chromosomes [the non-sex chromosomes (not X or Y); see Autosome] that are inherited from biological parents. The double-inheritance of the same mutant gene occurs less frequently than inheritance of a dominant disease gene mutation (and there isn't necessarily an affected person in every generation), making it more difficult to identify recessive disease-causing genes.