Topic summary
Autosomal

Extracted from the Wikipedia article Autosome.
Autosomal genetic disorders
Autosomal genetic disorders can arise due to a number of causes, some of the most common being nondisjunction in parental germ cells or Mendelian inheritance of deleterious alleles from parents. Autosomal genetic disorders which exhibit Mendelian inheritance can be inherited either in an autosomal dominant or recessive fashion. These disorders manifest in and are passed on by either sex with equal frequency. Autosomal dominant disorders are often present in both parent and child, as the child needs to inherit only one copy of the deleterious allele to manifest the disease. Autosomal recessive diseases, however, require two copies of the deleterious allele for the disease to manifest. Because it is possible to possess one copy of a deleterious allele without presenting a disease phenotype, two phenotypically normal parents can have a child with the disease if both parents are carriers (also known as heterozygotes) for the condition.