disease, single gene

disease, single gene A hereditary disorder caused by a change (mutation) in a single gene. There are thousands of single-gene diseases, including achondroplasia, Huntington’s disease, cystic fibrosis, sickle cell anemia, Duchenne muscular dystrophy, and hemophilia. Single-gene diseases typically describe classic simple Mendelian patterns of inheritance (as autosomal dominant, autosomal recessive, and X-linked traits), compared to polygenic diseases, which follow more complex patterns of inheritance. See also disease, polygenic.