Open AccessHeterozygous inheritance of schizophrenia
Author(s) -
KARLSSON JON L.
Publication year - 1987
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1987.tb00269.x
Subject(s) - penetrance , biology , offspring , first degree relatives , dominance (genetics) , genetics , inheritance (genetic algorithm) , population , schizophrenia (object oriented programming) , heterozygote advantage , allele , demography , gene , family history , psychology , psychiatry , medicine , pregnancy , phenotype , sociology
K arlsson , J.L. 1987. Heterozygous inheritance of schizophrenia. — Hereditas 107: 59–64. Lund, Sweden. ISSN 0018–0661. Received October 28, 1986 Multigenerational data from Iceland give support to dominance with incomplete penetrance as the genetic mechanism for schizophrenia. Some kindreds show segregation into high and low rate branches, and the risk declines in a systematic fashion as relation to an index case becomes more distant. The risk in first‐degree relatives is about 15%, second‐degree 9%, third‐degree 6%, as compared to 3.5% in the general population. Since expression is influenced by the internal milieu, the rate is elevated in persons related to severely ill patients of those coming from multiple case families. Evidence from offspring of psychotic couples suggests that the mutant homozygotes are nonviable. Affected individuals are thus all heterozygous, but only about one‐fourth of gene carriers develops psychotic illness. The frequency of the gene is maintained high by a positive effect on creative thought processes in heterozygous carriers.