title: Is vitamin D hypothesis for schizophrenia valid? Independent segregation of psychosis in a family with vitamin-D-dependent rickets type IIA.
abstract: The vitamin D hypothesis of schizophrenia is a recent concept bringing together old observations on environmental risk factors and new findings on the neurodevelopmental effects of vitamin D. Candidate genes related to the vitamin D endocrine system have not yet been fully explored for this purpose. The coexistence of vitamin-D-dependent-rickets type II with alopecia (VDDR IIA) and different forms of psychosis in the same inbred family has provided us with an opportunity to investigate the presumed relationship between vitamin D deficiency and psychosis. Psychiatric examination and molecular genetic studies were performed in this family overloaded with psychotic disorders and VDDR IIA. Forty members were evaluated in order to describe their phenotypic features. The family was tested for a linkage to the chromosome 12q12-q14 region where the vitamin D receptor (VDR) gene is located. Psychosis was the common phenotype in the 18 psychiatrically affected members. Pedigree analysis did not show a cosegregation of psychosis and rickets. Lod scores were not significant to prove a linkage between psychosis and VDR locus. The authors concluded that (1) the neurodevelopmental consequences of vitamin D deficiency do not play a causative role in psychotic disorders, (2) these two syndromes are inherited independently, and (3) vitamin D deficiency does not act as a risk factor in subjects susceptible to psychosis.
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Hacettepe University, 06100 Sihhiye, Ankara, Turkey. ozers@hacettepe.edu.tr
authors.forename: Suzan
authors.initials: S
authors.lastname: Ozer
authors.forename: Aylin
authors.initials: A
authors.lastname: Uluşahin
authors.forename: Semra
authors.initials: S
authors.lastname: Ulusoy
authors.forename: Hamza
authors.initials: H
authors.lastname: Okur
authors.forename: Turgay
authors.initials: T
authors.lastname: Coşkun
authors.forename: Timur
authors.initials: T
authors.lastname: Tuncali
authors.forename: Ahmet
authors.initials: A
authors.lastname: Göğüş
authors.forename: A Nurten
authors.initials: AN
authors.lastname: Akarsu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000505:Alopecia / Q000209:etiology; D002881:Chromosomes, Human, Pair 12; D005192:Family Health; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010375:Pedigree; D010641:Phenotype; D011618:Psychotic Disorders / Q000209:etiology* / Q000235:genetics; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism; D012279:Rickets / Q000209:etiology* / Q000235:genetics; D012559:Schizophrenia / Q000209:etiology* / Q000235:genetics; D014808:Vitamin D Deficiency / Q000150:complications* / Q000235:genetics
chemical_list: D018167:Receptors, Calcitriol