The American Psychiatric Association (APA) has updated its Privacy Policy and Terms of Use, including with new information specifically addressed to individuals in the European Economic Area. As described in the Privacy Policy and Terms of Use, this website utilizes cookies, including for the purpose of offering an optimal online experience and services tailored to your preferences.

Please read the entire Privacy Policy and Terms of Use. By closing this message, browsing this website, continuing the navigation, or otherwise continuing to use the APA's websites, you confirm that you understand and accept the terms of the Privacy Policy and Terms of Use, including the utilization of cookies.

×
No Access

Evidence for a schizophrenia vulnerability locus on chromosome 8p in the Irish Study of High-Density Schizophrenia Families

Published Online:https://doi.org/10.1176/ajp.153.12.1534

OBJECTIVE: This study was an attempt to replicate evidence for a vulnerability locus for schizophrenia and associated disorders in the 8p22-21 region reported by Pulver and colleagues. METHOD: The linkage sample of the Irish Study of High-Density Schizophrenia Families consists of 265 multiplex families containing 1,408 individuals. Fifteen markers covering 30 centimorgans on chromosome 8p were tested. Three statistical methods were used: two-point and multipoint heterogeneity lod scores and a multipoint nonparametric test. RESULTS: According to two-point heterogeneity lod scores, the strongest evidence for linkage was found for markers D8S1731 (maximum lod score = 2.00), D8S1715 (maximum lod score = 2.52), and D8S133 (maximum lod score = 2.08) by assuming a phenotypic definition of all psychiatric illness and a range of genetic models. According to multipoint heterogeneity lod scores, the strongest evidence for linkage (maximum lod score = 2.34), found by using a dominant genetic model and a broad definition of the schizophrenia spectrum, extended over a 10-cM region between markers D8S1715 and D8S1739. Multipoint nonparametric linkage found the strongest evidence (maximum z = 2.51) over a broader region when either a diagnosis of core schizophrenia or a narrow definition of the schizophrenia spectrum was used. This putative vulnerability locus was segregating in 10%-25% of the families studied. CONCLUSIONS: This study supports the existence of a vulnerability locus for schizophrenia on chromosome 8p. In this sample, this locus appears to influence the risk of illness in only a modest proportion of families and predisposes to a range of schizophrenia spectrum and possibly nonspectrum disorders.

Access content

To read the fulltext, please use one of the options below to sign in or purchase access.