Report of the chromosome 18 workshop

Abstract

At the first chromosome 18 workshop held at the 1997 World Congress on Psychiatric Genetics (WCPG) in Santa Fe, NM, several studies were presented that suggested the presence of a bipolar disorder (BP) as well as a schizophrenia (SZ) susceptibility locus on chromosome 18. Although the fact that several independent studies all pointed to a susceptibility locus (or loci) on chromosome 18, the observation that these studies identified nonoverlapping candidate regions was disappointing at least from the viewpoint of molecular genetics aiming at cloning the respective gene(s). Together, the data suggested four possible regions of considerable size that contained a susceptibility gene. At the 1998 WCPG chromosome 18 workshop in Bonn, Germany, less data were submitted and with the exception of a few studies, most data were nonsupportive or negative. Although some refinements were made to the previous candidate loci, overall the picture has not changed in that we are still confronted with the same four potential loci on chromosome 18 for BP and/or SZ, i.e., 18p11.2 and 18q12.1-q12.3 for BP and SZ, and 18q21-q22 and 18q23-qter for BP. So far, no other psychiatric phenotypes show evidence for a susceptibility locus on chromosome 18.

Pilot study for family-based association analysis of schizophrenia in a Korean population: Analysis for candidate genes positionally on chromosome 18q21

“…A wide range of studies suggest a genetic component to the inheritance of both of these psychotic disorders (Shih et al, 2004). Although, historically, bipolar disorder and schizophrenia were felt to be distinct illnesses, a slew of recent studies suggest that these disorders are genetically overlapping (Van Broeckhoven and Verheyen, 1999;Pulver et al, 2000;Siris, 2000;Bailer et al, 2002;Cardno et al, 2002;Potash et al, 2003;Walss-Bass et al, 2005). Previous studies conducted in the Costa Rican population have shown evidence of linkage disequilibrium between markers within the 18q21 region and both of these psychiatric phenotypes -severe bipolar disorder and schizophrenia (Escamilla et al, 2001;Walss-Bass et al, 2005).…”

Full-Genome Scan for Linkage in 50 Families Segregating the Bipolar Affective Disease Phenotype

“…Evidence for linkage to 21q (Straub et al 1994), 4p (Blackwood et al 1996), and 12q (Barden and Morissette 1999), implicated in single kindreds selected from larger family sets, has also been supported by the results of some studies Smyth et al 1997;Gurling et al 1998;Aita et al 1999;Craddock and Lendon 1999) but not by findings from the majority of independent follow-up studies. The results of a large number of studies of chromosomes 4, 12, 18, and 21 have recently been published (Curtis 1999;Detera-Wadleigh 1999;Kennedy et al 1999;Van Broeckhoven and Verheyen 1999).…”

Golli Myelin Basic Proteins Modulate Voltage-Operated Ca++ Influx and Development in Cortical and Hippocampal Neurons

“…There is evidence that genes in this region are involved in psychiatric and cognitive disorders [56, 57]. For example, a genome wide scan suggested the golli-MBP locus (18q23) is a susceptibility locus for bipolar disorder [58]. Several studies have shown changes in classic MBP gene expression in schizophrenia and bipolar disorder in different brain regions [59, 53, 55].…”