An association study between polymorphisms of L1CAM gene and schizophreniain a Japanese sample

L1CAM, a neural cell adhesion molecule, plays an important role in the deve lopment of the central nervous system. The human L1CAM gene is located in X q28. Mutations in the gene are responsible for a wide spectrum of neurologi cal abnormalities and mental retardation. Schizophrenia may result from ear ly neurodevelopmental abnormalities. We screened 30 male and 30 female schi zophrenic patients for their genomic sequence of the L1CAM gene in order to determine the DNA sequence variations. Three novel variations located in e xon 18 (10564 G > A, GG/AA at codon 758), intron 11 (8575 A > C), and intro n 25 (13504 C > T) were detected. An association study of the identified po lymorphisms was then performed in a Japanese sample of 152 male and 115 fem ale patients with schizophrenia and 121 male and 114 female control subject s. A statistically significant increase in the count of the 13504 T-allele was observed in the male patients, compared to the male controls, with no d ifferences in the variations of exon 18 or intron 11. There was no statisti cally significant change in the distribution of allele or genotype of any v ariations in the female schizophrenics, in comparison with the female contr ols. These results suggest that the polymorphism in intron 25 plays a role in the genetic predisposition of male schizophrenia in the Japanese sample, Am. J. Med. Genet. (Neuropsychiatr. Genet.) 105: 99-104, 2001. (C) 2001 Wi ley-Liss, Inc.