Karyotype analysis of 161 unrelated schizophrenics: no increased rates of X chromosome mosaicism or inv(9), using ethnically matched and age-stratified controls
T. Toyota et al., Karyotype analysis of 161 unrelated schizophrenics: no increased rates of X chromosome mosaicism or inv(9), using ethnically matched and age-stratified controls, SCHIZOPHR R, 52(3), 2001, pp. 171-179
Chromosomal aberrations have long been studied in an effort to identify sus
ceptibility genes in schizophrenia. The two most frequently detected abnorm
alities are X chromosome mosaicism in female patients and pericentric inver
sions of chromosome 9 [inv(9)]. Chromosome X aneuploidies are known to be a
ge dependent but differences due to ethnicity remain undetermined. ln the c
ase of inv(9). its prevalence in the general population varies with ethnici
ty. To evaluate the importance of these karyotypic changes in schizophrenia
, cytogenetic analysis was performed on 161 unrelated schizophrenics of Jap
anese origin. We observed an increase in the incidence of X chromosome mosa
icism in female schizophrenics with age. However, when compared with age ma
tched female controls (92 individuals), no significant differences between
patient and control samples were detected. Moreover, this study showed that
there is no significant difference in the incidence of X chromosome loss b
etween Japanese and Caucasian populations. The four cases with inv(9) (2.5%
) detected in this study, did not differ significantly from the reported in
cidence of between 1.7 and 2.1 % seen in the general Japanese population. W
e also observed a small number of additional karyotypic changes, none of wh
ich were recurrent. This is the first report to examine the comparative rat
es of X mosaicism in female schizophrenics and age matched controls. (C) 20
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