Transmission disequilibrium analysis of a triplet repeat within the hKCa3 gene using family trios with schizophrenia.
hKCa3 is a neuronal small conductance calcium-activated potassium channel which contains a polyglutamine tract, encoded by a polymorphic CAG repeat in the gene. Since an association between longer alleles of the CAG repeat and schizophrenia has been reported, we performed haplotype-based haplotype relative risk (HHRR) and transmission disequilibrium (TDT) in 97 family trios with schizophrenia from SW China. We found no evidence for an excess of longer CAG repeats in the patients, and the ETDT test was not significant for either allele-wise (P = 0.31) or genotype-wise analysis (P = 0.18). However, there was a deficit of transmission of the (CAG)20 repeat allele to affected offspring when this allele was considered individually by TDT (P = 0.012; not corrected for multiple testing). These data do not support a role for larger alleles at the hKCa3 locus in psychosis in Chinese subjects.
Li
T
T
Department of Psychological Medicine and Centre for Social, Genetic and Developmental Psychiatry, The Institute of Psychiatry, De Crespigny Park, Denmark Hill, SE5 8AF, United Kingdom.
Hu
X
X
Chandy
K G
KG
Fantino
E
E
Kalman
K
K
Gutman
G
G
Gargus
J J
JJ
Freeman
B
B
Murray
R M
RM
Dawson
E
E
Liu
X
X
Bruinvels
A T
AT
Sham
P C
PC
Collier
D A
DA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D002681:China; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D005260:Female; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000235:genetics*; D024681:Potassium Channels, Calcium-Activated; D012306:Risk; D012559:Schizophrenia / Q000235:genetics*; D051640:Small-Conductance Calcium-Activated Potassium Channels; D018911:Trinucleotide Repeats
C406328:KCNN3 protein, human; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D051640:Small-Conductance Calcium-Activated Potassium Channels