Missense mutation of WKL1 gene is not etiologic of schizophrenia in a selected pedigree set

Recently, a Leu309Met mutation in WKL1 (chromosome 22q13.33) was reported to co-segregate with periodic catatonia in 7 members of an extended pedigree (Meyer et al., 2001). Periodic catatonia is a familial subtype of schizophrenia where psychomotor disturbances are exhibited during acute psychotic outbursts. WKL1 encodes a putative non-selective cation channel expressed exclusively in the brain(Meyer et al., 2001). We screened WKL1 for etiologic mutations in 28 probands who were given a consensus diagnosis of schizophrenia and met at least one of these criteria: 1) were from multiplex catatonic schizophrenia families where at least two schizophrenic subjects were reported to display catatonic behavior at sometime during the course of their illness, or 2) were from multiplex schizophrenia families where in a genome scan for schizophrenia susceptibility loci, evidence for excess allele sharing among affected family members for markers in the 22q13 region was seen. Twenty-three SNPs in WKL1 were screened to identify single base changes. No missense mutations were detected in any of the 28 probands. Haploinsufficiency of WKL1 appears not to be relevant in the etiology of schizophrenia or the catatonic subtype of schizophrenia in this sample of 28 familial schizophrenics.