1Mov. Disord. 2007 Jul 22: 1358-61
PMID17469188
TitlePhenotypic variability of a distinct deletion in McLeod syndrome.
AbstractThe X-linked McLeod neuroacanthocytosis syndrome strongly resembles Huntington's disease and has been reported in various countries world-wide. Herein, we report two Chilean brothers with predominant psychiatric features at disease onset including schizophrenia-like psychosis and obsessive compulsive disorder. Molecular genetic analysis revealed a small deletion in the XK gene (938-942delCTCTA), which has been already described in a North American patient of Anglo-Saxon descent and a Japanese family, presenting with seizures, muscle atrophy or chorea yet absence of psychiatric features. These findings argue against a founder effect and indicate a profound phenotypic variability associated with the 938-942delCTCTA deletion. Our report supports the inclusion of McLeod syndrome in the differential diagnosis of Huntington's disease as well as acute psychosis in male subjects.
SCZ Keywordsschizophrenia
2Mol. Psychiatry 2009 Aug 14: 804-19
PMID18521090
TitleAssociation of the NPAS3 gene and five other loci with response to the antipsychotic iloperidone identified in a whole genome association study.
AbstractA whole genome association study was performed in a phase 3 clinical trial conducted to evaluate a novel antipsychotic, iloperidone, administered to treat patients with schizophrenia. Genotypes of 407 patients were analyzed for 334,563 single nucleotide polymorphisms (SNPs). SNPs associated with iloperidone efficacy were identified within the neuronal PAS domain protein 3 gene (NPAS3), close to a translocation breakpoint site previously observed in a family with schizophrenia. Five other loci were identified that include the XK, Kell blood group complex subunit-related family, member 4 gene (XKR4), the tenascin-R gene (TNR), the glutamate receptor, inotropic, AMPA 4 gene (GRIA4), the glial cell line-derived neurotrophic factor receptor-alpha2 gene (GFRA2), and the NUDT9P1 pseudogene located in the chromosomal region of the serotonin receptor 7 gene (HTR7). The study of these polymorphisms and genes may lead to a better understanding of the etiology of schizophrenia and of its treatment. These results provide new insight into response to iloperidone, developed with the ultimate goal of directing therapy to patients with the highest benefit-to-risk ratio.
SCZ Keywordsschizophrenia
3Neurosci. Res. 2011 Mar 69: 196-202
PMID21145924
TitleComprehensive analysis of the genes responsible for neuroacanthocytosis in mood disorder and schizophrenia.
AbstractNeuroacanthocytosis syndromes are mainly comprised of two diseases: chorea-acanthocytosis (ChAc) and McLeod syndrome (MLS). There is a high incidence of psychiatric disorders such as mood disorder and schizophrenia among neuroacanthocytosis patients. We hypothesized that neuroacanthocytosis-related-genes might be associated with susceptibility to these psychiatric disorders. We performed a comprehensive mutation screen of VPS13A and XK, the gene responsible for ChAc and MLS, respectively, in 85 mood disorder subjects and XK in 86 schizophrenia subjects and compared the variants to 100 or more control alleles. We also performed copy number variation (CNV) analysis in 72 mood disorder subjects and 86 schizophrenia subjects. We identified three non-synonymous, two synonymous and six intron variants in mood disorder subjects and a novel GAT triplet repeat polymorphism in VPS13A. By CNV analysis, we identified a heterozygous exon 60-61 deletion in VPS13A in one mood disorder subject. We identified one non-synonymous and one intron variant in mood disorder and schizophrenia subjects, respectively, in XK. The presence of a pathogenic mutation or a potentially functional variant in mood disorder or schizophrenia subjects suggests that neuroacanthocytosis-related-genes might be involved in the pathogenesis of these psychiatric disorders.
SCZ Keywordsschizophrenia
4Anim. Genet. 2014 Jun 45: 439-41
PMID24666329
TitleA polymorphism in XKR4 is significantly associated with serum prolactin concentrations in beef cows grazing tall fescue.
AbstractFescue toxicosis is a common syndrome of poor growth and reproductive performance of beef cattle grazing endophyte-infected tall fescue infected with Lolium arundinaceum Schreb. Together with decreased feed intake, decreased growth rates and tissue necrosis due to vasoconstriction, depressed circulating serum prolactin concentrations are typically observed in cattle afflicted with fescue toxicosis. Polymorphisms within the XK, Kell blood group complex subunit-related family, member 4 (XKR4) gene located on BTA14 have been previously reported to be associated with rump fat thickness, residual feed intake, average daily feed intake and average daily gain in cattle. Associations also have been reported between XKR4 genotype and effectiveness of the dopamine antagonist iloperidone as a treatment of schizophrenia in humans. Domperidone, a related dopamine antagonist, mediates effects of fescue toxicosis on livestock, including restoring depressed concentrations of prolactin. A mixed-breed population of 592 beef cattle grazing endophyte-infected tall fescue was used to examine the association between XKR4 genotype and circulating prolactin concentrations. The SNP rs42646708 was significantly (P = 0.0002) associated with serum prolactin concentrations and explained 2.45% of the phenotypic variation. Effect of genotype at the SNP was tested across five breeds, with significant associations within both Angus (P = 0.0275) and Simmental (P = 0.0224) breeds. These results suggest XKR4 may play a role in mediating the negative effects of fescue toxicosis, and polymorphisms within this gene may be useful markers for selection for genetic resistance to the debilitating effects of endophyte-infected tall fescue.
SCZ Keywordsschizophrenia