1Schizophr. Res. 2010 Dec 124: 192-9
PMID20889312
TitleA genome-wide meta-analysis identifies novel loci associated with schizophrenia and bipolar disorder.
Abstractschizophrenia and bipolar disorder both have strong inherited components. Recent studies have indicated that schizophrenia and bipolar disorder may share more than half of their genetic determinants. In this study, we performed a meta-analysis (combined analysis) for genome-wide association data of the Affymetrix Genome-Wide Human SNP array 6.0 to detect genetic variants influencing both schizophrenia and bipolar disorder using European-American samples (653 bipolar cases and 1034 controls, 1172 schizophrenia cases and 1379 controls). The best associated SNP rs11789399 was located at 9q33.1 (p=2.38 × 10(-6), 5.74 × 10(-4), and 5.56 × 10(-9), for schizophrenia, bipolar disorder and meta-analysis of schizophrenia and bipolar disorder, respectively), where one flanking gene, ASTN2 (220kb away) has been associated with attention deficit/hyperactivity disorder and schizophrenia. The next best SNP was rs12201676 located at 6q15 (p=2.67 × 10(-4), 2.12 × 10(-5), 3.88 × 10(-8) for schizophrenia, bipolar disorder and meta-analysis, respectively), near two flanking genes, GABRR1 and GABRR2 (15 and 17kb away, respectively). The third interesting SNP rs802568 was at 7q35 within CNTNAP2 (p=8.92 × 10(-4), 1.38 × 10(-5), and 1.62 × 10(-7) for schizophrenia, bipolar disorder and meta-analysis, respectively). Through meta-analysis, we found two additional associated genes NALCN (the top SNP is rs2044117, p=4.57 × 10(-7)) and NAP5 (the top SNP is rs10496702, p=7.15 × 10(-7)). Haplotype analyses of above five loci further supported the associations with schizophrenia and bipolar disorder. These results provide evidence of common genetic variants influencing schizophrenia and bipolar disorder. These findings will serve as a resource for replication in other populations to elucidate the potential role of these genetic variants in schizophrenia and bipolar disorder.
SCZ Keywordsschizophrenia, schizophrenic
2Psychiatry Res 2011 Feb 185: 450-2
PMID20674038
TitleLack of association of NALCN genetic variants with schizophrenia.
AbstractNALCN (sodium leak channel, non-selective) is located on chromosome 13q (suggested linkage region for schizophrenia). We analyzed 21 polymorphisms in 464 schizophrenia subjects, 220 controls subjects and 119 small nuclear families. We observed nominal association with rs9518320 and rs9518331, suggesting that NALCN is not related to schizophrenia risk.
SCZ Keywordsschizophrenia, schizophrenic
3Pharmacogenet. Genomics 2012 Nov 22: 807-11
PMID23047292
TitleAnalysis of treatment-resistant schizophrenia and 384 markers from candidate genes.
AbstractThe treatment of patients with schizophrenia who fail to respond to antipsychotics is a major challenge and the proportion of treatment-resistant patients is estimated to be 20 to 40%. There are few genetic association studies that have compared resistant versus non-resistant schizophrenic patients; however, many genetic association studies focusing on antipsychotic response have been published. This contribution investigates the genetics of treatment-resistant schizophrenia, testing 384 candidate gene loci related to the neurobiology of the disease. First, we identified a subgroup of treatment-resistant patients in a sample of 240 schizophrenia patients using the American Psychiatric Association criteria and then we genotyped all patients using a custom Illumina Bead Chip comprising of 384 single nucleotide polymorphisms. We screened all markers for nominal significance and for statistical significance after multiple-testing correction. The most significant single nucleotide polymorphism was the rs2152324 marker in the NALCN gene (P=0.004); however, after the FDR correction, the P-value was not significant. Our analysis of 384 markers across candidate genes did not indicate any robust association with treatment-resistant schizophrenia. However, this phenotype can be assessed retrospectively in cross-sectional studies and these preliminary results point out the importance of choosing alternative phenotypes in psychiatric pharmacogenetics.
SCZ Keywordsschizophrenia, schizophrenic
4Pharmacogenet. Genomics 2012 Nov 22: 807-11
PMID23047292
TitleAnalysis of treatment-resistant schizophrenia and 384 markers from candidate genes.
AbstractThe treatment of patients with schizophrenia who fail to respond to antipsychotics is a major challenge and the proportion of treatment-resistant patients is estimated to be 20 to 40%. There are few genetic association studies that have compared resistant versus non-resistant schizophrenic patients; however, many genetic association studies focusing on antipsychotic response have been published. This contribution investigates the genetics of treatment-resistant schizophrenia, testing 384 candidate gene loci related to the neurobiology of the disease. First, we identified a subgroup of treatment-resistant patients in a sample of 240 schizophrenia patients using the American Psychiatric Association criteria and then we genotyped all patients using a custom Illumina Bead Chip comprising of 384 single nucleotide polymorphisms. We screened all markers for nominal significance and for statistical significance after multiple-testing correction. The most significant single nucleotide polymorphism was the rs2152324 marker in the NALCN gene (P=0.004); however, after the FDR correction, the P-value was not significant. Our analysis of 384 markers across candidate genes did not indicate any robust association with treatment-resistant schizophrenia. However, this phenotype can be assessed retrospectively in cross-sectional studies and these preliminary results point out the importance of choosing alternative phenotypes in psychiatric pharmacogenetics.
SCZ Keywordsschizophrenia, schizophrenic
5Am. J. Hum. Genet. 2013 Oct 93: 721-6
PMID24075186
TitleMutations in NALCN cause an autosomal-recessive syndrome with severe hypotonia, speech impairment, and cognitive delay.
AbstractSodium leak channel, nonselective (NALCN) is a voltage-independent and cation-nonselective channel that is mainly responsible for the leaky sodium transport across neuronal membranes and controls neuronal excitability. Although NALCN variants have been conflictingly reported to be in linkage disequilibrium with schizophrenia and bipolar disorder, to our knowledge, no mutations have been reported to date for any inherited disorders. Using linkage, SNP-based homozygosity mapping, targeted sequencing, and confirmatory exome sequencing, we identified two mutations, one missense and one nonsense, in NALCN in two unrelated families. The mutations cause an autosomal-recessive syndrome characterized by subtle facial dysmorphism, variable degrees of hypotonia, speech impairment, chronic constipation, and intellectual disability. Furthermore, one of the families pursued preimplantation genetic diagnosis on the basis of the results from this study, and the mother recently delivered healthy twins, a boy and a girl, with no symptoms of hypotonia, which was present in all the affected children at birth. Hence, the two families we describe here represent instances of loss of function in human NALCN.
SCZ Keywordsschizophrenia, schizophrenic
6Front Cell Neurosci 2014 -1 8: 132
PMID24904279
TitleThe sodium leak channel, NALCN, in health and disease.
AbstractIon channels are crucial components of cellular excitability and are involved in many neurological diseases. This review focuses on the sodium leak, G protein-coupled receptors (GPCRs)-activated NALCN channel that is predominantly expressed in neurons where it regulates the resting membrane potential and neuronal excitability. NALCN is part of a complex that includes not only GPCRs, but also UNC-79, UNC-80, NLF-1 and src family of Tyrosine kinases (SFKs). There is growing evidence that the NALCN channelosome critically regulates its ion conduction. Both in mammals and invertebrates, animal models revealed an involvement in many processes such as locomotor behaviors, sensitivity to volatile anesthetics, and respiratory rhythms. There is also evidence that alteration in this NALCN channelosome can cause a wide variety of diseases. Indeed, mutations in the NALCN gene were identified in Infantile Neuroaxonal Dystrophy (INAD) patients, as well as in patients with an Autosomal Recessive Syndrome with severe hypotonia, speech impairment, and cognitive delay. Deletions in NALCN gene were also reported in diseases such as 13q syndrome. In addition, genes encoding NALCN, NLF- 1, UNC-79, and UNC-80 proteins may be susceptibility loci for several diseases including bipolar disorder, schizophrenia, Alzheimer's disease, autism, epilepsy, alcoholism, cardiac diseases and cancer. Although the physiological role of the NALCN channelosome is poorly understood, its involvement in human diseases should foster interest for drug development in the near future. Toward this goal, we review here the current knowledge on the NALCN channelosome in physiology and diseases.
SCZ Keywordsschizophrenia, schizophrenic