Genome-wide association study identifies genes that may contribute to risk for developing heroin addiction
Authors: Nielsen, David A.; Ji, Fei; Yuferov, Vadim; Ho, Ann; He, Chunsheng; Ott, Jurg; Kreek, Mary Jeanne
Objectives We have used genome-wide association studies to identify variants that are associated with vulnerability to develop heroin addiction. Methods DNA from 325 methadone stabilized, former severe heroin addicts and 250 control individuals were pooled by ethnicity (Caucasian and African-American) and analyzed using the Affymetrix GeneChip Mapping 100K Set. Genome-wide association tests were conducted. Results The strongest association with vulnerability to develop heroin addiction, with experiment-wise significance (P = 0.035), was found in Caucasians with the variant rs10494334, a variant in an unannotated region of the genome (1q23.3). In African Americans, the variant most significantly associated with the heroin addiction vulnerability was rs950302, found in the cytosolic dual specificity phosphatase 27 gene DUSP27 (point-wise P = 0.0079). Furthermore, analysis of the top 500 variants with the most significant associations (point-wise P <= 0.0036) in Caucasians showed that three of these variants are clustered in the regulating synaptic membrane exocytosis protein 2 gene RIMS2. Of the top 500 variants in African-Americans (point-wise P <= 0.0238), three variants are in the cardiomyopathy associated 3 gene CMYA3. Conclusion This study identifies new genes and variants that may increase an individual's vulnerability to develop heroin addiction. Psychiatr Genet 20:207-214 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
Rare Copy Number Variations in a Chinese Cohort of Autism Spectrum Disorder
FRONTIERS IN GENETICS
Authors: Fan, Yanjie; Du, Xiujuan; Liu, Xin; Wang, Lili; Li, Fei; Yu, Yongguo
Autism spectrum disorder (ASD) is heterogeneous in symptom and etiology. Rare copy number variations (CNVs) are important genetic factors contributing to ASD. Currently chromosomal microarray (CMA) detecting CNVs is recommended as a first-tier diagnostic assay, largely based on research in North America and Europe. The feature of rare CNVs has not been well characterized in ASD cohorts from non-European ancestry. In this study, high resolution CMA was utilized to investigate rare CNVs in a Chinese cohort of ASD (n = 401, including 177 mildly/moderately and 224 severely affected individuals), together with an ancestry-matched control cohort (n = 197). Diagnostic yield was about 4.2%, with 17 clinically significant CNVs identified in ASD individuals, of which 12 CNVs overlapped with recurrent autism risk loci or genes. Autosomal rare CNV burden analysis showed an over-representation of rare loss events in ASD cohort, whereas the rate of rare gain events correlated with the phenotypic severity. Further analysis showed rare losses disrupting genes highly intolerant of loss-of-function variants were enriched in the ASD cohort. Among these highly constrained genes disrupted by rare losses, RIMS2 is a promising candidate contributing to ASD risk. This pilot study evaluated clinical utility of CMA and the feature of rare CNVs in Chinese ASD, with candidate genes identified as potential risk factors.