From single-SNP to wide-locus: genome-wide association studies identifying functionally related genes and intragenic regions in small sample studies.

Background: Genome-wide association studies (GWAS) have had limited success when applied to complex diseases. Analyzing SNPs individually requires several large studies to integrate the often divergent results. In the presence of epistasis, multivariate approaches based on the linear model (including stepwise logistic regression) often have low sensitivity and generate an abundance of artifacts.

Non-synonymous variants in the AMACR gene are associated with schizophrenia.

Background: The AMACR gene is located in the schizophrenia susceptibility locus on chromosome 5p13, previously identified in a large Puerto Rican pedigree of Spanish origin. The AMACR-encoded protein is an enzyme involved in the metabolism of branched-chain fatty and bile acids. The enzyme deficiency causes structural and functional brain changes, and disturbances in fatty acid and oxidative phosphorylation pathways observed in individuals with schizophrenia.

Mutation analysis of the C1QTNF3 gene in patients with schizophrenia.

We previously identified a small region on chromosome 5p13 related to schizophrenia in a Puerto Rican pedigree. We screened one of the positional candidate genes, C1QTNF3, for mutations in affected family members. The direct sequencing identified 10 sequence variants, including five shared by all affected family members.

Polyspike and waves do not predict generalized tonic-clonic seizures in childhood absence epilepsy.

About 40% of children with childhood absence epilepsy develop generalized tonic-clonic seizures. It is commonly held that polyspike-wave pattern on the electroencephalogram (EEG) can predict this development of generalized tonic-clonic seizures. However, there is no firm evidence in support of this proposition.