No association between polymorphisms in the FACL4 (fatty acid-CoA ligase 4) gene and nonspecific mental retardation in Qin-Ba mountain region of China.

Mental retardation (MR) is a common form of cognitive impairment among children. The underlying causes of mental retardation are extremely heterogeneous and include significant genetic factors. Long chain fatty acid-CoA ligase 4 is the first gene shown to be involved in mental retardation and fatty-acid metabolism. FACL4 gene mutations in three Italian MR pedigrees have been reported as causing non-specific mental retardation. To investigate the possible genetic contribution of the FACL4 gene to non-specific mental retardation children of the Qin-Ba mountain region in China we performed an association study of 556 subjects (118 NSMR, 116 borderline NSMR, and 322 controls) from the Han children of northwestern China using five common SNPs (rs5943427, rs12856122, rs5943418, rs7886473, and rs10126612) in the gene. No significant differences of genotypes and alleles frequencies from each single SNP between NSMR and controls were observed. Pairwise linkage disequilibrium analysis showed that four SNPs rs5943427, rs12856122, rs5943418, and rs7886473 were in strong linkage disequilibrium; therefore, a haplotype analysis was performed. However, there were no any significant differences in haplotype distributions between cases and controls. In conclusion, we have found no evidence for the FACL4 gene conferring susceptibility on non-specific mental retardation children of the Qin-Ba mountain region in China.