Association of the Type 2 Diabetes Mellitus Susceptibility Gene, TCF7L2, with Schizophrenia in an Arab-Israeli Family Sample

Many reports in different populations have demonstrated linkage of the 10q24–q26 region to schizophrenia, thus encouraging further analysis of this locus for detection of specific schizophrenia genes. Our group previously reported linkage of the 10q24–q26 region to schizophrenia in a unique, homogeneous sample of Arab-Israeli families with multiple schizophrenia-affected individuals, under a dominant model of inheritance. To further explore this candidate region and identify specific susceptibility variants within it, we performed re-analysis of the 10q24-26 genotype data, taken from our previous genome-wide association study (GWAS) (Alkelai et al, 2011). We analyzed 2089 SNPs in an extended sample of 57 Arab Israeli families (189 genotyped individuals), under the dominant model of inheritance, which best fits this locus according to previously performed MOD score analysis. We found significant association with schizophrenia of the TCF7L2 gene intronic SNP, rs12573128, (p = 7.01×10−6) and of the nearby intergenic SNP, rs1033772, (p = 6.59×10−6) which is positioned between TCF7L2 and HABP2. TCF7L2 is one of the best confirmed susceptibility genes for type 2 diabetes (T2D) among different ethnic groups, has a role in pancreatic beta cell function and may contribute to the comorbidity of schizophrenia and T2D. These preliminary results independently support previous findings regarding a possible role of TCF7L2 in susceptibility to schizophrenia, and strengthen the importance of integrating linkage analysis models of inheritance while performing association analyses in regions of interest. Further validation studies in additional populations are required

Nutrigenomics as strategy for neuronal health

Nutrigenomics through gene expression and epigenetic remodeling can program adult health. Diet during pregnancy and lactation (the first 1000 days of life) can modulate offspring’s epigenome leading to tissue specific variations during cell differentiation processes, and may define epigenetic marks associated with longterm effects on offspring neuronal health. Being epigenetics reversible, a healthy diet represents a fundamental opportunity, even after the first 1000 days of life, for maintaining cellular homeostasis. The positive impact of food (i.e. maternal milk, oily fish, fruit and vegetables, curcumin, tea) with its dietary flavonoids (i.e. sulforaphane, quercetin, lutein, resveratrol, carotenoids) and other bioactive compounds (i.e. docosahexanoic acid, melatonin etc.), will be reflected on chromatin structure modulation and DNA methylation which are associated with switching on/off of genes. An anti-inflammatory diet during early-life and across the whole life may represent a key strategy for influencing brain plasticity and for building an “epigenetic memory” useful in developing neuronal resilience against early-life stressors and to prevent age-related neurodegeneration