Cauchi et al. (2007) investigated the association between the TCF7L2 rs7903146 polymorphism and T2D in Moroccans (406 normoglycemic individuals and 504 T2D subjects) and in white Austrians. The allelic odds ratios (ORs) for T2D were 1.56 and 1.52 in Moroccans and Austrians, respectively. No heterogeneity was found between these two different populations by Woolf test. Later, Cauchi et al. (2008) included this study group into a larger analysis to validate possible markers that could be highly associated with type 2 diabetes (T2D) in other European and non-European populations. The T2D risk increased strongly when risk alleles, including the T2D-associated TCF7L2 rs7903146 SNP, were combined. Cauchi et al. (2008) concluded that TCF7L2, SLC30A8, HHEX, CDKAL1, IGFBP2, and CDKN2A/CDKN2B genes strongly associate with T2D in French individuals, and mostly in populations of Central European descent, but not in Moroccan subjects.

A study by Alsmadi et al. (2008) was set to determine the role of two variants of the TCF7L2 gene in Arabs in the context of type 2 diabetes (T2D); these variants are rs7903146 and rs12255372. The latter variants have been strongly associated with T2D risk in many populations around the world. Saudi T2D patients (522 individuals), and controls (346 individuals) aged over 60, with fasting plasma glucose < 7 mmol/L were included in a case-control association study. The results indicated weak or no association of T2D in Arabs with the abovementioned TCF7L2 variants.