Analysis of the candidate genes responsible for non syndromic cleft lip and palate in Japanese people

In order to assess the association of alleles for candidate genes with non- syndromic cleft lip and palate, DNA samples from 43 Japanese patients were compared with those from 73 control subjects with respect to the genes enco ding transforming growth factor alpha (TGF alpha), TGF beta and gamma-amino butyric acid type A receptor beta 3 (GABRB3). The restriction fragment leng th polymorphisms of the 3'-non-coding region of the TGF alpha gene K-primer region were observed after digestion with NcoI and HinfI. Allele 4 was the most common among cases of cleft lip with or without cleft palate, whereas allele 2 was the most common among controls. A significant difference was found in this region between groups with cleft lip (with or without cleft p alate) and controls (chi(2) = 10.190; P = 0.017). Three alleles of the TGF beta 2 gene were tested, and allele 2 was the most common in both cases and controls. The proportion of allele 2 in the case group was greater than th at in the control group, showing a significant difference between cases of cleft lip (with or without cleft palate) and controls (chi(2) = 19.208; P < 0.0001). No significant differences in variants of TGF beta 3 or GABRB3 be tween case and control populations were observed. Thus it is concluded that TGF genes play a role in craniofacial development, and that alleles of TGF alpha or/and TGF beta 2 are associated with cleft lip and cleft palate in Japanese populations.