Lack of Association between LCT_rs140433552*CA>del Indel Polymorphism and Lactose Intolerance in a Southern Brazilian Population.

Background/aims: Polymorphisms in the enhancer of the lactase gene (LCT) are strongly associated with lactase persistence, but not always predictive of the phenotype. We investigated a possible association between the regulatory rs140433552*CA>del variant of LCT and lactose intolerance (LI).

Methods: We genotyped 122 individuals for rs140433552 and rs4988235 (-13910*C>T).

Results: Associations of rs140433552*CA>del with LI depend on -13910*C>T. Homozygous individuals for the C-CA haplotype, as well as C-CA+/C individuals, seem more likely to manifest LI (OR 3.33 [95% CI 1.32-8.35], p = 0.011, and OR 3.93 [95% CI 1.61-9.61], p = 0.003, respectively), while homozygous individuals for the T-CA haplotype seem more likely to be lactose tolerant (OR 0.04 [95% CI 0.002-0.70], p = 8 × 10-4).

Conclusions: rs140433552*CA>del is not independently associated with LI.