Correlation between lactose absorption and the C/T-13910 and G/A-22018 mutations of the lactase-phlorizin hydrolase (LCT) gene in adult-type hypolactasia.

Abstract	The C/T-13910 mutation is the major factor responsible for the persistence of the lactase-phlorizin hydrolase (LCT) gene expression. Mutation G/A-22018 appears to be only in co-segregation with C/T-13910. The objective of the present study was to assess the presence of these two mutations in Brazilian individuals with and without lactose malabsorption diagnosed by the hydrogen breath test (HBT). Ten milk-tolerant and 10 milk-intolerant individuals underwent the HBT after oral ingestion of 50 g lactose (equivalent to 1 L of milk). Analyses for C/T-13910 and G/A-22018 mutations were performed using a PCR-based method. Primers were designed for this study based on the GenBank sequence. The CT/GA, CT/AA, and TT/AA genotypes (lactase persistence) were found in 10 individuals with negative HBT. The CC/GG genotype (lactase non-persistence) was found in 10 individuals, 9 of them with positive HBT results. There was a significant agreement between the presence of mutations in the LCT gene promoter and HBT results (kappa = -0.9, P < 0.001). The CT/AA genotype has not been described previously and seems to be related to lactase persistence. The present study showed a significant agreement between the occurrence of mutations G/A-22018 and C/T-13910 and lactose absorption in Brazilian subjects, suggesting that the molecular test used here could be proposed for the laboratory diagnosis of adult-type primary hypolactasia.
Authors	A C Bulhões, H A S Goldani, F S Oliveira, U S Matte, R B Mazzuca, T R Silveira
Journal	Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas (Braz J Med Biol Res) Vol. 40 Issue 11 Pg. 1441-6 (Nov 2007) ISSN: 1414-431X [Electronic] Brazil
PMID	17934640 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
Chemical References	Hydrogen Lactase-Phlorizin Hydrolase
Topics	Adult Brazil Breath Tests (methods) Case-Control Studies Female Genotype Humans Hydrogen (analysis) Lactase-Phlorizin Hydrolase (genetics) Lactose Intolerance (diagnosis, enzymology, genetics) Male Middle Aged Mutation (genetics) Polymerase Chain Reaction

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.

Realize the full power of the drug-disease research graph!