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
Braz. j. med. biol. res
;
40(11): 1441-1446, Nov. 2007. ilus
Artículo
en Inglés
| LILACS
| ID: lil-464313
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.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Lactasa-Florizina Hidrolasa
/
Intolerancia a la Lactosa
/
Mutación
Tipo de estudio:
Estudio diagnóstico
/
Estudio observacional
Límite:
Adulto
/
Femenino
/
Humanos
/
Masculino
País/Región como asunto:
America del Sur
/
Brasil
Idioma:
Inglés
Revista:
Braz. j. med. biol. res
Asunto de la revista:
Biologia
/
Medicina
Año:
2007
Tipo del documento:
Artículo
/
Congreso y conferencia
/
Documento de proyecto
País de afiliación:
Brasil
Institución/País de afiliación:
Universidade Federal do Rio Grande do Sul/BR
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