The incidence of adult type hypolactasia in patients with irritable bowel syndrome.

Introduction: The incidence of lactose intolerance in irritable bowel syndrome (IBS) varies in the literature (27-72%). Primary adult lactase deficiency (adult type hypolactasia) is the most common type of primary enzyme deficiency. Complaints related to lactose intolerance may overlap with the symptoms of IBS. Aim: To assess the prevalence of primary hypolactasia in patients with IBS. Material and methods: The study included 56 patients with IBS diagnosed based on the Rome III criteria and 23 healthy people. All study participants completed a questionnaire on IBS symptoms and lactose intolerance, and they underwent a hydrogen breath test (HBT) with lactose. In the group of patients with positive results of HBT, the polymorphism C/T -13910 and G/A -22018 in the promoter of the LCT gene encoding lactase was determined. Results: Lactase deficiency was diagnosed in HBT in 34 (60.7%) patients with IBS and in the control group - in 10 (43.5%). Primary adult type hypolactasia was confirmed in 78.9% (n = 30; 79.3% in the study group; 77.8% in the control group). There were no statistically significant differences in the occurrence of LCT gene polymorphisms in particular IBS subtypes. Adult type hypolactasia was significantly more common in patients with severe than moderate and mild enzyme deficiency in HBT (p < 0.05). Conclusions: The incidence of lactase deficiency in IBS patients is not different from that found in healthy subjects. Nevertheless, irrespective of the IBS subtype, lactose intolerance may pose additional issues in patients with IBS and requires the targeted treatment.

[Birth-cohort analysis in adult-type hypolactasia]. / A felnottkori hypolactasia születésikohorsz-vizsgálata.

INTRODUCTION AND AIM: To assess the prevalence of lactase gene promoter C/T13910 phenotypes in patients with lactose intolerance symptoms and to analyze the birth-cohort phenomenon in lactose-intolerant patients. METHOD: 1266 patients consulted between 2010 and 2017 were enrolled. Five-year cohort periods of patients born before 1939 and after 1995 were defined and the prevalence of C/T13910 phenotypes was calculated. C/T13910 phenotypes were determined by polymerase chain reaction. RESULTS: The prevalence of the CC phenotype was 43.1%, TC was detected in 44.3% and TT in 12.6% of the cases. The prevalence of the CC phenotype showed a non-linear incremental increase in females, from 9.13% in those born before 1939 to 37.7% in those born after 1995. CONCLUSION: The prevalence of CC phenotype raised incrementally in females, suggesting a gender/hormonal influence. Orv Hetil. 2019; 160(14): 549-554.

Análisis de los polimorfismos europeos en el gen lactasa entre grupos étnicos del Caribe Colombiano / Analysis of the european polymorphisms in lactase gene between ethnic groups in the Colombian Caribbean / Análise dos polimorfismos europeus no gene lactasa entre os grupos etnicos do Caribe Colombiano

La prevalencia de hipolactasia tipo adulto está influenciada por la etnicidad y la geografía. Los genotipos CC y GG, de los SNPs C/T-13910 y G/A-22018, respectivamente determinan hipolactasia en ciertos grupos étnicos y países del mundo. El objetivo de este estudio fue analizar estos SNPs en muestras de los tres grupos étnicos que habitan el Caribe Colombiano. Trescientos sesenta y un sujetos, agrupados como afrodescendientes, indígenas y mestizos, fueron genotipificados usando PCR/RFLP. El análisis genético se hizo mediante Arlequin 3.11 y las frecuencias genotípicas fueron comparadas con Statgraphics Centurion XVI. Solamente el SNP C/T-13910 mostró equilibrio de Hardy- Weinberg y no hubo desequilibrio de ligamiento entre los SNPs estudiados. La frecuencia del genotipo CC-13910 fue 90% en afrodescendientes, 95% en indígenas y 80% en mestizos. En indígenas la frecuencia de GG-22018 fue 23% pero dicho genotipo no se halló en afrodescendientes y mestizos. El genotipo AA-22018 no se halló en indígenas. Ningún grupo presentó el genotipo TT-13910. Las frecuencias genotípicas fueron estadísticamente diferentes entre los grupos estudiados y las de los genotipos CC-13910 y GG-22018 no concordaron con las frecuencias fenotípicas reportadas en otros estudios. Los resultados sugieren que la posibilidad diagnóstica de hipolactasia mediante genotipificación de estos polimorfismos es escasa en el Caribe Colombiano.

The prevalence of adult-type hypolactasia is influenced by ethnicity and geography. The CC and GG genotypes of the SNPs C/T-13910 and G/A-22018, respectively indicate hypolactasia in certain ethnic groups worldwide. The aim of this study was to analyse these SNPs in samples of the three ethnic groups that inhabit the Colombian Caribbean. Three hundred and sixty-one subjects were genotyped using PCR/RFLP. These subjects were grouped as being of African descent, Indigenous and Mestizo. The genetic analysis was performed through Arlequin 3.11 and genotype frequencies were compared with Statgraphics Centurion XVI. Only SNP C/T-13910 showed Hardy-Weinberg equilibrium and there was no linkage disequilibrium between the SNPs. The frequency of CC-13910 was 90% in Afro-descendant, 95% in indigenous people and 80% in mestizos.The frequency of GG-22018 was 23% in indigenous people, but this genotype was not present in afro-descendants and Mestizos. The indigenous people did not have AA-22018, and none of the groups had TT-13910. The genotype frequencies were statistically different among the groups studied and the frequencies of CC-13910 and GG-22018 were not in concordance with the phenotype frequencies reported in other papers. The results suggest that diagnostic possibility of hypolactasia by genotyping of those polymorphisms in the Colombian Caribbean population is scarce.

A prevalência da hipolactasia primária tipo adulto é influenciada pela etnicidade e a geografia. Os genótipos CC e GG, dos SNPs C/T-13910 e G/A-22018, respectivamente, são determinantes da hipolactasia em alguns grupos étnicos e países do mundo. O objetivo do presente estudo foi analisar estes SNPs em amostras dos três grupos étnicos do Caribe Colombiano. Trezentas e sessenta e uma pessoas reunidas como afrodescendentes, indígenas e mestiços foram genotipificadas utilizando PCR/RFLP. A análise genética foi realizada usando o software Arlequin 3.11 e as frequências genotípicas foram comparadas com o Statgraphics Centurion XVI. Somente o SNP C/T-13910 mostrou equilíbrio de Hardy-Weinberg e não houve desequilíbrio de ligamento entre os SNPs estudados. A frequência do genótipo CC-13910 foi de 90% para afrodescendentes, 95% para indígenas e 80% em mestiços. Nos indígenas a frequência de GG-22018 foi de 23% mas tal genótipo não esteve presente na população de afrodescendentes e mestiços. O genótipo AA-22018 não foi encontrado em indígenas. Nenhum grupo apresentou o genótipo TT-13910. As frequências genotípicas foram estatisticamente diferentes entre os grupos avaliados e as dos genótipos CC-13910 e GG-22018, não concordaram com as frequências fenotípicas relatados em outros estudos. Os resultados sugerem que a possibilidade diagnóstica de hipolactasia através de genotipificação destes polimorfismos é escassa em populações do Caribe Colombiano.

Análisis de los polimorfismos europeos en el gen Lactasa entre grupos étnicos del Caribe Colombiano / Analysis of the European polymorphisms in lactase gene between ethnic groups in the Colombian Caribbean / Análise dos polimorfismos europeus no gene lactasa entre os grupos etnicos do Caribe Colombiano

La prevalencia de hipolactasia tipo adulto está influenciada por la etnicidad y la geografía. Los genotipos CC y GG, de los SNPs C/T-13910 y G/A-22018, respectivamente determinan hipolactasia en ciertos grupos étnicos y países del mundo. El objetivo de este estudio fue analizar estos SNPs en muestras de los tres grupos étnicos que habitan el Caribe Colombiano. Trescientos sesenta y un sujetos, agrupados como afrodescendientes, indígenas y mestizos, fueron genotipificados usando PCR/RFLP. El análisis genético se hizo mediante Arlequin 3.11 y las frecuencias genotípicas fueron comparadas con Statgraphics Centurion XVI. Solamente el SNP C/T-13910 mostró equilibrio de Hardy- Weinberg y no hubo desequilibrio de ligamiento entre los SNPs estudiados. La frecuencia del genotipo CC-13910 fue 90% en afrodescendientes, 95% en indígenas y 80% en mestizos. En indígenas la frecuencia de GG-22018 fue 23% pero dicho genotipo no se halló en afrodescendientes y mestizos. El genotipo AA-22018 no se halló en indígenas. Ningún grupo presentó el genotipo TT-13910. Las frecuencias genotípicas fueron estadísticamente diferentes entre los grupos estudiados y las de los genotipos CC-13910 y GG-22018 no concordaron con las frecuencias fenotípicas reportadas en otros estudios. Los resultados sugieren que la posibilidad diagnóstica de hipolactasia mediante genotipificación de estos polimorfismos es escasa en el Caribe Colombiano.(AU)

The prevalence of adult-type hypolactasia is influenced by ethnicity and geography. The CC and GG genotypes of the SNPs C/T-13910 and G/A-22018, respectively indicate hypolactasia in certain ethnic groups worldwide. The aim of this study was to analyse these SNPs in samples of the three ethnic groups that inhabit the Colombian Caribbean. Three hundred and sixty-one subjects were genotyped using PCR/RFLP. These subjects were grouped as being of African descent, Indigenous and Mestizo. The genetic analysis was performed through Arlequin 3.11 and genotype frequencies were compared with Statgraphics Centurion XVI. Only SNP C/T-13910 showed Hardy-Weinberg equilibrium and there was no linkage disequilibrium between the SNPs. The frequency of CC-13910 was 90% in Afro-descendant, 95% in indigenous people and 80% in mestizos.The frequency of GG-22018 was 23% in indigenous people, but this genotype was not present in afro-descendants and Mestizos. The indigenous people did not have AA-22018, and none of the groups had TT-13910. The genotype frequencies were statistically different among the groups studied and the frequencies of CC-13910 and GG-22018 were not in concordance with the phenotype frequencies reported in other papers. The results suggest that diagnostic possibility of hypolactasia by genotyping of those polymorphisms in the Colombian Caribbean population is scarce.(AU)

A prevalÛncia da hipolactasia primária tipo adulto é influenciada pela etnicidade e a geografia. Os genótipos CC e GG, dos SNPs C/T-13910 e G/A-22018, respectivamente, sÒo determinantes da hipolactasia em alguns grupos étnicos e países do mundo. O objetivo do presente estudo foi analisar estes SNPs em amostras dos trÛs grupos étnicos do Caribe Colombiano. Trezentas e sessenta e uma pessoas reunidas como afrodescendentes, indígenas e mestiþos foram genotipificadas utilizando PCR/RFLP. A análise genética foi realizada usando o software Arlequin 3.11 e as frequÛncias genotípicas foram comparadas com o Statgraphics Centurion XVI. Somente o SNP C/T-13910 mostrou equilíbrio de Hardy-Weinberg e nÒo houve desequilíbrio de ligamento entre os SNPs estudados. A frequÛncia do genótipo CC-13910 foi de 90% para afrodescendentes, 95% para indígenas e 80% em mestiþos. Nos indígenas a frequÛncia de GG-22018 foi de 23% mas tal genótipo nÒo esteve presente na populaþÒo de afrodescendentes e mestiþos. O genótipo AA-22018 nÒo foi encontrado em indígenas. Nenhum grupo apresentou o genótipo TT-13910. As frequÛncias genotípicas foram estatisticamente diferentes entre os grupos avaliados e as dos genótipos CC-13910 e GG-22018, nÒo concordaram com as frequÛncias fenotípicas relatados em outros estudos. Os resultados sugerem que a possibilidade diagnóstica de hipolactasia através de genotipificaþÒo destes polimorfismos é escassa em populaþ§es do Caribe Colombiano.(AU)

The C/C_13910 and G/G_22018 Genotypes for Adult-type Hypolactasia are not Associated with Inflammatory Bowel Disease.

BACKGROUND: Lactose intolerance with adult-onset is due to the inadequate enzymatic activity of lactase-phlorizin hydrolase (LPH). It is frequently seen in patients with Crohn disease, but the mechanism remains to be elucidated. Two DNA genotypes, C/C_13910 and G/G_22018, located upstream from the LCT locus, the gene encoding for LPH, were recently identified as representing genetic markers for lactose intolerance. We utilized these two DNA genotypes to study their role in inflammatory bowel disease. METHODS: We investigated the prevalence of these two DNA variants using specific restriction enzyme digest assays in 166 patients with Crohn disease, in 120 healthy first-degree relatives of Crohn disease patients, in 63 patients with ulcerative colitis and in 187 healthy individuals. RESULTS: The analysis revealed a frequency of 21.4% of the 2 genotypes for adult-type hypolactasia in our studied German cohort of healthy individuals, which is higher than previously reported (15%) based on the hydrogen (H2) breath test. This might indicate a higher sensitivity of genotyping, but it has to be confirmed in larger cohorts. No significant difference was detectable in the frequency of the C/C_13910 and G/G_22018 genotypes in patients with Crohn Disease (C/C_13910: 21.7%; G/G_22018: 22.3%) compared to first-degree relatives (C/C_13910: 21.7%; G/G_22018: 20.8%), patients with ulcerative colitis (C/C_13910: 20.3%; G/G_22018: 20.3%) and healthy individuals (C/C_13910: 21.4%; G/G_22018: 21.4%). CONCLUSIONS: The C/C_13910 and G/G_22018 genotype of adult-type hypolactasia is not associated with susceptibility to the pathogenesis of Crohn disease and ulcerative colitis.