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

Bulhões, Andréia Cristina da Silva; Goldani, Helena Ayako Sueno; Oliveira, Fernanda dos Santos de; Matte, Ursula da Silveira; Mazzuca, Rafael Bueno; Silveira, Themis Reverbel da

doi:10.1590/s0100-879x2007001100004

Cited by 40 publications

(45 citation statements)

References 22 publications

(30 reference statements)

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“…This is not the case for African Caribbean Colombians, because the blacks brought as slaves from Africa during the colonial period came mainly from Western Africa where the -13910*T allele is scarce (18,29) . The importance of the ethnic origin, when doing genotype-phenotype correlation studies is evident with the results recently published in Brazil by Bulhões et al (3) and Mattar et al (15) who reported perfect correlation between the SNP C/T -13910 and lactose digestion. They got this result because the subjects in their study were Brazilians of Caucasian descendence.…”

Section: Discussionmentioning

confidence: 69%

Diagnosis of adult-type hypolactasia/lactase persistence: genotyping of single nucleotide polymorphism (SNP C/T-13910) is not consistent with breath test in Colombian Caribbean population

Torres

Prieto

Camacho

et al. 2012

Arq. Gastroenterol.

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-Context -Genotyping of single nucleotide polymorphism (SNP C/T -13910 ) located upstream of the lactase gene is used to determine adult-type hypolactasia/lactase persistence in North-European Caucasian subjects. The applicability of this polymorphism has been studied by comparing it with the standard diagnostic methods in different populations. Objective -To compare the lactose hydrogen breath test with the genetic test in a sample of the Colombian Caribbean population. Methods -Lactose hydrogen breath test and genotyping of SNP C/T -13910 were applied to 128 healthy individuals (mean age 35 ± 1). A positive lactose hydrogen breath test was indicative of hypolactasia. Genotyping was done using polymerase chain reaction/restriction fragment length polymorphism. The kappa index was used to establish agreement between the two methods. Results -Seventy-six subjects (59%) were lactose-maldigesters (hypolactasia) and 52 subjects (41%) were lactose-digesters (lactase persistence). The frequencies of the CC, CT and TT genotypes were 80%, 20% and 0%, respectively. Genotyping had 97% sensitivity and 46% specificity. The kappa index = 0.473 indicates moderate agreement between the genotyping of SNP C/T -13910 and the lactose hydrogen breath test. Conclusion -The moderate agreement indicates that the genotyping of the SNP C/T -13910 is not applicable to determine adult-type hypolactasia/lactase persistence in the population participating in this study.

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“…It is estimated that 75% of adults worldwide show some decrease in lactase activity (hypolactasia), resulting in lactose intolerance still during adulthood. The phenomenon "lactose intolerance" is mainly found in African, Asian, South American and South European regions (Bulhões et al, 2007). Unfortunately, this frequently occurring of lactase activity deficiency hampers a broader application of whey for nutrition of mankind.…”

Section: General: the Need For Sustainable Utilization Of Wheymentioning

confidence: 99%

Whey Lactose as a Raw Material for Microbial Production of Biodegradable Polyesters

Koller¹,

Salerno²,

Muhr³

et al. 2012

Polyester

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“…Lactose waste increases biochemical and chemical oxygen demand (BOD and COD) which is in contrast with legal standards for wastewater (Cuartas-Uribe et al, 2009). In addition, lactose, as a disaccharide, is scarcely digestible for about 75% of adults worldwide due to lack of β-galactosidase enzyme in their body (Sieber et al, 1997;Bulhões et al, 2007). Furthermore, a high amount of lactose in dairy products like ice cream, condensed milk, etc., leads to an undesirable grainy texture.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of lactose hydrolysis and separation in cstr-uf membrane reactor

Namvar-Mahboub

Pakizeh

2012

Braz. J. Chem. Eng.

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-In this study, the effect of processing conditions on the performance of continuous stirred tankultrafiltration (CSTR-UF) in dead-end mode was investigated. An UF membrane with a molecular weight cutoff of 3 kDa made of regenerated cellulose material was used to separate enzyme from products. The effect of operating pressure ranging between 2 and 5 bar and time on the performance of the CSTR-UF system was studied. The experiments were performed with a 0.139 molar aqueous solution of lactose as feed. According to the experimental data, the lactose concentration in the permeate decreased with time due to concentration polarization and hydrolysis. It was found that the rejection factor of lactose increases from 33 to 77% with time from 5 to 85 min. Permeation flux of the membrane was evaluated in terms of pure water flux (PWF) and lactose aqueous solution. Results showed that a high operating pressure led to a high permeation flux for both mentioned cases. Also, adding lactose and enzyme to pure water caused a reduction of the permeation flux due to concentration polarization.

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“…[1][2][3][4] The frequency of decreased lactase activity ranges from 5% in northern Europe, through 71% in Sicily, to more than 90% in some African and Asian countries. 5 Previously, lactase deficiency was reported to be common among black South Africans (78%). 6 …”

Section: Introductionmentioning

confidence: 99%

Understanding lactose intolerance and the dietary management thereof

Labuschagne

Lombard

2012

South African Family Practice

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“…Os indivíduos com o genótipo CC apresentaram sintomas de intolerância à lactose, e aqueles com os genótipos CT e TT toleraram a lactose 14 , confirmando os achados publicados em 1973 por Sahi et al de que a intolerância à lactose primária do adulto é traço recessivo. 15 Estudos posteriores no Brasil 16,17,18 e em outros países [19][20][21][22][23][24][25][26] confirmaram a associação desse polimorfismo com a intolerância e tolerância à lactose, exceto na África. 27,28 Essa região LCT-13910C>T funcionou in vitro como elemento cis capaz de aumentar diferentemente a atividade de transcrição do promotor do gene da lactase 29 e se associou significantemente com maior expressão de RNAm do gene LCT na mucosa intestinal dos indivíduos com alelo de persistência da lactase, LCT-13910C>T e LCT-22018G>A, em relação aos que têm genótipo de hipolactasia, sugerindo que a ação seja em nível de regulação de transcrição do gene LCT 30 .…”

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Intolerância à lactose: mudança de paradigmas com a biologia molecular

Mattar

Mazo

2010

Rev. Assoc. Med. Bras.

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ResumoNa maioria dos mamíferos a atividade da enzima lactase diminui na parede intestinal após o desmame, caracterizando a hipolactasia primária que provoca sintomas de intolerância à lactose. A intensidade dos sintomas de distensão, flatulência, dor abdominal e diarreia variam, dependendo da quantidade de lactose ingerida, e aumentam com o passar da idade. A hipolactasia é determinada geneticamente, porém uma mutação ocorreu para que fizesse parte da humanidade tolerar o leite na idade adulta. O diagnóstico é feito por teste de tolerância, empregando a lactose como desafio. Com a descoberta dos finlandeses do polimorfismo associado com a persistência da lactase, principalmente no norte da Europa, o exame genético passou a ser outra ferramenta diagnóstica mais confortável para o intolerante. No Brasil, 43% dos brancos e dos mulatos têm alelo de persistência da lactase, sendo a hipolactasia mais frequente entre os negros e japoneses. Entretanto, na prática clínica indivíduos com hipolactasia podem ser orientados a consumir alguns derivados do leite e alimentos contendo lactose sem apresentar sintomas de intolerância, enquanto que outros terão que fazer restrição de lactose na dieta. ConceitoMá absorção ou má digestão de lactose é a diminuição na capacidade de hidrolisar a lactose, que é resultante da hipolactasia. A hipolactasia significa diminuição da atividade de enzima lactase na mucosa do intestino delgado 1 , também denominada recentemente de "lactase não persistente" 2 . O aparecimento de sintomas abdominais por má absorção de lactose caracteriza a intolerância à lactose. A má absorção de lactose nem sempre provoca sintomas de intolerância à lactose 1 . Após o desmame, ocorre uma redução geneticamente programada e irreversível da atividade da lactase na maioria das populações do mundo, cujo mecanismo é desconhecido, resultando em má absorção primária de lactose 3 . Porém, a hipolactasia também pode ser secundária a doenças que causem dano na borda em escova da mucosa do intestino delgado ou que aumentem significativamente o tempo de trânsito intestinal, como nas enterites infecciosas, giardíase 4 , doença celíaca 5 , doença inflamatória intestinal (especialmente doença de Crohn), enterites induzidas por drogas ou radiação, doença diverticular do cólon 6 e anemia (estudo em ratos, mostrando diminuição na expressão gênica) 7 . Diferentemente da hipolactasia primária do adulto, a hipolactasia secundária é transitória e reversível 8 . Enzima lactase-florizina hidrolase da família 1 das glicosil hidrolasesA estrutura primária traduzida da enzima lactase-florizina hidrolase foi deduzida a partir de sequências de cDNA, apresentando 1927 aminoácidos (NP_002290.2-número de acesso no NCBI), sendo que as duas atividades de lactase e florizina hidrolase (glicosilceramidase) se localizam no mesmo polipeptídeo 9 . A estrutura inicial tem peso molecular de 215000 e, após ser processada provavelmente no complexo de Golgi, o peso molecular cai para 160000, se ancorando na membrana da borda em escova do enterócito 10 , poré...

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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

Cited by 40 publications

References 22 publications

Diagnosis of adult-type hypolactasia/lactase persistence: genotyping of single nucleotide polymorphism (SNP C/T-13910) is not consistent with breath test in Colombian Caribbean population

Whey Lactose as a Raw Material for Microbial Production of Biodegradable Polyesters

Experimental study of lactose hydrolysis and separation in cstr-uf membrane reactor

Understanding lactose intolerance and the dietary management thereof

Intolerância à lactose: mudança de paradigmas com a biologia molecular

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