Prevalence of Primary Adult Lactose Malabsorption in the Eastern Province of Saudi Arabia

Dissanayake, A.S.; El-Munshid, Hassan A.; Al-Quorain, Abdulaziz; Al-Breiki, Hassan; Al‐Idrissi, Hassan Y.; Wosornu, Ladé

doi:10.5144/0256-4947.1990.598

Cited by 8 publications

(5 citation statements)

References 14 publications

(13 reference statements)

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“…In Africa, the distribution is patchy, with some pastoralist nomadic tribes having high frequencies of lactase persistence compared with neighbouring groups living in the same country (Bayoumi et al 1981(Bayoumi et al , 1982, with a similar pattern observed between Bedouin and neighbouring populations in the Middle East (Fig. 2, Cook and al-Torki 1975;Dissanyake et al 1990;Snook et al 1976). …”

Section: Worldwide Distribution Of Lactase Persistencementioning

confidence: 79%

Lactose digestion and the evolutionary genetics of lactase persistence

et al. 2008

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It has been known for some 40 years that lactase production persists into adult life in some people but not in others. However, the mechanism and evolutionary significance of this variation have proved more elusive, and continue to excite the interest of investigators from different disciplines. This genetically determined trait differs in frequency worldwide and is due to cis-acting polymorphism of regulation of lactase gene expression. A single nucleotide polymorphism located 13.9 kb upstream from the lactase gene (C-13910 > T) was proposed to be the cause, and the -13910*T allele, which is widespread in Europe was found to be located on a very extended haplotype of 500 kb or more. The long region of haplotype conservation reflects a recent origin, and this, together with high frequencies, is evidence of positive selection, but also means that -13910*T might be an associated marker, rather than being causal of lactase persistence itself. Doubt about function was increased when it was shown that the original SNP did not account for lactase persistence in most African populations. However, the recent discovery that there are several other SNPs associated with lactase persistence in close proximity (within 100 bp), and that they all reside in a piece of sequence that has enhancer function in vitro, does suggest that they may each be functional, and their occurrence on different haplotype backgrounds shows that several independent mutations led to lactase persistence. Here we provide access to a database of worldwide distributions of lactase persistence and of the C-13910*T allele, as well as reviewing lactase molecular and population genetics and the role of selection in determining present day distributions of the lactase persistence phenotype.

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Section: Worldwide Distribution Of Lactase Persistencementioning

confidence: 79%

Lactose digestion and the evolutionary genetics of lactase persistence

et al. 2008

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“…The frequency of lactase persistence has been shown to be moderately well correlated with the cultural habit of drinking fresh milk (Holden and Mace 1997). For example, African pastoralists have been reported to show a higher incidence of lactase persistence than non-pastoralists (Bayoumi et al 1981(Bayoumi et al , 1982, and lactase persistence is more frequent in Bedouins (who are known to consume appreciable amounts of fresh milk) than in neighbouring non-Bedouin Arabs (Cook and al-Torki 1975;Snook et al 1976;Hijazi et al 1983;Dissanyake et al 1990). …”

Section: Introductionmentioning

confidence: 93%

“…We included three diVerent Bedouin groups because of the known high incidence of lactase persistence in the Bedouin (Cook and al-Torki 1975;Snook et al 1976;Hijazi et al 1983;Dissanyake et al 1990). Critically, we report for the Wrst time the results of an association study in a cohort of Sudanese volunteers.…”

Section: Introductionmentioning

confidence: 99%

A novel polymorphism associated with lactose tolerance in Africa: multiple causes for lactase persistence?

et al. 2006

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Persistence or non-persistence of lactase expression into adult life is a polymorphic trait that has been attributed to a single nucleotide polymorphism (C-13910T) in an enhancer element 13.9 kb upstream of the lactase gene (LCT). The -13910*T allele occurs at very high frequency in northern Europeans as part of a very long haplotype (known as A), and promotes binding of the transcription factor Oct-1. However, -13910*T is at very low frequency in many African milk drinking pastoralist groups where lactase persistence phenotype has been reported at high frequency. We report here for the first time, a cohort study of lactose digester and non-digester Sudanese volunteers and show there is no association of -13910*T or the A haplotype with lactase persistence. We support this finding with new genotype/phenotype frequency comparisons in pastoralist groups of eastern African and Middle Eastern origin. Resequencing revealed three new SNPs in close proximity to -13910*T, two of which are within the Oct-1 binding site. The most frequent of these (-13915*G) is associated with lactose tolerance in the cohort study, providing evidence for a cis-acting effect. Despite its location, -13915*G abolishes, rather than enhances Oct-1 binding, indicating that this particular interaction is unlikely to be involved in lactase persistence. This study reveals the complexity of this phenotypic polymorphism and highlights the limitations of C-13910T as a diagnostic test for lactase persistence status, at least for people with non-European ancestry.

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“…In India, the frequency of lactase persistence is higher in the north than the south, and in the rest of the world, lactase persistence frequency is generally low. In Africa, the distribution is patchy, with some pastoralist nomadic tribes having high frequencies of lactase persistence compared with the neighbouring groups inhabiting the same country [33], with a similar pattern observed between Bedouin and neighbouring populations in the Middle East [34,35].…”

Section: Lactose Intolerance and Its Prevalence In Other Countriesmentioning

confidence: 97%

Occurrence of Lactose Intolerance among Ethiopians

M¹,

K²

2015

J Food Process Technol

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Milk has been known as nature's most complete Food. Among the components of milk is lactose. Some people who lack the enzyme needed to digest lactose suffer from lactose intolerance and therefore cannot digest milk. Worldwide, nearly 70 percent of the adult population is thought to be lactose intolerant, and the condition is very common among American Indians and those of Asian, African, Hispanic, and Mediterranean descent. Lactose intolerance is one of the factors affecting milk demand and consumption, which subsequently influencing milk market/ productivity. But no information is available on lactose intolerance in Ethiopia. Therefore, this paper is the first attempt to study the incidence of lactose intolerance in the country. The aim of the paper, therefore, was to generate information on lactose intolerance through case study approach including questionnaire survey and document analysis. In the case study area of Ada district of Eastern Shoa of Ethiopia, out of 188 households/individuals surveyed, 7.45% of the respondents reported that they don't consume milk but consume fermented milk ('Ergo'). The majority reported symptoms of lactose intolerance (71.4% get vomiting upon consuming milk, 28.6% feel abdominal pain). The percentage of occurrence of lactose intolerance found in the survey is believed to affect the milk consumption in the country. Dairy processors need to make yoghurt or remove lactose, for consumers with special dietary requirements/lactose intolerance/to improve milk consumption. Awareness about lactose intolerance also needs to be created in the society by health extension workers.

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Prevalence of Primary Adult Lactose Malabsorption in the Eastern Province of Saudi Arabia

Cited by 8 publications

References 14 publications

Lactose digestion and the evolutionary genetics of lactase persistence

Lactose digestion and the evolutionary genetics of lactase persistence

A novel polymorphism associated with lactose tolerance in Africa: multiple causes for lactase persistence?

Occurrence of Lactose Intolerance among Ethiopians

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