Objective(s) Primary or adult type hypolactasia, the most common enzyme deficiency in the world, is due to reduced lactase activity in the intestinal cell after weaning. Lactase non-persistence is inherited as an autosomal recessive trait. A DNA variant, single nucleotide polymorphism C/T−13910 which is located on 13910 base pairs (bp) upstream of the lactase gene (LCT) at chromosome 2 has been...

BACKGROUND Adult-type hypolactasia is caused by genetic lactase non-persistence. It is the most common cause of lactose intolerance, which results in gastrointestinal symptoms after ingestion of dairy products. Currently, lactose intolerance is investigated by the hydrogen breath test (HBT), which is considered the preferred diagnostic test. Adult-type hypolactasia may also be diagnosed by geno...

Hypolactasia, or intestinal lactase deficiency, affects more than half of the world population. Currently, xylose quantification in urine after gaxilose oral administration for the noninvasive diagnosis of hypolactasia is performed with the hand-operated nonautomatable phloroglucinol reaction. This work demonstrates that a new enzymatic xylose quantification method, based on the activity of xyl...

BACKGROUND & OBJECTIVES Prevalence of adult-type hypolactasia is known to vary among different countries and in different ethnic populations in the same country. The present study was undertaken to evaluate the prevalence of hypolactasia and lactose intolerance in three different ethnic populations living in similar environmental conditions in Malaysia. The correlation between different symptom...

Objectives The frequency of adult-type hypolactasia (lactase non-persistence) varies widely among different ethnic groups. The cultural historical hypothesis assumes a link between the occurrence of hypolactasia and the distribution of dairy farming. The nomadic Nenets have been reindeer herders for generations and have therefore not consumed any dairy products. The hypotheses here was that the...

Lactase-phlorizin hydrolase (LPH), a membrane-bound glycoprotein present in the luminal surface of enterocytes in the intestine is responsible for lactose intolerance, a phenomenon prevalent in humans worldwide. In the rodent intestine, the post-natal development of the LPH follows a specific pattern, such that the enzyme levels are high in the peri-natal period, but declines considerably upon ...

This thesis is based on the following original articles, which are referred to in the text by their Roman numerals. In addition, some unpublished data are presented Assignment of the locus for congenital lactase deficiency to 2q21, in the vicinity of but separate from the lactase-phlorizin hydrolase gene. Identification of a variant associated with adult-type hypolactasia. Transcriptional regul...

I write in response to the article by Rasinperä and colleagues (Gut 2004;53:1571–6) in which a DNA test was proposed for ‘‘adulttype hypolactasia’’. The ability to digest the milk sugar lactose as an adult (lactase persistence) is a variable genetic trait in human populations, lactase persistence being the most frequent phenotype in Northern Europe, while lactase nonpersistence or ‘‘adult-type ...