The incidence of primary hypolactasia amongst native Irish.
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005767:Gastrointestinal Diseases / Q000201:enzymology / Q000209:etiology; D006801:Humans; D007494:Ireland; D007787:Lactose Intolerance / Q000453:epidemiology*; D007789:Lactose Tolerance Test; D008297:Male; D008875:Middle Aged