Acquired lactase deficiency

The question has arisen of whether lactase deficiency is inherited or acquired. In most mammals, lactase declines to low levels or is entirely absent after weaning. It would seem entirely feasible that it could be an acquired characteristic in people who customarily do not drink milk. 

Lactose is sometimes detected in the urine of women during lactation and occasionally toward the end of pregnancy. Patients with lactase deficiency, a common disorder caused by a congenital or acquired deficiency of intestinal lactase, exhibit abdominal pain, diarrhea, and lactose in the urine. 

A specific lactase deficiency which may be congenital or acquired. 

An intestinal disaccharidase which cleaves lactose to yield glucose and galactose. Lactase deficiency can occur which may be congenital or acquired. 

Inborn or acquired (postinfection) enzyme deficiencies, e.g., deficiency of lactase, may lead to milk intolerance. 

EXAMPLE 11.5 What is the consequence of an acquired or inherited deficiency of lactase ... 

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