Cronkhete-Canada syndrome is described by American doctors L M. Cronkhite and WJ Canada in 1955. This syndrome is a complex of congenital anomalies: generalized polyposis of the gastrointestinal tract (including duodenum and stomach), atrophy of nails, alopecia, skin hyperpigmentation, sometimes in combination with exudative enteropathy, a syndrome of insufficiency of absorption, hypocalcemia, potassium and magnesium.