5C61.61

ICD-11 MMS 2026-01

Congenital lactase deficiency

Description

This is a congenital deficiency of lactase (EC 3.2.1.108), inherited as an autosomal recessive trait, presenting in infancy and manifested by profuse watery diarrhoea in response to dietary milk, due to inability to digest lactose, a sugar found in milk and to a lesser extent milk-derived dairy products. The condition may lead to marasmus and death if lactose is not eliminated from the diet.

Index terms

  • Congenital lactase deficiency
  • CLD - [congenital lactase deficiency]
  • congenital alactasia
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  • congenital alactasia syndrome
  • congenital lactose intolerance
  • congenital lactose malabsorption
  • disaccharide intolerance 2
  • disaccharide intolerance type 2
  • hereditary alactasia
  • hereditary lactase deficiency
  • lactose intolerance of newborn

Exclusions from above levels

  • 3A10.Z – Hereditary haemolytic anaemia due to enzyme deficiency
  • 5A71.01 – Congenital adrenal hyperplasia
  • 5A81.1 – 5-alpha-reductase deficiency
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  • LD28.01 – Marfan syndrome
  • LD28.1 – Ehlers-Danlos syndrome
  • LD2A.4 – androgen resistance syndrome
  • 18 – Pregnancy, childbirth or the puerperium
  • http://id.who.int/icd/entity/1004987305 – Transitory endocrine or metabolic disorders specific to fetus or newborn

Sibling codes

  • 5C61.60 – Primary lactase deficiency
  • 5C61.62 – Secondary lactase deficiency
  • 5C61.6Z – Lactose intolerance, unspecified

Foundation entity

Congenital lactase deficiency – http://id.who.int/icd/entity/2109252471

Part of: 5C61.6: Lactose intolerance › 5C61: Disorders of carbohydrate absorption or transport › 05: Endocrine, nutritional or metabolic diseases