KB63.4

ICD-11 MMS 2026-01

Transitory tyrosinaemia of newborn

Description

Clinically asymptomatic elevated blood tyrosine level caused by late fetal maturation of 4-hydroxyphenylpyruvate dioxygenase, usually detected on newborn bloodspot screening. Most commonly seen in premature infants receiving milk formulae with high protein content. Generally considered benign and resolves by 4-6 weeks of age.

Coding note from above levels

Conditions arising in the perinatal period, even though death or morbidity occurs later, should, as far as possible, be coded to chapter 19, which takes precedence over chapters containing codes for diseases by their anatomical site. For children less than 28 days old, assume that a reported condition developed in the perinatal period, unless the duration is stated and the onset was after the first completed week of life.

Index terms

  • Transitory tyrosinaemia of newborn
  • neonatal tyrosinemia
  • transient neonatal hypertyrosinemia
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  • transitory neonatal tyrosinemia

Exclusions from above levels

  • 01 – Certain infectious or parasitic diseases - acquired after birth
  • 02 – Neoplasms
  • 05 – Endocrine, nutritional or metabolic diseases
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  • 08 – Certain congenital diseases of the nervous system
  • 20 – Congenital malformations, deformations and chromosomal abnormalities
  • 22 – Injury, poisoning or certain other consequences of external causes
  • 3A10 – Hereditary haemolytic anaemia
  • 4A01.03 – Transient hypogammaglobulinaemia of infancy
  • 9B71.3 – Retinopathy of prematurity
  • BC43 – congenital cardiomyopathy
  • DA93.0 – Paralytic ileus
  • EA50.Z – Pemphigus neonatorum
  • EH40.00 – Cradle cap
  • http://id.who.int/icd/entity/588616678 – Gastroenteritis or colitis of infectious origin
  • http://id.who.int/icd/entity/609214049 – Congenital gonococcal infection

Sibling codes

  • KB63.0 – Late metabolic acidosis of newborn
  • KB63.1 – Dehydration of newborn
  • KB63.2 – Disturbances of sodium balance of newborn
  • KB63.3 – Disturbances of potassium balance of newborn
  • KB63.5 – Metabolic bone disease of prematurity

Foundation entity

Transitory tyrosinaemia of newborn – http://id.who.int/icd/entity/25668130

Part of: KB63: Certain specified transitory neonatal electrolyte or metabolic disturbances › 19: Certain conditions originating in the perinatal period