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Severe neonatal-onset encephalopathy with microcephaly

Disease definition

Severe neonatal-onset encephalopathy with microcephaly is a rare monogenic disease with epilepsy characterized by neonatal-onset encephalopathy, microcephaly, severe developmental delay or absent development, breathing abnormalities (including central hypoventilation and/or respiratory insufficiency), intractable seizures, abnormal muscle tone and involuntary movements. Early death is usual.


Classification level: Disorder
  • Synonym(s):
    • Severe congenital encephalopathy due to MECP2 mutation
  • Prevalence: <1 / 1 000 000
  • Inheritance: X-linked recessive 
  • Age of onset: Infancy, Neonatal
  • ICD-10: Q02
  • ICD-11: LD20.2
  • OMIM: 300673
  • UMLS: C4749821
  • MeSH: -
  • GARD: -
  • MedDRA: -

Detailed information

General public

  • Article for general public
  • Español (2022) - Asociación Nacional de Personas con Epilepsia-ANPE

Disease review articles

ERN produced/endorsed by ERN(s)   FSMR produced/endorsed by FSMR(s)
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.