LD20.1

ICD-11 MMS 2026-01

Syndromes with lissencephaly as a major feature

Description

The term lissencephaly covers a group of rare malformations sharing the common feature of anomalies in the appearance of brain convolutions (characterised by simplification or absence of folding) associated with abnormal organisation of the cortical layers as a result of neuronal migration defects during embryogenesis. Children with lissencephaly have feeding and swallowing problems, muscle tone anomalies (early hypotonia and subsequently limb hypertonia), seizures (in particular, infantile spasms) and severe psychomotor retardation. Two large groups can be distinguished: classical lissencephaly (and its variants) and cobblestone lissencephaly.

Index terms

  • Syndromes with lissencephaly as a major feature
  • Agyria
  • Pachygyria
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  • Classic lissencephaly
  • Lissencephaly type 1
  • Lissencephaly type 1 due to doublecortin gene mutation
  • Subcortical band heterotopia
  • Miller-Dieker syndrome
  • 17p13.3 deletion
  • 17p13.3 microdeletion syndrome
  • Lissencephaly due to 17p13.3 deletion
  • Monosomy 17p13.3
  • Telomeric deletion 17p
  • Lissencephaly type 1 due to LIS1 gene mutation
  • Isolated lissencephaly type 1 without known genetic defects
  • Lissencephaly type 2
  • Lissencephaly type 3
  • Neu-Laxova syndrome
  • Lissencephaly type 3 - familial fetal akinesia sequence
  • Lissencephaly type 3 - metacarpal bone dysplasia
  • Lissencephaly with cerebellar hypoplasia
  • Lissencephaly with cerebellar hypoplasia type A
  • Lissencephaly with cerebellar hypoplasia type B
  • Lissencephaly with cerebellar hypoplasia type C
  • Lissencephaly with cerebellar hypoplasia type D
  • Lissencephaly with cerebellar hypoplasia type E
  • Lissencephaly with cerebellar hypoplasia type F
  • Microlissencephaly
  • Microlissencephaly type A
  • Lissencephaly syndrome, Norman-Roberts type
  • Microlissencephaly type B
  • Lissencephaly due to TUBA1A gene mutation
  • X-linked lissencephaly - agenesis of corpus callosum - genital anomalies
  • Craniotelencephalic dysplasia
  • Micro syndrome
  • WARBM1 - [Warburg Micro syndrome]
  • Warburg Micro syndrome
  • Iris coloboma with ptosis - intellectual deficit

Inclusions

  • Agyria
  • Pachygyria

Exclusions from above levels

  • LD2F.13 – Meckel syndrome
  • http://id.who.int/icd/entity/733825440 – Inborn errors of metabolism

Sibling codes

  • LD20.0 – Syndromes with cerebellar anomalies as a major feature
  • LD20.2 – Syndromes with microcephaly as a major feature
  • LD20.3 – Syndromes with holoprosencephaly as a major feature
  • LD20.4 – Syndromes with brain calcifications as a major feature
  • LD20.Y – Other specified syndromes with central nervous system anomalies as a major feature
  • LD20.Z – Syndromes with central nervous system anomalies as a major feature, unspecified

Foundation entity

Syndromes with lissencephaly as a major feature – http://id.who.int/icd/entity/805385297

Part of: LD20: Syndromes with central nervous system anomalies as a major feature › 20: Developmental anomalies