ICD-11 classes
20 Developmental anomalies
LD90 — Conditions with disorders of intellectual development as a...
LD20.1 — Syndromes with lissencephaly as a major feature

ICD-11 LD20.1 — Syndromes with lissencephaly as a major feature

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.

The diagnosis excludes nothing.

It has no clarifying diagnoses.

The diagnosis is coded elsewhere:

• Syndromes with central nervous system anomalies as a major feature #8737
• Syndromes with central nervous system anomalies as a major feature #23200