Clinical Characteristics

The main characteristics of Coffin Siris syndrome (CSS), although not present in all patients with a SMARCA4 change, are:

  • intellectual disability
  • speech delay
  • feeding difficulties
  • absent or small nail(s) of the fifth finger and/or toe
  • excessive hair growth (hypertrichosis)
  • certain facial features (e.g. sparse scalp hair, flat nose, large lips).

Other features could be:

  • agenesis of the corpus callosum
  • frequent infections
  • laryngo- or tracheomalacia.