Orphanet: Non syndromic bilambdoid and sagittal craniosynostosis

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Non-syndromic bilambdoid and sagittal craniosynostosis

Disease definition

A rare cranial malformation syndrome characterized by the premature closure of both lambdoid sutures and the posterior sagittal suture, resulting in abnormal skull contour (frontal bossing, anterior turricephaly with mild brachycephaly, biparietal narrowing, occipital concavity) and dysmorphic facial features (low-set ears, midfacial hypoplasia). Short stature, developmental delay, epilepsy, and oculomotor dyspraxia have also been reported. Associated anomalies include enlargement of the cerebral ventricles, agenesis of the corpus callosum, Arnold-Chiari malformation type I, venous anomalies of skull, and hydrocephalus.


Classification level: Disorder
  • Synonym(s):
    • BLSS
    • Bilateral lambdoid and sagittal synostosis
    • Isolated sagittal and bilambdoid craniosynostosis
    • Non-syndromic sagittal and bilateral lambdoid synostosis
  • Prevalence: <1 / 1 000 000
  • Inheritance: Autosomal recessive 
  • Age of onset: Neonatal
  • ICD-10: Q87.0
  • OMIM: 218350
  • UMLS: C1857511
  • MeSH: C536455
  • GARD: 1575
  • MedDRA: -
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