Pallister-Hall syndrome

Pallister-Hall syndrome (PHS) is a rare genetic disorder caused by mutations in the GLI3 gene, which plays a critical role in embryonic development and the hedgehog signaling pathway. The condition is characterized by a combination of hypothalamic hamartoma (a benign tumor-like malformation in the brain), polydactyly (extra fingers or toes, often central or postaxial), and other developmental anomalies. The syndrome affects multiple body systems, including the central nervous system, skeletal system, endocrine system, and internal organs. Key clinical features include hypothalamic hamartoma, which can cause pituitary dysfunction leading to hormonal deficiencies (such as growth hormone deficiency, adrenal insufficiency, or panhypopituitarism), bifid epiglottis or other airway anomalies, imperforate anus, and renal abnormalities. Polydactyly in PHS often presents as mesoaxial (insertional) polydactyly or postaxial polydactyly, and syndactyly (fused digits) may also be present. The severity of the condition is highly variable, even within the same family — some individuals may have life-threatening complications in the neonatal period, while others have mild features that may go undiagnosed for years. There is no cure for Pallister-Hall syndrome, and treatment is supportive and symptom-directed. Management may include hormone replacement therapy for pituitary insufficiency, surgical correction of polydactyly or imperforate anus, and monitoring of the hypothalamic hamartoma. Airway anomalies such as bifid epiglottis require careful evaluation, particularly before any surgical procedures requiring intubation. Genetic counseling is recommended for affected families, as the condition follows an autosomal dominant inheritance pattern with variable expressivity. Early diagnosis and coordinated multidisciplinary care can significantly improve outcomes.

Common questions about Pallister-Hall syndrome