Chedíak-Higashi Syndrome: Hair-to-toe spectrum

Abstract

Chedíak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder caused by mutations in the Lysosomal Trafficking Regulator (LYST) gene, leading to defective lysosomal function in immune cells, melanocytes, and neurons. Clinically, CHS is characterized by a spectrum of symptoms, including immunodeficiency, partial oculocutaneous albinism, bleeding tendencies, neurodevelopmental deficits and progressive neurodegenerative symptoms.

The severity of CHS correlates with the type of LYST mutation: the classic form, linked to nonsense or frameshift mutations, presents early in childhood with severe immune dysfunction, recurrent infections, and a high risk of hemophagocytic lymphohistiocytosis (HLH), a life-threatening hyperinflammatory state. Without timely treatment, including hematopoietic stem cell transplantation (HSCT), prognosis is poor, with high mortality in early life. Atypical forms, associated with missense mutations, manifest later with milder immunologic symptoms but inevitably progress to neurological impairment, including cognitive decline and motor dysfunction. Diagnosing CHS is complex due to its rarity, phenotypic variability, and overlap with other disorders. A thorough approach, incorporating clinical evaluation, peripheral blood smear for giant granules in leukocytes, and genetic testing for LYST mutations, is crucial for accurate diagnosis.

Management of CHS requires a multidisciplinary approach, focusing on HSCT for immunologic and hematologic stabilization and symptomatic and supportive care for neurological symptoms. Even those patients who undergo stabilizing HSCT eventually develop neurological difficulties. This review provides an in-depth exploration of CHS, covering its epidemiology, clinical presentation, molecular genetics, diagnostic challenges, and current management strategies, while emphasizing the necessity of a comprehensive, multidisciplinary approach to improve patient outcomes.