Sea Blue Histiocyte Syndrome (SBHS) is a rare genetic disorder characterized by the accumulation of lipid-laden (fat-filled) histiocytes in various organs. The spelling of this medical term can be explained using the International Phonetic Alphabet (IPA) phonetic transcription. "Sea" is pronounced /si/ and "Blue" is /blu/. "Histiocyte" is pronounced /hɪstoʊsaɪt/ and "Syndrome" is pronounced /sɪnˌdroʊm/. Therefore, the correct pronunciation of SBHS is /si blu hɪstoʊsaɪt sɪnˌdroʊm/. Diagnosis is confirmed by testing for the presence of the characteristic "sea-blue" appearance of histiocytes under a microscope.
Sea Blue Histiocyte Syndrome is a rare inherited disorder characterized by the accumulation of sea blue histiocytes in various organs, particularly in the spleen and bone marrow. This syndrome is considered a lysosomal storage disorder, as it results from the abnormal accumulation of lipids, specifically cholesterol and glycolipids, within these sea blue histiocytes.
Typically, individuals affected by Sea Blue Histiocyte Syndrome exhibit a range of symptoms, including an enlarged liver and/or spleen, low blood counts (cytopenias), and neurological abnormalities. These neurological abnormalities can vary and may include intellectual disability, difficulty coordinating movements (ataxia), and seizures. Additionally, individuals may display skin abnormalities, such as yellowish discoloration of the skin (jaundice) and small lipid-filled bumps (xanthomas).
Sea Blue Histiocyte Syndrome is caused by mutations in the gene known as NPC1 (Niemann-Pick type C1), which plays a vital role in the transport and processing of cholesterol and other lipids within cells. The accumulation of cholesterol and glycolipids within the sea blue histiocytes disrupts normal cellular function and leads to the symptoms associated with this syndrome.
Diagnosis of Sea Blue Histiocyte Syndrome is typically made through a combination of clinical evaluation, imaging studies, and laboratory tests. Treatment options for this syndrome are primarily supportive and aim to manage the symptoms present in affected individuals. Genetic counseling may be recommended for individuals who are found to have the genetic mutation causing Sea Blue Histiocyte Syndrome.