Niemann–Pick disease is a group of severe inherited metabolic disorders, in which sphingomyelin accumulates in lysosomes in cells (the lysosomes normally degrade material that comes from out of cells). These disorders involve the dysfunctional metabolism of sphingolipids, which are fats found in cell membranes. They can be considered as a kind of sphingolipidosis, which is included in the larger family of lysosomal storage diseases. Signs and symptoms
Symptoms are related to the organs in which sphingomyelin accumulates. Enlargement of the liver and spleen (hepatosplenomegaly) may cause reduced appetite, abdominal distension, and pain. Enlargement of the spleen (splenomegaly) may also cause low levels of platelets in the blood (thrombocytopenia).Accumulation of sphingomyelin in the central nervous system (including the cerebellum) results in unsteady gait (ataxia), slurring of speech (dysarthria), and difficulty swallowing (dysphagia). Basal ganglia dysfunction causes abnormal posturing of the limbs, trunk, and face (dystonia). Upper brainstem disease results in impaired voluntary rapid eye movements (supranuclear gaze palsy). More widespread disease involving the cerebral cortex and subcortical structures causes gradual loss of intellectual abilities, causing dementia and seizures.Bones also may be affected, with the disease causing enlarged bone marrow cavities, thinned cortical bone, or a distortion of the hip bone called coxa vara. Sleep-related disorders also occur with the condition, such as sleep inversion, sleepiness during the day and wakefulness at night. Gelastic cataplexy, the sudden loss of muscle tone when the affected patient laughs, is also seen. Causes
Mutations in the SMPD1 gene cause Niemann–Pick disease types A and B.
Maralixibat chloride, sold under the brand name Livmarli, is a medication used to treat cholestatic pruritus in people with Alagille syndrome. Maralixibat chloride is an ileal bile acid transporter (IBAT) inhibitor.Maralixibat was approved for medical use in the United States in September 2021. History
Maralixibat was granted orphan drug designations in 2013, and in 2020. Society and culture
Legal status
On 13 October 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization under exceptional circumstances for the medicinal product Livmarli, intended for the treatment of cholestatic pruritus in patients with Alagille syndrome (ALGS). The applicant for this medicinal product is Mirum Pharmaceuticals International B.V.

Names
Maralixibat chloride is the international nonproprietary name (INN). References
External links
"Maralixibat". Drug Information Portal. U.S. National Library of Medicine. "Maralixibat chloride". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT02160782 for "Safety and Efficacy Study of LUM001 (Maralixibat) With a Drug Withdrawal Period in Participants With Alagille Syndrome (ALGS) (ICONIC)" at ClinicalTrials.gov