HHH syndrome

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hyperornithinaemia-hyperammonaemia-homocitrullinuria syndrome

An autosomal recessive disorder (OMIM:238970) caused by hyperammonaemia characterised by a functional impairment of the urea cycle resulting in neurologic symptoms, including mental retardation, spastic paraparesis with pyramidal signs, cerebellar ataxia, and episodic loss of consciousness or coma.

Molecular pathology
Caused by defects in SLC25A15, which encodes a mitochondrial carrier protein that transports ornithine and is a key component of the urea cycle.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

HHH syndrome

An AR condition of early childhood to late adulthood onset characterized by hyperornithinemia, postprandial hyperammonemia and homocitrullinemia, caused by a defect in ornithine transport from the cytoplasm into the mitochondria–where the urea cycle occurs Clinical Chronic vomiting, repeated neurologic attacks after high-protein meals, resulting in seizures, FTT, lethargy, ataxia, choreoathetosis, acute episodic hyperammonemia, or coma, growth and mental retardation Treatment Protein restriction, dietary supplements with ornithine or arginine
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.