Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015695 (fatty liver)
 13,941 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Refsum disease is caused by a deficiency of phytanoyl-CoA hydroxylase (PHYH), the first enzyme of the peroxisomal alpha-oxidation system, resulting in the accumulation of the branched-chain fatty acid phytanic acid. The main clinical symptoms are polyneuropathy, cerebellar ataxia, and retinitis pigmentosa. To study the pathogenesis of Refsum disease, we generated and characterized a Phyh knockout mouse. We studied the pathological effects of phytanic acid accumulation in Phyh(-/-) mice fed a diet supplemented with phytol, the precursor of phytanic acid. Phytanic acid accumulation caused a reduction in body weight, hepatic steatosis, and testicular atrophy with loss of spermatogonia. Phenotype assessment using the SHIRPA protocol and subsequent automated gait analysis using the CatWalk system revealed unsteady gait with strongly reduced paw print area for both fore- and hindpaws and reduced base of support for the hindpaws. Histochemical analyses in the CNS showed astrocytosis and up-regulation of calcium-binding proteins. In addition, a loss of Purkinje cells in the cerebellum was observed. No demyelination was present in the CNS. Motor nerve conduction velocity measurements revealed a peripheral neuropathy. Our results show that, in the mouse, high phytanic acid levels cause a peripheral neuropathy and ataxia with loss of Purkinje cells. These findings provide important insights in the pathophysiology of Refsum disease.
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PMID:Ataxia with loss of Purkinje cells in a mouse model for Refsum disease. 1900 1

Mitochondrial neurogastrointestinal encephalopathy (MNGIE) is an autosomal recessive mitochondriopathy caused by loss-of-function mutations in the thymidine phosphorylase gene. The disease leads to premature death and is characterized by gastrointestinal dysmotility and cachexia, external ophthalmoplegia, a sensorimotor neuropathy, and leukoencephalopathy. Bone marrow transplantation (BMT) is the only potentially curative treatment that can achieve a sustained biochemical correction of the metabolic imbalances.We report a 23-year-old male homozygous for the c.866A > C, p.Glu289Ala mutation of the TYMP gene, who presented with fatty liver and cachexia. Laboratory examinations were unremarkable except for increased transaminase activities. Grade II fibrosis and steatosis was found in an initial and a follow-up liver biopsy 4 years later. Myeloablative conditioning and BMT was performed 10 years after initial presentation due to the progressive weight loss and polyneuropathy. Pre-transplant liver staging was normal except for an elevated transient elastography of 31.6 kPa. Severe ascites developed after transplantation and liver function deteriorated progressively to liver failure. Despite engraftment on day +15, the patient died on day +18 from liver failure. Autopsy revealed micronodular liver cirrhosis, and postmortem diagnosis of acute-on-chronic liver failure was done.This case illustrates the difficulties and importance of diagnosing liver cirrhosis in MNGIE. Before BMT, patients must be carefully evaluated by transient elastography, liver biopsy, or assessment of hepatic venous pressure gradient. In patients with liver cirrhosis, further studies should evaluate if liver transplantation may be an alternative to BMT. Considerable amounts of thymidine phosphorylase are expressed in liver tissue which may prevent accumulation of toxic metabolites.
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PMID:MNGIE Syndrome: Liver Cirrhosis Should Be Ruled Out Prior to Bone Marrow Transplantation. 2343 Jul 99