1. Ribose-5-phosphate isomerase deficiency: new inborn error in the pentose phosphate pathway associated with a slowly progressive leukoencephalopathy.
- Author
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Huck JH, Verhoeven NM, Struys EA, Salomons GS, Jakobs C, and van der Knaap MS
- Subjects
- Base Sequence, Carbohydrates blood, Carbohydrates cerebrospinal fluid, Carbohydrates urine, Fibroblasts, Humans, Metabolism, Inborn Errors enzymology, Metabolism, Inborn Errors genetics, Molecular Sequence Data, Sugar Alcohols blood, Sugar Alcohols cerebrospinal fluid, Sugar Alcohols urine, Aldose-Ketose Isomerases deficiency, Aldose-Ketose Isomerases genetics, Nervous System Diseases enzymology, Nervous System Diseases genetics, Pentose Phosphate Pathway genetics
- Abstract
The present article describes the first patient with a deficiency of ribose-5-phosphate isomerase (RPI) (Enzyme Commission number 5.3.1.6) who presented with leukoencephalopathy and peripheral neuropathy. Proton magnetic resonance spectroscopy of the brain revealed highly elevated levels of the polyols ribitol and D-arabitol, which were subsequently also found in high concentrations in body fluids. Deficient activity of RPI, one of the pentose-phosphate-pathway (PPP) enzymes, was demonstrated in fibroblasts. RPI gene-sequence analysis revealed a frameshift and a missense mutation. Recently, we described a patient with liver cirrhosis and abnormal polyol levels in body fluids, related to a deficiency of transaldolase, another enzyme in the PPP. RPI is the second known inborn error in the reversible phase of the PPP, confirming that defects in pentose and polyol metabolism constitute a new area of inborn metabolic disorders.
- Published
- 2004
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