<unk>  is a condition where the sugar xylitol, a pentose, presents in the urine in unusually high concentrations. It was characterized as an inborn error of carbohydrate metabolism in 1908. It is associated with a deficiency of L-xylulose reductase, necessary for xylitol metabolism. L-Xylulose is a reducing sugar, so it may give false diagnosis of diabetes, as it is found in high concentrations in urine. However glucose metabolism is normal in people with<unk> , and they are not diabetic. Patients of<unk>  have a low concentration of the sugar d-xyloketose. Using phenyl pentosazone crystals, phloroglucin reaction, and absorption spectrum, pentose can be traced back as the reducing substance in urine, with those that have<unk> . Research has shown that<unk>  appears in 3 forms. The most widely studied is essential<unk> , where a couple of grams of L-xylusol are released into a person's system daily. L-xylulose reductase, contained in red blood cells, is composed of both a major and minor isozyme. For those diagnosed with essential<unk> , the major isozyme appears to be the same as the minor one. Alimentary<unk>  can be acquired through fruits high in pentose. Finally, drug-induced<unk>  can be developed by those exposed to morphine, fevers, allergies, and some hormones. Those diagnosed with<unk>  are predominantly of Jewish root. However, it is a harmless defect, and no cure is needed.
Pentosuria
Ketonuria
Sialuria
Uricosuria
Beeturia
Xanthinuria
Lipiduria
Chyluria