“Xanthinuria”, Victor McKusick, Mendelian Inheritance in Man, 1966. 黄原尿症。(XAN).

Here I present: “Xanthinuria”, Victor McKusick, Mendelian Inheritance in Man’, 1966. 黄原尿症。(XAN).

INTRODUCTION.

Xanthinuria is a genetic disorder causing the accumulation of xanthine. It is caused by a deficiency of the enzyme xanthine dehydrogenase.

Xanthinuria, which was first described in 1954 by Dent and Philpot is characterized by excretion of large amounts of xanthine in the urine and a tendency to form xanthine stones. Uric acid is strikingly diminished in serum and urine. Two (2) clinically similar but distinct forms of xanthinuria are recognized. In type-I (XAN1) there is an isolated deficiency of xanthine dehydrogenase, and in type-II (XAN2) there is a dual deficiency of xanthine dehydrogenase and aldehyde oxidase.

There is evidence that Xanthinuria type-1 is caused by a mutation in the xanthine dehydrogenase (Enzyme Commission number EC# 1.17.3.2) gene (XDH) on cytogenetic location 2p23.1 and genomic coordinates 2:31,334,321-31,414,742.  The screenshot of the XDH gene 80,422 bp (base pairs) of DNA sequence length is shown BELOW.  Nine (9) other genes besides XDH are listed BENEATH.