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Published on: February 9, 2021
A case of hereditary xanthinuria type 1 accompanied by bilateral renal calculi
Yutaka Fujiwara1, Yoshikazu Kawakami, Yoshihiko Shinohara
1Department of Endocrinology and Metabolism, KKR Sapporo Medical Center, Japan. Yutaka-Fujiwara@kkr-smc.com
Abstract:
Hereditary xanthinuria is an extremely rare purine metabolism disorder caused by a genetic abnormality in xanthine dehydrogenase. A new case of hereditary xanthinuria type 1 accompanied by bilateral renal calculi was encountered. We performed an allopurinol loading test and diagnosed classical type 1 xanthinuria. Through genetic diagnosis, we identified a mutation site in the xanthine dehydrogenase gene. Genetic analysis revealed a homozygous deletion of cytosine 2,567 in the xanthine dehydrogenase gene, and as a result, a stop codon was formed at position 928. Renal failure caused by the deposition of xanthine crystals is a known complication because xanthine is poorly soluble in water. With high fluid intake and low purine diet, no significant increase in calculi has been observed in this patient for 2 years.
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