Modern diagnostic approach to hereditary xanthinuria
| Authors | |
|---|---|
| Year of publication | 2015 |
| Type | Article in Periodical |
| Magazine / Source | Urolithiasis |
| MU Faculty or unit | |
| Citation | |
| Doi | http://dx.doi.org/10.1007/s00240-014-0734-4 |
| Field | Other specializations of internal medicine |
| Keywords | Hereditary xanthinuria; Allopurinol loading test; Intestinal biopsy; Liver biopsy; Urinary metabolomics; Molecular genetics |
| Description | Hereditary xanthinuria (HX) is a rare inherited disorder caused by a deficiency of xanthine dehydrogenase/oxidase (XDH/XO). Missing XDH/XO activity leads to undetectable levels of uric acid excessively replaced by xanthine in serum/urine. The allopurinol loading test has been traditionally used to differentiate between HX types I and II. Final confirmation of HX has been based on the biopsy finding of the absent XDH/XO activity in the small intestine or liver. We present the clinical, biochemical, ultrasound and molecular genetics findings in three new patients with HX and suggest a simple three-step approach to be used for diagnosis, typing and confirmation of HX. In the first step, the diagnosis of HX is determined by extremely low serum/urinary uric acid excessively replaced by xanthine. Second, HX is typed using urinary metabolomics. Finally, the results are confirmed by molecular genetics. We advocate for this safe and non-invasive diagnostic algorithm instead of the traditional allopurinol loading test and intestinal or liver biopsy used in the past. |