[The underlying cause of kidney disease is often unknown in dialysis patients: a possible genomic approach].

As much as 16-17% European and American patients on renal replacement therapy do not have a conclusive diagnosis of the cause of their renal failure. This may have important implications on the types of morbidity they can develop in case of systemic diseases with extrarenal involvement, or recurrent renal diseases in transplanted patients. A better knowledge of the underlying disease can have important prognostic and therapeutic repercussions. In this study we evaluated the rate of uremic patients who can benefit from a genomic diagnostic approach. Patients liable to a future genomic diagnostic study were selected based on two criteria: (i) age of dialysis entry less or equal to 55 years, and (ii) presence of a non-conclusive diagnosis. Based on the data extracted from the REGDIAL registry, we analyzed 534 patients undergoing renal replacement therapy. We identified 300 patients with age of entry into replacement therapy <55 years (56.2% of the overall study population). Among these, we identified 107 patients with missing or inconclusive diagnosis, which was equal to 20% of the overall population. Of these patients, 32.8% reported a positive family history of kidney disease. This study confirms that a significant proportion of patients on renal replacement therapy do not have an etiological diagnosis and may be subject to a genomic evaluation. With the increasing availability of genomic sequencing technology and the falling of related costs, nephrologists will be increasingly inclined to incorporate clinical genetic testing into their diagnostic armamentarium. There is therefore a need for in-depth, multicenter studies aimed at developing evidence-based guidelines, clear indications and at confirming the usefulness of genetic testing in nephrology.