Cystinuria in arab countries.

Recent advances in molecular biology have provided new insights into the pathophysiology and genetics of cystinuria. It is expected that future development will be based on molecular and gene therapy. Until then, the therapy in cystinuric patients remains a difficult task and the goal should be the prevention of recurrences. This can be achieved by full compliance with medical regimens that result in significantly reduced urinary cystine excretion and good long-term prognosis in most patients. Such measures include urinary alkalinization with potassium citrate, modest reduction of dietary sodium and maintenance of a daily urinary volume of about three liters to prevent stone recurrence in adult cystinuric patients. The use of life-long pharmacological agents with disulfide chelators should be reserved for patients who fail the general conservative therapy. Invasive surgery should be used only minimally so as to preserve renal anatomy and function. However, repeated episodes of obstructive uropathy, frequently complicated by infection may eventually result in the need for nephrectomy, and are significantly associated with development of chronic renal failure. In the Arab World we lack properly designed epidemiological studies on renal stone-disease in general, and the cystine stones in particular. We recommend a multi-center study to determine the incidence of the disease and a molecular genetic analysis of cystinuric patients and their relatives, to determine the different mutations in our population and the types of the disease both the homozygotes and the heterozygotes.