NOVATO, Calif., Oct. 23, 2013 (GLOBE NEWSWIRE) -- Raptor Pharmaceutical Corp. (Nasdaq:RPTP) and DaVita Clinical Research ® (DCR ®) (NYSE:DVA) today announced a collaboration to screen blood samples from patients with end-stage renal disease (ESRD) in an effort to identify patients with unrecognized late-onset nephropathic cystinosis. DCR will supply blood samples with clinical data annotation from DCR's biorepository of over four thousand patients with ESRD. The screening effort will employ high-throughput genetic sequencing of the cystinosin, lysosomal cystine transporter (CTNS) gene, mutations of which result in cystinosis. Results of the collaboration may reveal new insights into the prevalence of missed late-onset cystinosis in this at-risk patient population. "Today, most nephropathic cystinosis patients are identified in infancy by pediatric nephrologists, yet, as with many genetic diseases, later-onset patients have been identified where the clinical manifestations of cystinosis may go unrecognized well into adulthood," noted Christopher M. Starr, Ph.D., Raptor's chief executive officer. "We believe these late-onset patients are likely to present with ESRD as adults and this screening program, initiated with this collaboration, may help adult nephrologists, many of whom are unfamiliar with the late onset form of the disease, identify patients who suffer from cystinosis." The CTNS gene is responsible for coding for the protein cystinosin, which is responsible for transporting the amino acid cystine out of the lysosome in cells. The accumulation of cystine is toxic to every cell, and can therefore affect all tissues and organs in the body, most notably the kidneys. "Nephropathic cystinosis is such a rare disease that it is likely that some cases have not been characterized in the adult population," said Amy Young, vice president and general manager of DaVita Clinical Research. "Our biorepository was designed and collected to enable this type of discovery and we are pleased to embark on a project that has the potential to improve clinical outcomes for ESRD patients."