Looking in a new place to diagnose eye disease
Duke University study suggests potential for urine test for retinitis pigmentosa diagnosis.
In a collaboration between Bascom Palmer Eye Institute (FL, USA) and Duke University Medical School (NC, USA), researchers have recently published work on a diagnostic test for retinitis pigmentosa (RP) – allowing the identification of patients with a certain mutation affecting the dehydrodolichol diphosphate synthase (DHDDS) gene. This will permit more personalized care to RP patients who have this gene mutation – one of 60 linked to RP.
The DHDDS enzyme is responsible for the synthesis of dolichols; with dolichol-19 usually the most abundant species. The team analyzed levels of dolichol species in RP sufferers compared to non-sufferers, and found, in a family of six, that the children suffering from RP had dolichol-18 as the abundant species, compared with dolichol-19 in the non-sufferers. The parents, who were each heterozygous for the mutated DHDDS gene, had intermediate dolichol-18 levels.
The profiling method developed by the team uses urine samples, since these provide a more distinct profile and are easier to obtain and store. LC–MS was used to analyze the samples; and the team hopes that this method will help personalized care of RP patients, with the ultimate aim to prevent retinal degeneration in young RP sufferers.
Although there are currently no treatments for RP, the team also hopes that this research will aid in the development of therapies for RP caused by this DHDDS mutation. Co-author Ziqiang Guan (Duke University Medical School) explained, “We are now researching ways to manipulate the dolichol synthesis pathway in RP patients with the DHDDS mutation so that the mutated enzyme can still produce enough dolichol-19, which we believe may be important for the rapid renewal of retinal tissue in a healthy individual.”
The team is currently in the process of obtaining a patent for this new diagnostic test.
