RHO Variants and Autosomal Dominant Retinitis Pigmentosa: Insights from the Italian Genetic Landscape

Autosomal dominant retinitis pigmentosa (AD-RP) is caused by several genes, among which <i>RHO</i> is one of the most investigated. This article will be focused on <i>RHO</i> and its role in explaining AD-RP cases in the Italian population, taking advantage of the experience of the Genomic Medicine Laboratory UILDM at the Santa Lucia Foundation IRCCS. The retrospective evaluation of the distribution of <i>RHO</i> variants in the Italian patients with a clinical suspicion of RP pointed out eight variants. Of them, four variants (c.632A>T, c.1040C>T, c.1030C>T, c.383_392del) were pathogenic and made it possible to confirm the diagnosis of AD-RP in nine affected patients, highlighting a lower frequency (17%) of <i>RHO</i> variants compared to previous studies (30-40%). In addition, this study identified four variants classified as Variants of Uncertain Significance (VUS). In conclusion, the experience of the Genomic Medicine Laboratory provides an overview of the distribution of <i>RHO</i> variants in the Italian population, highlighting a slightly lower frequency of these variants in our cases series compared to previous reports. However, further studies on <i>RHO</i> variants are essential to characterize peculiar RP phenotypes and extend the spectrum of disease associated with this gene.