Outcomes of genetic testing for Usher syndrome in a diverse population cohort from South Florida.

backgroundUsher syndrome (USH) is the leading genetic cause of congenital deaf blindness worldwide. USH is an autosomal recessive disorder clinically characterized by partial or complete congenital sensorineural hearing loss followed by progressive vision loss due to retinitis pigmentosa. There are three main subtypes (USH1, USH2, USH3) with different genetic causes categorized by age of symptom onset and severity. Understanding the genetic epidemiology of USH can help identify novel mutations and facilitate definitive diagnosis and treatment. This retrospective study characterizes the mutation spectrum of USH in an ethnically diverse South Florida population.

resultsOf the 148 patients assessed for this study, 67 were male and 81 were female. In this population, one identified as American Indian or Alaska Native, 6 identified as Asian (A), eight identified as Black or African American (AA), eight identified as More than One Race, 26 were identified as Unknown or Not Reported, and 99 were identified as white. In addition, 42 identified as Hispanic or Latino, 87 identified as Non-Hispanic or Latino, and 19 were identified as Unknown or Not Reported; all individuals identifying as Hispanic or Latino were either White or Unknown. One American Indian or Alaska Native patient, two Asian patients, two Black or African American Patients, and 15 white patients had inconclusive molecular testing results. In our population, White Non-Hispanics were more likely to receive a conclusive molecular diagnosis for their hearing loss.

conclusionsThis is the first genetic characterization of an ethnically diverse South Florida population with USH, which can help direct patient diagnosis and medical care. As clinical trials for treatment increases, molecular testing in all individuals is imperative.