Dispersed DNA variants underlie hearing loss in South Florida's minority population

Abstract

Background: We analyzed the genetic causes of sensorineural hearing loss in racial and ethnic minorities of South Florida by reviewing demographic, phenotypic, and genetic data on 136 patients presenting to the Hereditary Hearing Loss Clinic at the University of Miami. In our retrospective chart review, of these patients, half self-identified as Hispanic, and the self-identified racial distribution was 115 (86%) White, 15 (11%) Black, and 6 (4%) Asian. Our analysis helps to reduce the gap in understanding the prevalence, impact, and genetic factors related to hearing loss among diverse populations.

Results: The causative gene variant or variants were identified in 54 (40%) patients, with no significant difference in the molecular diagnostic rate between Hispanics and Non-Hispanics. However, the total solve rate based on race was 40%, 47%, and 17% in Whites, Blacks, and Asians, respectively. In Non-Hispanic Whites, 16 different variants were identified in 13 genes, with GJB2 (32%), MYO7A (11%), and SLC26A4 (11%) being the most frequently implicated genes. In White Hispanics, 34 variants were identified in 20 genes, with GJB2 (22%), MYO7A (7%), and STRC-CATSPER2 (7%) being the most common. In the Non-Hispanic Black cohort, the gene distribution was evenly dispersed, with 11 variants occurring in 7 genes, and no variant was identified in 3 Hispanic Black probands. For the Asian cohort, only one gene variant was found out of 6 patients.

Conclusion: This study demonstrates that the diagnostic rate of genetic studies in hearing loss varies according to race in South Florida, with more heterogeneity in racial and ethnic minorities. Further studies to delineate deafness gene variants in underrepresented populations, such as African Americans/Blacks from Hispanic groups, are much needed to reduce racial and ethnic disparities in genetic diagnoses.

Keywords: Gene variants; Genetic; Minority; Multicultural; Racial and ethnic; Sensorineural hearing loss.

Fig. 1

Causal Gene Distribution According to Racial and Ethnic Groups. A Exhibits the gene distribution in the solved White Non-Hispanic population. B Exhibits the gene distribution in the solved White Hispanic population. C Exhibits the gene distribution in the solved Non-Hispanic Black/African American population

Fig. 2

Solve Rate Analysis of Hearing Loss in a Multicultural Population. Solve Rate Analysis of ethnicity, race, phenotype, and family history of the Total, Non-Hispanic and Hispanic cohort. (The percentages are representative of the solve rate. i.e. Asian cohort has a 17% SR, of these if late onset HL the SR increases to 50%, when mild to moderate severity HL also present the SR remains at 50%, when bilateral HL also present the SR also remains at 50%, when the case is also syndromic the SR increases to 100% and remains at a 100% SR if no family history)