Evaluating genetic ancestry and self-reported ethnicity in the context of carrier screening.

BACKGROUND: Current professional society guidelines recommend genetic carrier screening be offered on the basis of ethnicity, or when using expanded carrier screening panels, they recommend to compute residual risk based on ethnicity. We investigated the reliability of self-reported ethnicity in 9138 subjects referred to carrier screening. Self-reported ethnicity gathered from test requisition forms and during post-test genetic counseling, and genetic ancestry predicted by a statistical model, were compared for concordance. RESULTS: We identified several discrepancies between the two sources of self-reported ethnicity and genetic ancestry. Only 30.3% of individuals who indicated Mediterranean ancestry during consultation self-reported this on requisition forms. Additionally, the proportion of individuals who reported Southeast Asian but were estimated to have a different genetic ancestry was found to depend on the source of self-report. Finally, individuals who reported Latin American demonstrated a high degree of ancestral admixture. As a result, carrier rates and residual risks provided for patient decision-making are impacted if using self-reported ethnicity. CONCLUSION: Our analysis highlights the unreliability of ethnicity classification based on patient self-reports. We recommend the routine use of pan-ethnic carrier screening panels in reproductive medicine. Furthermore, the use of an ancestry model would allow better estimation of carrier rates and residual risks.

Translation and validation of a Spanish-language genetic health literacy screening tool.

OBJECTIVE: Literacy deficits and underutilization of medical services have been linked to health disparities among minorities, and this appears especially relevant for the Latino population. Given the increasing importance of genetics, assessment of genetic health literacy may direct future efforts to better serve this vulnerable population. The current study was designed to contribute to this area by translating and validating a Spanish-language genetic health literacy measure. METHOD: This was a cross-sectional study involving an interviewer-administered questionnaire. Eligible individuals were Latinos between the ages of 18 and 75 residing in Maryland, who self-reported Spanish as their primary language, recruited through convenience sampling. The genetic health literacy measure components were adapted from existing English-language measures [Erby, Roter, Larson, & Cho's (2008) Rapid Estimate of Adult Literacy in Genetics (REAL-G) and Hooker et al.'s (2014) Genetic Literacy and Comprehension]. An existing Spanish-language general health literacy measure was used to establish preliminary concurrent validity [Lee, Bender, Ruiz, & Cho's (2006) SAHLSA]. RESULTS: 116 individuals completed the assessment. The Spanish-language REAL-G (REAL-G-Sp) was found to correlate well with the SAHLSA (Pearson's r = .77, p < .01). A cut-off score of 59 (out of 62) distinguished low versus high genetic health literacy with a sensitivity of 86% and specificity of 71%, identifying 28% of participants as having inadequate genetic health literacy. CONCLUSIONS: The REAL-G-Sp was found to have preliminary concurrent validity with an existing health literacy measure in the Latino population residing in Maryland. Significant proportions of this population are predicted to have limitations in genetic health literacy, even when information is provided in Spanish.