Ancestral origin of ApoE ε4 Alzheimer disease risk in Puerto Rican and African American populations.

The ApoE ε4 allele is the most significant genetic risk factor for late-onset Alzheimer disease. The risk conferred by ε4, however, differs across populations, with populations of African ancestry showing lower ε4 risk compared to those of European or Asian ancestry. The cause of this heterogeneity in risk effect is currently unknown; it may be due to environmental or cultural factors correlated with ancestry, or it may be due to genetic variation local to the ApoE region that differs among populations. Exploring these hypotheses may lead to novel, population-specific therapeutics and risk predictions. To test these hypotheses, we analyzed ApoE genotypes and genome-wide array data in individuals from African American and Puerto Rican populations. A total of 1,766 African American and 220 Puerto Rican individuals with late-onset Alzheimer disease, and 3,730 African American and 169 Puerto Rican cognitively healthy individuals (> 65 years) participated in the study. We first assessed average ancestry across the genome ("global" ancestry) and then tested it for interaction with ApoE genotypes. Next, we assessed the ancestral background of ApoE alleles ("local" ancestry) and tested if ancestry local to ApoE influenced Alzheimer disease risk while controlling for global ancestry. Measures of global ancestry showed no interaction with ApoE risk (Puerto Rican: p-value = 0.49; African American: p-value = 0.65). Conversely, ancestry local to the ApoE region showed an interaction with the ApoE ε4 allele in both populations (Puerto Rican: p-value = 0.019; African American: p-value = 0.005). ApoE ε4 alleles on an African background conferred a lower risk than those with a European ancestral background, regardless of population (Puerto Rican: OR = 1.26 on African background, OR = 4.49 on European; African American: OR = 2.34 on African background, OR = 3.05 on European background). Factors contributing to the lower risk effect in the ApoE gene ε4 allele are likely due to ancestry-specific genetic factors near ApoE rather than non-genetic ethnic, cultural, and environmental factors.

Clinical Expression of Multiple Sclerosis in Hispanic Whites of Primarily Caribbean Ancestry.

OBJECTIVE: The clinical characteristics of multiple sclerosis (MS) are not well defined in Hispanic populations. We hypothesized that disease presentation in Hispanic white (HW) patients will be different from non-Hispanic white (NHW) patients given their ancestral background and reported lower disease prevalence. This study was undertaken to compare HW of primarily Caribbean ancestry to NHW on clinical characteristics of MS. METHODS: We assessed 312 HW and 312 NHW patients with definite MS for clinical disease characteristics obtained through consented review of medical records. In order to assess the relationship between age-related phenotypes and ethnicity, linear regression was used. Logistic regression was used to assess the relationship between ethnicity and descriptors of disease presentation and severity as well as presence of neurological symptoms. RESULTS: We observed a significantly younger age at diagnosis (p = 1.38E-02) and age at exam (p = 2.36E-05) in HW. However, age at first symptom did not differ significantly between the two groups. Furthermore, within HW, the mean age at first symptom and age at diagnosis was significantly younger in those born in the United States (p < 1.00E-03 for both). Interestingly, we noted an increase in ambulatory disability in HW patients, primarily among those with relapsing disease (p = 4.18E-03). CONCLUSIONS: We found several differences in age-related phenotypes and disease severity between HW of primarily Caribbean origin and NHW patients. To our knowledge, this is the largest study to date that examined the clinical characteristics of MS in Hispanic patients of largely Caribbean origin.

Ancestral risk modification for multiple sclerosis susceptibility detected across the Major Histocompatibility Complex in a multi-ethnic population.

The Major Histocompatibility Complex (MHC) makes the largest genetic contribution to multiple sclerosis (MS) susceptibility, with 32 independent effects across the region explaining 20% of the heritability in European populations. Variation is high across populations with allele frequency differences and population-specific risk alleles identified. We sought to identify MHC-specific MS susceptibility variants and assess the effect of ancestral risk modification within 2652 Latinx and Hispanic individuals as well as 2435 Black and African American individuals. We have identified several novel susceptibility alleles which are rare in European populations including HLA-B*53:01, and we have utilized the differing linkage disequilibrium patterns inherent to these populations to identify an independent role for HLA-DRB1*15:01 and HLA-DQB1*06:02 on MS risk. We found a decrease in Native American ancestry in MS cases vs controls across the MHC, peaking near the previously identified MICB locus with a decrease of ~5.5% in Hispanics and ~0.4% in African Americans. We have identified several susceptibility variants, including within the MICB gene region, which show global ancestry risk modification and indicate ancestral differences which may be due in part to correlated environmental factors. We have also identified several susceptibility variants for which MS risk is modified by local ancestry and indicate true ancestral genetic differences; including HLA-DQB1*06:02 for which MS risk for European allele carriers is almost two times the risk for African allele carriers. These results validate the importance of investigating MS susceptibility at an ancestral level and offer insight into the epidemiology of MS phenotypic diversity.

Effectiveness of film as a health communication tool to improve perceptions and attitudes in multiple sclerosis.

BACKGROUND: Health communication tools like film are capable of reducing health disparities and could be effective in addressing negative illness perceptions of MS in Hispanics/Latinx. OBJECTIVE: To test the feasibility of using a culturally appropriate short narrative film to examine illness perceptions overtime and attitudes in Hispanics/Latinx affected with MS. METHODS: Participants were assigned to view a short narrative film (n = 130) or not (n = 106). The Brief Illness Perception Questionnaire (BIPQ) was used to examine illness perceptions at baseline, one and three months. Focus groups were conducted at 6 months. Measures of sociocultural integration were obtained. Individual group BIPQ domains were evaluated over time using paired sample t-test. Multivariate linear regression was used to examine predictors of BIPQ change. RESULTS: A more positive perception of treatment (p < 0.0001) and understanding (p = 0.0003) were seen at 3 months for those exposed to film. Focus groups were effective in highlighting that the perceived disease prognosis, family support and awareness of MS contributes to attitudes. Exposure to film was found to be the strongest predictor (Beta:6.31, p = 0.01) of BIPQ change at three months. CONCLUSION: Our results provide support that a short narrative film of MS in Hispanics/Latinx is a feasible intervention to change perceptions of MS to a more positive view.

Understanding Participation in Genetic Research Among Patients With Multiple Sclerosis: The Influences of Ethnicity, Gender, Education, and Age.

This study examined reasons for participation in a genetic study of risk for multiple sclerosis (MS). Our sample consisted of 101 patients diagnosed with MS who were approached about enrolling in the Multiple Sclerosis Genetic Susceptibility Study. Participants were predominantly Hispanic (80%), female (80%), and well educated (71%), having at least some level of college education. Of these 101 individuals who were approached, 95 agreed to participate and are the focus of this report. Among enrollees, the most frequently cited reasons for participation were to find a cure for MS (56%), having MS (46%), and helping future generations (37%). Regression models comparing ethnic groups, Hispanics endorsed having MS as a reason to participate significantly more frequently than non-Hispanics (HI 52%, non-HI 19%, p = 0.015) while non-Hispanics endorsed finding new and better treatments significantly more frequently than Hispanics (Hispanic 17%, non-Hispanic 50%, p = 0.003). Among our three age groups, younger individuals endorsed finding a cure for MS significantly more frequently (74% of 18-35-year olds vs. 56% of 36-55 year olds vs. 39% of >55 year olds). Our results suggest that motivations for participation in genetic research vary by ethnicity, and that these influences need to be considered in developing more inclusive programs of disease-related genetic research. Future efforts should focus on development of standard methods for understanding participation in genetic and genomic research, especially among underrepresented groups as a catalyst for engaging all populations.

Motivations for Participation in Parkinson Disease Genetic Research Among Hispanics versus Non-Hispanics.

Involvement of participants from different racial and ethnic groups in genomic research is vital to reducing health disparities in the precision medicine era. Racial and ethnically diverse populations are underrepresented in current genomic research, creating bias in result interpretation. Limited information is available to support motivations or barriers of these groups to participate in genomic research for late-onset, neurodegenerative disorders. To evaluate willingness for research participation, we compared motivations for participation in genetic studies among 113 Parkinson disease (PD) patients and 49 caregivers visiting the Movement Disorders clinic at the University of Miami. Hispanics and non-Hispanics were equally motivated to participate in genetic research for PD. However, Hispanic patients were less likely to be influenced by the promise of scientific advancements (N = 0.01). This lack of scientific interest, but not other motivations, was found to be likely confounded by lower levels of obtained education (N = 0.001). Overall, these results suggest that underrepresentation of Hispanics in genetic research may be partly due to reduced invitations to these studies.