A hexanucleotide repeat expansion in chromosome 9 open reading frame 72 (C9orf72) can cause amyotrophic lateral sclerosis (ALS) and/or frontotemporal dementia (FTD). We assessed its frequency in 781 sporadic ALS (sALS) and 155 familial ALS (fALS) cases, and in 248 Spanish controls. We tested the presence of the reported founder haplotype among mutation carriers and in 171 Ceph Europeans from Utah (CEU), 170 Yoruba Africans, 81 Han Chinese, and 85 Japanese subjects. The C9orf72 expansion was present in 27.1% of fALS and 3.2% of sALS. Mutation carriers showed lower age at onset (P = 0.04), shorter survival (P = 0.02), greater co‐occurrence of FTD (P = 8.2 × 10−5), and more family history of ALS (P = 1.4 × 10−20), than noncarriers. No association between alleles within the normal range and the risk of ALS was found (P = 0.12). All 61 of the mutation carriers were tested and a patient carrying 28 hexanucleotide repeats presented with the founder haplotype. This haplotype was found in 5.6% Yoruba Africans, 8.9% CEU, 3.9% Japanese, and 1.6% Han Chinese chromosomes.

This version of the HAQ-DI would allow for more availability so that Spanish-speaking countries can select the version most suitable to their sociocultural environment.

This study aimed to estimate the prevalence of musculoskeletal disorders and rheumatic diseases among the indigenous Qom (Toba) population in the city of Rosario, Santa Fe, Argentina. An analytical cross-sectional study using methodology of the Community Oriented Program for the Control of Rheumatic Diseases (COPCORD) was performed. Subjects ≥18 years of age were interviewed by advanced students of medicine and nursing, bilingual translator-facilitators, and coordinators. Individuals with musculoskeletal pain (positive cases) were evaluated sequentially for 7 days by internists and rheumatologists for diagnosis and treatment. The study included 1656 individuals (77 % of the census population). Of these, 1020 (61.5 %) were female, with mean age of 35.3 (SD 13.9) years, and 1028 (62.0 %) were bilingual. The public health care system covers 87.1 % of the population. Musculoskeletal pain in the previous 7 days and/or at some time during their life was present in 890 subjects (53.7 %). Of those with pain in the last 7 days, 302 (64.1 %) subjects had an Health Assessment Questionnaire Disability Index (HAQ-DI) score ≥0.8. The most frequent pain sites were lumbar spine (19.3 %), knees (13.0 %), and hands (12.0 %). The prevalence of rheumatic diseases was as follows: mechanical back pain (20.1 %), rheumatic regional pain syndrome (2.9 %), osteoarthritis (4.0 %) rheumatoid arthritis (2.4 %), inflammatory back pain (0.2 %), systemic sclerosis (0.1 %), Sjögren syndrome (0.1 %), fibromyalgia (0.1 %), mixed connective tissue disease (0.06 %), and systemic lupus erythematosus (0.06 %). The prevalence of musculoskeletal disorders was 53.7 % and rheumatic diseases 29.6 %. Rheumatoid arthritis prevalence was 2.4 % using COPCORD methodology, one of the highest reported at present.

The purpose of the study is to validate a culturally sensitive adaptation of the community-oriented program for the control of rheumatic diseases (COPCORD) methodology in several Latin American indigenous populations. The COPCORD Spanish questionnaire was translated and back-translated into seven indigenous languages: Warao, Kariña and Chaima (Venezuela), Mixteco, Maya-Yucateco and Raramuri (Mexico) and Qom (Argentina). The questionnaire was administered to almost 100 subjects in each community with the assistance of bilingual translators. Individuals with pain, stiffness or swelling in any part of the body in the previous 7 days and/or at any point in life were evaluated by physicians to confirm a diagnosis according to criteria for rheumatic diseases. Overall, individuals did not understand the use of a 0-10 visual analog scale for pain intensity and severity grading and preferred a Likert scale comprising four items for pain intensity (no pain, minimal pain, strong pain, and intense pain). They were unable to discriminate between pain intensity and pain severity, so only pain intensity was included. For validation, 702 subjects (286 male, 416 female, mean age 42.7 ± 18.3 years) were interviewed in their own language. In the last 7 days, 198 (28.2 %) subjects reported having musculoskeletal pain, and 90 (45.4 %) of these had intense pain. Compared with the physician-confirmed diagnosis, the COPCORD questionnaire had 73.8 % sensitivity, 72.9 % specificity, a positive likelihood ratio of 2.7 and area under the receiver operating characteristic curve of 0.73. The COPCORD questionnaire is a valid screening tool for rheumatic diseases in indigenous Latin American populations.

Epidemiological studies in Latin America suggest indigenous people lack proper healthcare for musculoskeletal (MSK) and rheumatic diseases.ObjectivesThis study aimed to estimate the prevalence of MSK disorders and rheumatic diseases in eight Latin American indigenous communities, and to identify which factors influence such prevalence using network analysis and syndemic approach.MethodsThis is a cross-sectional, community-based census study according to Community-Oriented Program for the Control of Rheumatic Diseases methodology. Individuals with MSK pain, stiffness or swelling in the past and/or during the last 7 days were evaluated by participating physicians. A descriptive, univariable and multivariable analysis was performed, followed by a network analysis.ResultsWe surveyed 6155 indigenous individuals with a mean age of 41.2 years (SD 17.6; range 18–105); 3757 (61.0%) were women. Point prevalence in rank order was: low back pain in 821 (13.3%); osteoarthritis in 598 (9.7%); rheumatic regional pain syndromes in 368 (5.9%); rheumatoid arthritis in 85 (1.3%); undifferentiated arthritis in 13 (0.2%); and spondyloarthritis in 12 (0.1%). There were marked variations in the prevalence of each rheumatic disease among the communities. Multivariate models and network analysis revealed a complex relationship between rheumatic diseases, comorbidities and socioeconomic conditions.ConclusionsThe overall prevalence of MSK disorders in Latin American indigenous communities was 34.5%. Although low back pain and osteoarthritis were the most prevalent rheumatic diseases, wide variations according to population groups occurred. The relationship between rheumatic diseases, comorbidities and socioeconomic conditions allows taking a syndemic approach to the study.