Andrea Rivera- Valdivia

La distrofia miotónica tipo 1 (DM1) es una enfermedad neuromuscular hereditaria autosómica dominante de carácter sistémico, caracterizada por debilidad muscular progresiva, miotonía y cataratas. Además, puede comprometer los sistemas cardiovascular, endocrino y nervioso central. En este reporte presentamos tres casos de DM1 con afectación significativa del sistema nervioso central, evidenciada por alteraciones estructurales en imágenes de resonancia magnética cerebral, deterioro cognitivo, epilepsia y cambios conductuales. Se destaca la importancia de una evaluación multidisciplinaria que integre valoraciones neuropsiquiátricas y estudios de neuroimagen como parte esencial del manejo integral de esta afección.

Spinocerebellar ataxia type 10 (SCA10) is an autosomal-dominant disorder caused by intronic expansions of pentanucleotide repeats in the ATXN10 gene. While various repeat motifs have been described, emerging evidence suggests that specific repeat motifs, rather than repeat length alone, can modify disease features such as seizure prevalence and penetrance. We used a novel multiplex 20-gene panel with Cas9-targeted, amplification-free long-read sequencing (LRS) and optical genome mapping to elucidate ATXN10 repeat motif patterns and investigated genotype-phenotype correlations in index cases of 6 multigenerational SCA10 kindreds from Peru. We detected ATXN10 repeat expansions ranging from 990 to 2,002 pentanucleotide repeats (4.9–10 kb) across 6 families. It is important to note that we identified 3 mixed repeat motif patterns and ratios of (ATTCT)_n(ATTCC)_n, which were associated with differences in age at disease onset and anticipation. Our key novel finding is the prominence of the alternate ATTCC motif alongside the common ATTCT motif. While repeat length alone does not appear to drive disease onset in SCA10, we uncovered that the ratio of the ATTCC motif within distinct repeat patterns might correlate with disease onset. These findings underscore the need to adapt LRS clinical workflows to fully characterize large repeat expansions at the nucleotide level.

Background: The global prevalence of Parkinson's disease (PD) is estimated to be 315 per 100,000 inhabitants, with variations across regions and depending on the epidemiological methods used. Door‐to‐door prevalence studies in Andean communities are notably underrepresented in the literature. Objective: The aim of this study was to estimate the PD prevalence in Jauja. Methods: A cross‐sectional community‐based door‐to‐door prevalence study was conducted from April 2018 to September 2019. We used a Spanish version of the 9‐item screening questionnaire (9‐item SQ). Trained interviewers conducted face‐to‐face screening surveys. Participants presenting “suspected parkinsonism” underwent further neurological assessment. PD cases responded to the LARGE‐PD questionnaire and “pesticide exposure questionnaire.” We calculated the crude prevalence, gender‐ and age‐specific rates, and age‐adjusted rates. Results: Out of 2527 eligible individuals, 1960 completed the screening survey. Of these, 563 were selected for neurological assessment, and 337 underwent neurological examination. PD was confirmed in 21 individuals, 16 of whom were identified using the 9‐item SQ with a crude prevalence of 816/100,000. We observed higher rates of PD in older age groups and in males compared to females (1.6 vs. 0.3%, P < 0.05). The age‐standardized prevalence was 566/100,000 (95% confidence interval [CI]: 496.6–635.2). Among PD cases, the most common environmental exposures were living near farming fields and pesticide exposure. Conclusions: The observed prevalence of PD in this town in the central highlands of Peru aligns with previous reports, with notably higher rates among individuals over the age of 80. Further prospective studies are warranted to investigate the potential influence of environmental factors on PD prevalence in this region.