Objective. This study aims to generate evidence on intellectual development disorders (IDD) in Mexico. Materials and methods. IDD disease burden will be estimated with a probabilistic model, using population-based surveys. Direct and indirect costs of catastrophic expenses of families with a member with an IDD will be evaluated. Genomic characterization of IDD will include: sequencing participant exomes and performing bioinformatics analyses to identify de novo or inherited variants through trio analysis; identifying genetic variants associated with IDD, and validating randomly selected variants by polymerase chain reaction (PCR) and sequencing or real-time quantitative PCR (qPCR). Delphi surveys will be done on best practices for IDD diagnosis and management. An external evaluation will employ qualitative case studies of two social and labor inclusion programs for people with IDD. Conclusions. The results will constitute scientific evidence for the design, promotion and evaluation of public policies, which are currently absent on IDD.

Introduction: There are reports of different clinical statuses in carriers of intermediate alleles (IAs) of CAG trinucleotide repeats in the HTT gene, from individuals affected by a clinical picture indistinguishable from Huntington’s disease (HD) to those without manifestations. Therefore, the possible clinical significance of these alleles has been widely debated. Objectives: The aim of this study was to describe general and clinical features and discard HD phenocopies by molecular assessment in a case series of IA carriers on the HTT gene of a laboratory sample from a neurological center in Mexico. Methods: We selected individuals who had previously been tested for the HTT gene expansion, which resulted in IAs. Clinical information was obtained from medical records, and molecular analysis of the JPH3, PRNP, and TBP genes was performed only in IA carriers with clinical manifestations. In addition, two patients with IA and acanthocytes were evaluated by whole-exome sequencing. The scientific and ethical committees of the National Institute of Neurology and Neurosurgery Manuel Velasco Suárez (NINNMVS) approved this study. Results: From 1994 to 2019, the Genetics Department of the NINNMVS confirmed 34 individuals with IAs, 15 of whom belonged to 11 families with HD (IA-HD) and 19 of whom had no family history of HD (IA-non-HD). We found a high proportion of manifestations of the HD phenotypic spectrum in the IA-non-HD subgroup. In addition, among the 20 samples of IA carriers with manifestations molecularly evaluated, we identified two unrelated subjects with CAG/CTG repeat expansions on the JPH3 gene, confirming HD-like 2 (HDL2), and one patient with the homozygous pathogenic c.3232G>T variant (p.Glu1078Ter) in the VPS13A gene, demonstrating choreoacanthocytosis. Discussion/Conclusion: Our results show the most extensive series of subjects with IAs and clinical manifestations. In addition, we identify three HD phenocopies, two HDL2 cases, and one choreoacanthocytosis case. Therefore, we emphasize evaluating other HD phenocopies in IA carriers with clinical manifestations whose family background is not associated with HD.

Leukodystrophies comprise a spectrum of genetic disorders affecting white matter (WM) formation in the central nervous system (CNS), of which vanishing white matter disease (VWMD) is one. VWMD presents with progressive neurological deterioration and a variety of manifestations. Ovarioleukodystrophy, a subtype of VWMD, exhibits a distinctive clinical profile encompassing both CNS WM alterations and ovarian dysfunction. Variants in genes of the eukaryotic translation initiation factor 2B (EIF2B) complex affect the full form and are implicated in VWMD, including ovarioleukodystrophy. This work aimed to systematically review all published cases of ovarioleukodystrophy associated with variants in the EIF2B1-5 gene complex based on the first case identified in a Mexican population. We performed a systematic review according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines of published cases of ovarioleukodystrophy associated with the EIF2B gene complex, including a newly identified case from Mexico. We identified 207 publications using PUBMED, SCOPUS, and PMC databases. One hundred fifty-one publications were eliminated due to duplicates, titles, abstracts, or other reasons, while 56 publications were revised, of which 29 were eliminated because they dealt with other genes or non-human research, and 27 reports were assessed for eligibility. Finally, 14 reports describing ovarian involvement, neuroimaging, and molecular variants were included. Our review identified 20 cases worldwide, with a median age of onset of 19 years. Clinical features included WM involvement, ovarian abnormalities, gait disturbances, epilepsy, cognitive and language impairment, and other neurological manifestations. Neuroimaging showed characteristic WM changes, highlighting the importance of MRI in diagnosis. Missense variants predominated among the identified genetic mutations, especially in the EIF2B4 and EIF2B5 genes. Ovarioleukodystrophy is an ultra-rare disorder with a wide range of clinical manifestations and ovarian changes. Gynecological evaluation is crucial in suspected cases of ovarioleukodystrophy, as ovarian manifestations may precede neurological symptoms. The role of MRI is crucial in the diagnostic approach to this entity. Continued collaborative efforts are essential to elucidate genotype-phenotype correlations, improve clinical management, and promote therapeutic advances for this rare disorder.

Background: Parkinson's disease (PD) is a progressive neurodegenerative disorder that negatively affects the well-being of both patients and their caregivers. Therefore, the aim of the present study was to identify factors associated with quality of life (QoL) in patients with Parkinson's disease (PPD) and caregiver burden in their primary caregivers (PCG). Methods: We conducted a cross-sectional study at a tertiary neurological center in Mexico. Assessments included the Parkinson's Disease Questionnaire (PDQ-39); motor severity with the Movement Disorder Society–Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III); cognition with the Montreal Cognitive Assessment (MoCA); depressive and anxiety symptoms with the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 (GAD-7); and internalized stigma with the King Internalized Stigma Scale (ISS). Caregiver burden was measured with the Zarit Burden Interview (ZBI). Results: We included 48 PPD (58.3% male) and 38 PCG (55.3% female). Mean disease duration was 7.3 years [standard deviations (SD) = 4.6; range 1–26 years]. Among PPD, 97.9% were on dopaminergic replacement therapy and 43.8% reported comorbidities. Anxiety severity differed between groups (χ2 = 11.7, p = 0.008). No between-group differences were observed in internalized stigma (ISS total score and subdomains). A significant discrepancy emerged regarding assistance with activities of daily living (ADLs), reported by 63.2% of PCG versus 20.8% of PPD (p < 0.001). Linear regression models showed that poorer QoL in PPD was associated with depressive and anxiety symptoms and motor severity (MDS-UPDRS III) (R2 = 0.47). Caregiver burden in PCG was associated with depressive symptoms and perceived discrimination (ISS subdomain) (R2 = 0.53). Conclusions: Comprehensive PD management, beyond motor control, should incorporate the evaluation and support of mental health, alongside stigma-reduction strategies, to enhance the well-being of both PPD and their PCG.