Publications by authors named "Sandra Romero-Hidalgo"

Searching for positive selection signals across genomes has identified functional genetic variants responding to environmental change. In Native Americans of Mexico, we used the fixation index (F) and population branch statistic (PBS) to identify SNPs suggesting positive selection. The 103 most differentiated SNPs were tested for associations with metabolic traits, the most significant association was /rs174616 with body mass index (BMI).

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  • The study investigates the variability in clinical symptoms of dilated cardiomyopathy (DCM) among individuals with the same genetic mutation affecting lamin AC and LAP2α proteins.
  • *Researchers identified a DCM patient with both a lamin AC mutation and a common LAP2α polymorphism, highlighting their potential combined effects on the disease.
  • *Advanced modeling and microscopy revealed that the LAP2α polymorphism alters nuclear shapes, indicating it might influence disease severity and symptom expression in dilated cardiomyopathy.
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Episodic memory allows us to remember three main elements regarding an event: what (it is), where (it is in space), and when (it appears). The brain's electrical activity signaling the occurrence of these processes has been studied separately, revealing different patterns of ERP components and changes in the EEG theta band amplitude. However, how these patterns signal the retrieval of the temporal and spatial contexts of the same episode is unknown.

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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.

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Neuromyelitis Optica Spectrum Disorder (NMOSD) is a demyelinating autoimmune disease of the central nervous system, more prevalent in individuals of non-European ancestry. Few studies have analyzed genetic risk factors in NMOSD, and HLA class II gene variation has been associated NMOSD risk in various populations including Mexicans. Thymopoietin () has not been tested as a candidate gene for NMOSD or other autoimmune disease, however, experimental evidence suggests this gene may be involved in negative selection of autoreactive T cells and autoimmunity.

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  • A study was conducted to find genetic variants linked to low HDL-C levels in Mexicans, identifying four significant loci, including a notable variant in the SIDT2 gene.
  • The SIDT2/Val636Ile variant is more common in Native American populations and is associated with improved cholesterol levels and a lower risk of premature coronary artery disease.
  • The findings suggest that SIDT2 plays a crucial role in cholesterol metabolism, providing new insights into the genetics of HDL-C and its relationship to heart health in the Mexican population.
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Attention and working memory (WM) are under high genetic regulation. Single nucleotide polymorphisms (SNPs) of the CNR1 gene, that encode for CB1R, have previously been shown to be related with individual differences in attentional control and WM. However, it remains unclear whether there is an allele-dosage or a dominant contribution of polymorphisms of CNR1 affecting attention and WM performance.

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Background: Fukuyama congenital muscular dystrophy (FCMD) is the most common form of a group of autosomal recessive disorders characterized by altered α-dystroglycan glycosylation and caused by FKTN gene mutations. However, mutations of this gene may cause a broad range of phenotypes, including Walker-Warburg syndrome, muscle-brain-eye disease, FCMD, limbgirdle muscular dystrophy without mental retardation, and cardiomyopathy with no or minimal skeletal muscle weakness.

Objective: Our purpose was to describe two siblings who died at a young age with dilated cardiomyopathy (DCM), no muscle weakness, or atrophy, and were homozygous for a FKTN missense mutation.

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  • Dilated cardiomyopathy (DCM) is a leading cause of heart failure in young adults, and next generation sequencing (NGS) has been used to diagnose idiopathic and familial DCM, although challenges remain in underrepresented populations.
  • A study involving 55 Mexican DCM patients found an overall diagnostic yield of 47.3%, higher for familial cases (63.6%) compared to idiopathic cases (36.4%), with many identified variants being novel.
  • This study is significant as it's the first of its kind in Mexico, enhancing the understanding of the genetic variations associated with DCM in this population and paving the way for better diagnosis and treatment strategies.
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Neuromyelitis Optica (NMO) is an autoimmune disease with a higher prevalence in non-European populations. Because the Mexican population resulted from the admixture between mainly Native American and European populations, we used genome-wide microarray, HLA high-resolution typing and AQP4 gene sequencing data to analyze genetic ancestry and to seek genetic variants conferring NMO susceptibility in admixed Mexican patients. A total of 164 Mexican NMO patients and 1,208 controls were included.

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We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) allele groups and alleles by PCR-SSP based typing in a total of 15,318 mixed ancestry Mexicans from all the states of the country divided into 78 sample sets, providing information regarding allelic and haplotypic frequencies and their linkage disequilibrium, as well as admixture estimates and genetic substructure. We identified the presence of 4268 unique HLA extended haplotypes across Mexico and find that the ten most frequent (HF > 1%) HLA haplotypes with significant linkage disequilibrium (Δ'≥0.1) in Mexico (accounting for 20% of the haplotypic diversity of the country) are of primarily Native American ancestry (A*02~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*08~DQB1*04, A*68~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*14~DQB1*03:01, A*24~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*04~DQB1*03:02, A*02~B*40:02~DRB1*04~DQB1*03:02, A*68~B*35~DRB1*04~DQB1*03:02, A*02~B*15:01~DRB1*04~DQB1*03:02).

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  • Hyperuricemia risk is influenced by both genetic and environmental factors, and this study focuses on identifying those factors in a Mexican population.
  • A pilot genome-wide association study (GWAS) analyzed data from 411 participants, leading to the identification of four significant SNPs linked to serum uric acid levels, which were confirmed in larger groups.
  • Non-genetic factors such as visceral fat, smoking, and metabolic syndrome components were associated with higher uric acid levels, with increased soft drink consumption raising hyperuricemia odds in women, highlighting the roles of diet and genetics in the condition's prevalence in Mexico.
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  • The study investigates the relationship between serum uric acid (SUA) levels and cardiovascular disease risk in a Mexican population, as previous research has primarily focused on Europeans.
  • It identifies two genetic loci, SLC2A9 and ABCG2, linked to SUA levels but finds no significant interaction with obesity, though a notable sex difference in adults was observed.
  • The results suggest that while elevated SUA is correlated with premature coronary artery disease and related health issues, the genetic variants studied do not indicate a direct causal relationship with premature CAD.
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Understanding the genetic structure of Native American populations is important to clarify their diversity, demographic history, and to identify genetic factors relevant for biomedical traits. Here, we show a demographic history reconstruction from 12 Native American whole genomes belonging to six distinct ethnic groups representing the three main described genetic clusters of Mexico (Northern, Southern, and Maya). Effective population size estimates of all Native American groups remained below 2,000 individuals for up to 10,000 years ago.

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  • The study investigated the prevalence of Metabolic Syndrome (MetS) and its associated factors in the elderly population of Mexico, finding a high prevalence of 72.9%.
  • A sample of 516 elderly individuals (≥65 years) was analyzed, highlighting significant markers of MetS like hypertension (92.4%) and hyperglycemia (71.1%).
  • The results indicated that education level, smoking status, and geographic location in Mexico influenced the prevalence and components of MetS, with BMI being the key determinant.
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To identify genetic variants influencing bone mineral density (BMD) in the Mexican-Mestizo population, we performed a GWAS for femoral neck (FN) and lumbar spine (LS) in Mexican-Mestizo postmenopausal women. In the discovery sample, 300,000 SNPs were genotyped in a cohort of 411 postmenopausal women and seven SNPs were analyzed in the replication cohort ( = 420). The combined results of a meta-analysis from the discovery and replication samples identified two loci, (rs6904364, = 2.

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Background: The aim of this study was to explore whether interactions between FTO rs9939609 and ABCA1 rs9282541 affect BMI and waist circumference (WC), and could explain previously reported population differences in FTO-obesity and FTO-BMI associations in the Mexican and European populations.

Methods: A total of 3938 adults and 636 school-aged children from Central Mexico were genotyped for both polymorphisms. Subcutaneous and visceral adipose tissue biopsies from 22 class III obesity patients were analyzed for FTO and ABCA1 mRNA expression.

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Obesity is a major public health concern in Mexico and worldwide. Although the estimated heritability is high, common variants identified by genome-wide association studies explain only a small proportion of this heritability. A combination of linkage and association strategies could be a more robust and powerful approach to identify other obesity-susceptibility variants.

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Individual differences in working memory ability are mainly revealed when a demanding challenge is imposed. Here, we have associated cannabinoid 1 (CB1) receptor genetic variation rs2180619 (AA, AG, GG), which is located in a potential CNR1 regulatory sequence, with performance in working memory. Two-hundred and nine Mexican-mestizo healthy young participants (89 women, 120 men, mean age: 23.

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Background: Although the R230C-ATP-binding cassette A1 (ABCA1) variant has been consistently associated with HDL-C levels, its association with diabetes and other metabolic parameters is unclear. Estrogen and dietary factors are known to regulate ABCA1 expression in different tissues. Thus, we aimed to explore whether gender, menopausal status and macronutrient proportions of diet modulate the effect of this variant on various metabolic parameters.

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Objective: Irisin is a novel myokine that seems to mediate the beneficial effects of exercise. Levels of circulating irisin before and after an 8-month physical activity program (PAP) in school-age children were evaluated.

Methods: Irisin and leptin were measured at baseline and at follow-up among 85 children with different BMI.

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Mexico harbors great cultural and ethnic diversity, yet fine-scale patterns of human genome-wide variation from this region remain largely uncharacterized. We studied genomic variation within Mexico from over 1000 individuals representing 20 indigenous and 11 mestizo populations. We found striking genetic stratification among indigenous populations within Mexico at varying degrees of geographic isolation.

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The patatin like phospholipase domain-containing (PNPLA3) I148M variant is the strongest genetic factor associated with elevated alanine transaminase (ALT) levels in different populations, particularly in Hispanics who have the highest 148M risk allele frequency reported to date. It has been suggested that Indigenous ancestry is associated with higher ALT levels in Mexicans. The aim of the present study was to assess the frequency of the PNPLA3 148M risk allele in Mexican indigenous and Mestizo individuals, and to examine its association with serum ALT levels.

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Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disease characterized by progressive cerebellar ataxia and macular degeneration causing progressive blindness. It accounts for 1 to 11.6 % of spinocerebellar ataxias (SCAs) cases worldwide and for 7.

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Background: Several studies have identified multiple obesity-associated loci mainly in European populations. However, their contribution to obesity in other ethnicities such as Mexicans is largely unknown. The aim of this study was to examine 26 obesity-associated single-nucleotide polymorphisms (SNP) in a sample of Mexican mestizos.

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