Mutational spectrum and genotype-phenotype correlation in Mexican patients with infantile-onset and late-onset Pompe disease.

BACKGROUND: Pompe Disease (PD) is a metabolic myopathy caused by variants in the GAA gene, resulting in deficient enzymatic activity. We aimed to characterize the clinical features and related genetic variants in a series of Mexican patients. METHODS: We performed a retrospective study of clinical records of patients diagnosed with LOPD, IOPD or pseudodeficiency. RESULTS: Twenty-nine patients were included in the study, comprising these three forms. Overall, age of symptom onset was 0.1 to 43 years old. The most frequent variant identified was c.-32-13T>G, which was detected in 14 alleles. Among the 23 different variants identified in the GAA gene, 14 were classified as pathogenic, 5 were likely pathogenic, and 1 was a variant of uncertain significance. Two variants were inherited in cis arrangement and 2 were pseudodeficiency-related benign alleles. We identified two novel variants (c.1615 G>A and c.1076-20_1076-4delAAGTCGGCGTTGGCCTG). CONCLUSION: To the best of our knowledge, this series represent the largest phenotypic and genotypic characterization of patients with PD in Mexico. Patients within our series exhibited a combination of LOPD and IOPD associated variants, which may be related to genetic diversity within Mexican population. Further population-wide studies are required to better characterize the incidence of this disease in Mexican population.

IFITM5-related (type V) osteogenesis imperfecta with evidence of perinatal involvement: A case report.

Osteogenesis imperfecta (OI) is a rare hereditary disorder characterized by bone fragility and frequent fractures. While most cases are attributed to variations in collagen-coding genes COL1A1 and COL1A2, other genes such as IFITM5 have also been associated with the disease, accounting for up to 5 % of cases. Here, we report a case of a 3-month-old female with a femur fracture and limb deformity. X-rays revealed evidence of osteopenia and previous fractures in the arms, clavicle, ribs, and left limb, alongside prenatal bone deformities detected by ultrasound. Initial clinical evaluation suggested progressively deforming (Sillence's type III) osteogenesis imperfecta (OI). Molecular testing led to the diagnosis of IFITM5-related OI, identifying the c.-14C>T (rs587776916) variant. Although this variant has been previously reported in patients with IFITM5-related OI, prenatal involvement had not been associated with this variant.

Infantile-onset Pompe disease in seven Mexican children.

INTRODUCTION: Pompe disease (PD) is a rare form of metabolic myopathy; the classic infantile presentation is severe, with death occurring before reaching one year of life, and the non-classical form is of slower progression and survival can exceed one year. OBJECTIVE: To describe the genotype and characteristics of Mexican patients with infantile-onset PD. METHODS: Seven patients with PD confirmed by enzymatic activity determination and GAA gene molecular analysis were included. Mutations were reviewed in genomic databases. RESULTS: Median age at symptom onset was four months (1-12 months) and age at diagnosis was eight months (4-16 months). All patients had cardiomyopathy: four who died before one year of age had mutations that predicted severe disease (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) and were negative for cross-reactive immunologic material (CRIM). Three patients survived after one year of age with enzyme replacement therapy; one survived almost five years, another 18 months, and one girl was almost three years of age at the time of this report; their pathogenic variants predicted potentially less severe disease (c.1979G>A, c.655G>A, c.1447G>A) and they were positive for CRIM. CONCLUSION: There was a good correlation between genotype and phenotype in children with Pompe disease.

INTRODUCCIÓN: La enfermedad de Pompe (EP) es una forma rara de miopatía metabólica; la presentación infantil clásica es severa y el fallecimiento acontece antes del año de vida, y la forma no clásica es de progresión más lenta y la sobrevivencia puede superar el año. OBJETIVO: Describir genotipo y características de pacientes mexicanos con EP de inicio infantil. MÉTODOS: Se incluyeron siete pacientes con enfermedad confirmada mediante actividad enzimática y estudio molecular del gen GAA. Se revisaron las mutaciones en bases de datos genómicas. RESULTADOS: La mediana de la edad de inicio de los síntomas fue de cuatro meses (1-12 meses) y la edad de diagnóstico fue de ocho meses (4-16 meses). Todos los pacientes tenían cardiomiopatía: cuatro que fallecieron antes del año presentaron mutaciones que predicen enfermedad severa (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) y CRIM (cross-reactive immunologic material) negativo; tres sobrevivieron después del año de edad con terapia de reemplazo enzimático, uno casi cinco años, otro 18 meses y una niña tenía casi tres años al momento de este informe; sus variantes patogénicas predecían enfermedad potencialmente menos severa (c.1979G>A, c.655G>A, c.1447G>A) y CRIM positivo. CONCLUSIÓN: Existió buena correlación entre genotipo y fenotipo en niños con enfermedad de Pompe.

Enfermedad de Pompe de inicio infantil en siete niños mexicanos / Infantile-onset Pompe disease in seven Mexican children

Resumen Introducción: La enfermedad de Pompe (EP) es una forma rara de miopatía metabólica; la presentación infantil clásica es severa y el fallecimiento acontece antes del año de vida, y la forma no clásica es de progresión más lenta y la sobrevivencia puede superar el año. Objetivo: Describir genotipo y características de pacientes mexicanos con EP de inicio infantil. Métodos: Se incluyeron siete pacientes con enfermedad confirmada mediante actividad enzimática y estudio molecular del gen GAA. Se revisaron las mutaciones en bases de datos genómicas. Resultados: La mediana de la edad de inicio de los síntomas fue de cuatro meses (1-12 meses) y la edad de diagnóstico fue de ocho meses (4-16 meses). Todos los pacientes tenían cardiomiopatía: cuatro que fallecieron antes del año presentaron mutaciones que predicen enfermedad severa (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) y CRIM (cross-reactive immunologic material) negativo; tres sobrevivieron después del año de edad con terapia de reemplazo enzimático, uno casi cinco años, otro 18 meses y una niña tenía casi tres años al momento de este informe; sus variantes patogénicas predecían enfermedad potencialmente menos severa (c.1979G>A, c.655G>A, c.1447G>A) y CRIM positivo. Conclusión: Existió buena correlación entre genotipo y fenotipo en niños con enfermedad de Pompe.

Abstract Introduction: Pompe disease (PD) is a rare form of metabolic myopathy; the classic infantile presentation is severe, with death occurring before reaching one year of life, and the non-classical form is of slower progression and survival can exceed one year. Objective: To describe the genotype and characteristics of Mexican patients with infantile-onset PD. Methods: Seven patients with PD confirmed by enzymatic activity determination and GAA gene molecular analysis were included. Mutations were reviewed in genomic databases. Results: Median age at symptom onset was four months (1-12 months) and age at diagnosis was eight months (4-16 months). All patients had cardiomyopathy: four who died before one year of age had mutations that predicted severe disease (c.2431dup, c.2560C>T, c.655G>A, c.1987delC) and were negative for cross-reactive immunologic material (CRIM). Three patients survived after one year of age with enzyme replacement therapy; one survived almost five years, another 18 months, and one girl was almost three years of age at the time of this report; their pathogenic variants predicted potentially less severe disease (c.1979G>A, c.655G>A, c.1447G>A) and they were positive for CRIM. Conclusion: There was a good correlation between genotype and phenotype in children with Pompe disease.