Clinical and genetic characteristics of 2 cases with infantile GM1 gangliosidosis / 中华实用儿科临床杂志

Objective:To analyze clinical and genetic characteristics of 2 cases with infantile GM1 gang-liosidosis.Methods:Clinical data of 2 cases with infantile GM1 gangliosidosis in the Department of Rehabilitation, Tianjin Children′s Hospital from May 2019 to June 2019 were retrospectively analyzed.Results:The major manifestations of 2 cases included infantile onset, psychomotor retardation and retrogression, blundering face, sensitive to sound, gingival hyperplasia, abnormal eruption of teeth, hypotonia or dystonia, bone dysplasia, and skin abnormalities.Case 1 had hepatosplenomegaly, corneal opacity and multiple joint contractures.Case 2 had fundus cherry erythema and epileptic seizure.Biochemical results showed that alkaline phosphatase and aspartate transaminase significantly increased, and alanine transaminase was normal.Cranial nuclear magnetic imaging showed poor myelin sheath in the white matter in both cases, and case 1 also had symmetric signal changes in the thalamus.Whole exon sequencing showed that case 1 had deletion mutation of 3p22.3 (33137821-33138587)×1 in the exon of GLB1 gene, which has not been previously reported. Conclusions:The clinical spectrum of infantile GM1 gangliosidosis is broad.Both cases in this study have skin abnormalities, which are relatively rare.Multiple joint contractures in case 1 have not been previously reported, and considered as a new phenotype.The deletion mutation of 3p22.3 (33137821-33138587)×1 in the exon of GLB1 gene in case 1 is a newly detected mutation, which expands the genetic profile of infantile GM1 gangliosidosis.

GM1 gangliosidosis: a case report / Gangliosidose GM1: um relato de caso

RESUMEN La gangliosidosis GM1 es un trastorno lisosomal caracterizada por la acumulación de gangliósido GM1 (glucoesfingolípido) en el sistema nervioso central (SNC) y visceral, debido a la deficiencia de la enzima beta-galactosidase (hidrolasa lisosomal). Afecta principalmente al SNC y las vísceras y produce importantes anomalías esqueléticas, que a menudo ocurren con la presencia de linfocitos vacuolados en la muestra de la sangre periférica o médula ósea. Tiene tres formas de presentación, lo que dificulta aún más su identificación debido al amplio espectro clínico. El presente estudio tiene como objetivo describir un caso de gangliosidosis GM1 en un paciente masculino, nacido a las 38 semanas. Hasta el momento, no existe un tratamiento efectivo para la gangliosidosis GM1, es decir, el portador de la enfermedad solo recibe medidas sintomáticas y paliativas. Por tanto, el diagnóstico precoz de la enfermedad es de suma importancia, ya que su única forma de prevención, actualmente, es a través del consejo genético.

β-Galactosidase Deficiency in Colombia: Report of 20 Patients Detected Using Dried Blood Spot Samples

Abstract β-Galactosidase (BGal) is the first enzyme involved in the catabolism of sphingolipids. Two pathologies have been directly associated with its deficiency: GM1 gangliosidosis and Morquio B. Morquio B is among the rarest types of mucopolysaccharidosis (MPS). We aim to document the β-galactosidase deficiency in Colombia. We evaluated leukocytes from 1492 healthy Colombian individuals and 923 patients, referred between 2005 and August 2014. Dried blood spot (DBS) samples from the same number of patients were evaluated. β-Galactosidase was measured with 4-methylumbelliferyl-β-d-galactoside. As a control enzyme, the total hexosaminidase activity was also evaluated. We identified 14 patients with GM1 gangliosidosis, 5 patients with Morquio B, and 1 patient with I-cell disease. We could establish a reference value for Bgal in Colombian leukocyte samples. GM1 gangliosidosis is the main pathology associated with a direct deficiency of BGal. The high number of patients found with MPS IVB indicates that there are patients who could be misdiagnosed due to an unawareness of the disease.

Gangliosidosis generalizada tipo 1 / Generalized gangliosidosis type 1

La gangliosidosis generalizada tipo 1 es una enfermedad de acúmulo lisosomal producida por mutaciones en el gen de la enzima b-galactosidasa, caracterizada fundamentalmente por toma del sistema nervioso central, la visceromegalia, disostosis ósea y dimorfismo facial. Se presenta el caso de un lactante varón, hijo de padres no consanguíneos, de 5 meses de edad, Apgar 6/8 debido a hipoxia neonatal, con historia de múltiples ingresos por enfermedad diarreica e infecciones respiratorias. Es remitido a la Consulta de Genética Clínica por retardo del desarrollo psicomotor, macrocráneo y hepatomegalia, además de máculas hipercrómicas en piel. En el examen físico se encontraron evidencias de una posible afectación por enfermedad metabólica lisosomal. Entre las enfermedades a descartar estaban la galactosialidosis, de características clínicas similares, y la enfermedad de Morquio, con diferente presentación clínica pero idéntico defecto enzimático

Generalized or GM 1 gangliosidosis is a lysosomal storage disease caused by mutations in the enzyme b-galactosidase gene, mainly characterized by affecting the central nervous system, visceromegalia, osseous dysostosis and facial dimorphism. This is the case of a male nursling born to non-consanguineous parents, 5 months of age, Apgar index of 6/8 due to neonatal hypoxia, with a history of several admissions to hospital because of diarrheal disease and respiratory infections. He was referred to the clinical genetic service since he presented with retarded psychomotor development, macrocrania and hepatomegalia, in addition to hyperchromic skin spots. The physical exam found evidence of possible effects by lysosomal metabolic disease. Among the diseases to be ruled out for the diagnosis were galactosialidosis of similar clinical characteristics and Morquio B disease with different clinical presentation but identical enzymatic deficiency

Population analysis of the GLB1 gene in South Brazil

Infantile GM1 gangliosidosis is caused by the absence or reduction of lysosomal beta-galactosidase activity. Studies conducted in Brazil have indicated that it is one of the most frequent lysosomal storage disorders in the southern part of the country. To assess the incidence of this disorder, 390 blood donors were tested for the presence of two common mutations (1622-1627insG and R59H) in the GLB1 gene. Another group, consisting of 26 GM1 patients, and the blood donors were tested for the presence of two polymorphisms (R521C and S532G), in an attempt to elucidate whether there is a founder effect. The frequencies of the R59H and 1622-1627insG mutations among the GM1 patients studied were 19.2 percent and 38.5 percent, respectively. The frequency of polymorphism S532G was 16.7 percent, whereas R521C was not found in the patients. The overall frequency of either R59H or 1622-1627insG was 57.7 percent of the disease-causing alleles. This epidemiological study suggested a carrier frequency of 1:58. Seven different haplotypes were found. The 1622-1627insG mutation was not found to be linked to any polymorphism, whereas linkage disequilibrium was found for haplotype 2 (R59H, S532G) (p < 0.001). These data confirm the high incidence of GM1 gangliosidosis and the high frequency of two common mutations in southern Brazil.

Transient high-level expression of ß-galactosidase after transfection of fibroblasts from GM1 gangliosidosis patients with plasmid DNA

GM1 gangliosidosis is an autosomal recessive disorder caused by the deficiency of lysosomal acid hydrolase ß-galactosidase (ß-Gal). It is one of the most frequent lysosomal storage disorders in Brazil, with an estimated frequency of 1:17,000. The enzyme is secreted and can be captured by deficient cells and targeted to the lysosomes. There is no effective treatment for GM1 gangliosidosis. To determine the efficiency of an expression vector for correcting the genetic defect of GM1 gangliosidosis, we tested transfer of the ß-Gal gene (Glb1) to fibroblasts in culture using liposomes. ß-Gal cDNA was cloned into the expression vectors pSCTOP and pREP9. Transfection was performed using 4 µL lipofectamine 2000 and 1.5-2.0 µg DNA. Cells (2 x 10(5)/well) were harvested 24 h, 48 h, and 7 days after transfection. Enzyme specific activity was measured in cell lysate and supernatant by fluorometric assay. Twenty-four hours after transfection, treated cells showed a higher enzyme specific activity (pREP9-ß-Gal: 621.5 ± 323.0, pSCTOP-ß-Gal: 714.5 ± 349.5, pREP9-ß-Gal + pSCTOP-ß-Gal: 1859.0 ± 182.4, and pREP9-ß-Gal + pTRACER: 979.5 ± 254.9 nmol·h-1·mg-1 protein) compared to untreated cells (18.0 ± 3.1 for cell and 32.2 ± 22.2 nmol·h-1·mg-1 protein for supernatant). However, cells maintained in culture for 7 days showed values similar to those of untreated patients. In the present study, we were able to transfect primary patients' skin fibroblasts in culture using a non-viral vector which overexpresses the ß-Gal gene for 24 h. This is the first attempt to correct fibroblasts from patients with GM1 gangliosidosis by gene therapy using a non-viral vector.

A Galactosialidosis Mimicking GM1-gangliosidosis Type I

Galactosialidosis is a lysosomal storage disease associated with a combined deficiency of beta-galactosidase and alpha-neuraminidase, secondary to a defect of another lysosomal protective protein. It is a neurodegenerative disorder clinically characterized by psychomotor deterioration, cerebellar ataxia, coarse facies, generalized bony deformity and organomegaly. Three phenotypic subtype are recognized:early infantile, late infantile and juvenile/adult type. We report a 13 months old boy with a late infantile galactosialidosis. He was presented with progressive mental regression and motor disturbance and observed cherry red spot, hearing loss, moderate dysostosis multiplex and vacuolated lymphocytes in peripheral blood. He showed only beta-galactosidase deficiency in the lymphocytes and was diagnosed as GM1-gangliosidosis type 1. However, further studies revealed the possible defect of alpha-neuraminidase suggesting that he was a case of galactosialidosis which was mimicking GM1-gangliosidosis type 1.

Sphingolipidoses / 한양의대학술지

Sphingolipidoses are a subgroup of lysosomal storage disorders. They are characterized by relentless progressive storage in affected organs and concomitant functional impairments. No overall screening procedure for these disorders is available. Their course and appearance, however, are usually characteristic and, together with relevant technical procedures such as magnetic resonance imaging (MRI), clinical neurophysiology, ophthalmologic examination, etc., a provisional diagnosis can be made, after which enzymatic diagnosis can close the gap in the diagnostic process. Subgroups of sphingolipidoses are grouped together, such as disorders with prominent hepatosplenomegaly (Niemann-Pick A, B and Gaucher disease) and disorders with central and peripheral demyelination (metachromic leukodystrophy and Krabbe disease). Farber disease and Fabry disease are unique in themselves. The last decade has seen hopeful progress in therapeutic strategies, especially for Gaucher disease. Therefore, emphasis of this review has been placed on these new developments.