Long-read single molecule real-time (SMRT) sequencing of GBA1 locus in Gaucher disease national cohort from Argentina reveals high frequency of complex allele underlying severe skeletal phenotypes: Collaborative study from the Argentine Group for Diagnosis and Treatment of Gaucher Disease.

Gaucher disease is reckoned for extreme phenotypic diversity that does not show consistent genotype/phenotype correlations. In Argentina, a national collaborative group, Grupo Argentino de Diagnóstico y Tratamiento de la Enfermedad de Gaucher, GADTEG, have delineated uniformly severe type 1 Gaucher disease manifestations presenting in childhood with large burden of irreversible skeletal disease. Here using Long-Read Single Molecule Real-Time (SMRT) Sequencing of GBA1 locus, we show that RecNciI allele is highly prevalent and associates with severe skeletal manifestations in childhood.

Genotype-Phenotype Variations of Renal Complications in Fabry Disease Q279X Mutation

Abstract In more than 800 GLA gene mutations causing Fabry Disease (FD), renal involvement vary according to the α-GAL A mutation. The aim is to describe the genotype/phenotype variations of renal complications in two siblings with confirmed FD with the mutation p.Q279X in exon 6. We present a retrospective study of two venezuelan male siblings, ages 34 (patient 1) and 33 (patient 2), evaluated by general lab tests, renal ultrasound, renal scintigram , and renal biopsy. Fabry disease diagnose was made by α-galactosidase A activity determined in dried blood spot. Genomic DNA was sequenced by Sanger method. Patient 1 developed CKD grade 5 and high blood pressure, treated by hemodialysis during 8 years. Patient 2 showed GFR >60 ml/min, and proteinuria less than 600 mg/24H. Renal biopsy showed segmental sclerotic lesions and hypertrophic podocytes with vacuolated cytoplasm. Both patients received ERT every two weeks since 2003. Patient 1 died because dialysis complications (hyperparathyroidism, cardiomyopathy). The genotype/phenotype variation of the c.835C>T mutation (p.Gln279Ter. Q279X) in exon 6 of the GLA gene can express an important renal variation with a wide range of clinical manifestations that cannot be predicted, therefore, an early nephrological evaluation and periodic follow-up of these patients are necessary.

Prevalence of Fabry disease in male dialysis patients: Argentinean screening study.

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by enzyme Alpha-Galactosidase A (α-Gal-A) deficiency, due mutations in GLA gene. Progressive glycolipid accumulation leads to damage in kidney and other organs. The aim of this study was to estimate the prevalence of Fabry disease in Argentinean male patients undergoing dialysis. METHODS: A prospective screening study was carried out measuring the α-Gal-A activity in dried blood spot (DBS) samples of male patients undergoing dialysis from Argentina. Those patients in which DBS α-Gal-A level was low (<4.0 µmol/hr/L), underwent GLA genetic testing for diagnosis confirmation. RESULTS: Nine thousand six hundred and four dialysis male patients from 264 centers distributed over 20 of the 23 provinces of Argentina were investigated. Twenty-four patients showed a decreased or absent α-Gal-A activity in DBS and although genetic analysis found a variant in the GLA gene in every one of these patients, we could confirm FD diagnosis in 22 cases. CONCLUSION: The prevalence rate of FD found in Argentinean male dialysis patients was 0.23%. Classic phenotype was observed in 73% of patients, whereas the remaining 27% presented as late-onset variant. This was the largest study carried out in dialysis patients from a same country at a worldwide level and the first study performed in Argentina.

Enfermedad de Pompe infantil: Diagnóstico y tratamiento / Infantile-onset Pompe disease: Diagnosis and management

La enfermedad de Pompe, o deficiencia de maltasa ácida o glucogenosis tipo II, es una grave enfermedad genética, autosómica recesiva, progresiva, poco frecuente, causada por la deficiencia en la enzima alfa glucosidasa. En la edad pediátrica, puede presentarse con la "forma clásica", la más conocida, con grave compromiso cardíaco y franca hipotonía, o con la "forma no clásica", con comienzo temprano del compromiso motor. La "forma de comienzo tardío" del adulto también puede ocurrir en la infancia o en la adolescencia. Se actualizan los hallazgos clínicos y de diagnóstico disponibles, ya que un tratamiento temprano con reemplazo de la enzima faltante puede mejorar la supervivencia y la calidad de vida del paciente. Se revisan los beneficios y los efectos adversos del tratamiento disponible y nuevas líneas de investigación terapéutica.

Pompe disease, also known as acid maltase deficiency or glycogenosis type II, is a rare severe, autosomal, recessive, and progressive genetic disorder caused by deficiency in alpha-glucosidase. The classic infantile-onset is the most broadly known form of Pompe disease, which presents with severe heart involvement and clear hypotonia, while the non-classic presentation occurs with early motor involvement. Late-onset Pompe disease develops in adults, but it may also occur during childhood or adolescence. Here we update the available clinical and diagnostic findings because an early management with enzyme replacement therapy may improve patients' survival and quality of life. We also review the benefits and adverse effects of available treatments and new lines of therapeutic research.

Infantile-onset Pompe disease: Diagnosis and management. / Enfermedad de Pompe infantil: Diagnóstico y tratamiento.

Pompe disease, also known as acid maltase deficiency or glycogenosis type II, is a rare severe, autosomal, recessive, and progressive genetic disorder caused by deficiency in alpha-glucosidase. The classic infantile-onset is the most broadly known form of Pompe disease, which presents with severe heart involvement and clear hypotonia, while the non-classic presentation occurs with early motor involvement. Late-onset Pompe disease develops in adults, but it may also occur during childhood or adolescence. Here we update the available clinical and diagnostic findings because an early management with enzyme replacement therapy may improve patients' survival and quality of life. We also review the benefits and adverse effects of available treatments and new lines of therapeutic research.

La enfermedad de Pompe, o deficiencia de maltasa ácida o glucogenosis tipo II, es una grave enfermedad genética, autosómica recesiva, progresiva, poco frecuente, causada por la deficiencia en la enzima alfa glucosidasa. En la edad pediátrica, puede presentarse con la "forma clásica", la más conocida, con grave compromiso cardíaco y franca hipotonía, o con la "forma no clásica", con comienzo temprano del compromiso motor. La "forma de comienzo tardío" del adulto también puede ocurrir en la infancia o en la adolescencia. Se actualizan los hallazgos clínicos y de diagnóstico disponibles, ya que un tratamiento temprano con reemplazo de la enzima faltante puede mejorar la supervivencia y la calidad de vida del paciente. Se revisan los beneficios y los efectos adversos del tratamiento disponible y nuevas líneas de investigación terapéutica.

Clinical parameters, LysoGb3, podocyturia, and kidney biopsy in children with Fabry disease: is a correlation possible?

BACKGROUND: Fabry disease is an X-linked lysosomal storage disorder caused by α-galactosidase enzyme deficiency. We present clinical, biochemical, and histologic findings in children with classical phenotypic presentation of Fabry disease. METHODS: A retrospective analysis was performed using charts from 14 children with confirmed diagnosis. Clinical parameters were evaluated. Globotriaosylsphingosine -lysoGb3- detection in plasma, podocyturia, and kidney biopsy were carried out in all cases. RESULTS: All patients except one demonstrated at least one symptom of Fabry disease. LysoGb3 levels were above the normal range in all patients. Podocyturia was documented in all patients. Kidney biopsy revealed glomerular, interstitial, vascular, and tubular changes on light microscopy in nearly all patients. Electron microscopy showed podocyte inclusions in all patients. CONCLUSIONS: No difference in symptomatology was discernible between boys and girls. Podocyturia was detectable in children serving as a possible early marker of kidney injury. LysoGb3 was elevated in all cases, emphasizing the importance for diagnosis especially in female patients with normal αGal A activity. A possible association between lysoGb3 and symptom severity and histological involvement in kidney biopsy should be assessed in prospective studies with enough statistical power to determine if lysoGb3 can be used to predict nephropathy in children with Fabry disease.