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.

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.