A Case Refort of Sandhoff Disease

Sandhoff disease is a rare autosomal recessive metabolic disease presenting bilateral optic atrophy and a cherry red spot in the macula. This case report presents the characteristics of a patient with Sandhoff disease as assessed by ophthalmic, neuroimaging, and laboratory procedures. Ophthalmologic examination revealed that the patient could not fixate her eyes on objects nor follow moving targets. A pale optic disc and a cherry red spot in the macula were seen in both eyes. Low signal intensity at the thalamus and high signal intensity at the cerebral white matter were noted in a T2-weighted brain MR image. A lysosomal enzyme assay using fibroblasts showed the marked reduction of both total beta-hexosaminidases, A and B. Based on the above clinical manifestations and laboratory findings, we diagnosed the patient as having Sandhoff disease.

Lysosomal storage disorders.

This study was conducted to assess the variability of clinical expression of Lysosomal storage disorders (LSDs) and the selection of specific enzyme investigation to reach the differential diagnosis. Initially 150 children in the age range of 15 days to 13 years were screened for common metabolic disorder and based on screening results, clinical signs and symptoms, 30 children(4 mo-12 yr) of these were selected for the leukocyte enzyme study. Of these 21 were confirmed to have LSDs. The most common disorder was GM2-gangliosidosis (47.61%, 10/21) followed by mucopolysaccharidosis (33.33%; 7/21). All showed variable phenotypic expression. Metachromatic leukodystrophy (MLD) was observed in 9.5% (2/21) of children with arylsulphatase A enzyme deficiency, while two children had shown pseudodeficiency of arylsulphatase A. One case each of galactosialidosis and GMI-gangliosidosis were observed. We conclude that children with developmental delay, seizures, dysmorphic features and organomegaly, with or without positive urinary screening for common metabolic disorders, need to be investigated further for LSDs.Variability of clinical expression is commonly observed in LSDs which require further confirmation by specific leukocyte enzyme study.

Deficiencia cronica de hexosaminidasa A asociada a neuropatia periferica sensitiva pura / Chronic hexosaminidase A deficiency associated to pure sensory peripheral neuropathy

Se presenta a un paciente con deficiencia de hexosaminidasa A (Hx A), que conduce a la gangliosidosis GM2, que desarrolla un cuadro neurológico progresivo cuyo comienzo pudo fijarse a los 10 años y que se caracterizó por deterioro intelectual, compromiso cerebeloso, alteración de neuromas motoras superior e inferior y neuropatía sensitiva sin aparente compromiso de las fibras motoras que integran el nervio mixto. La biopsia del nervio safeno externo mostró pérdida de fibras mielínicas, en especial de aquellas de mayor y menor diámetro, agrupamiento axonal, axones con cubiertas mielínicas anormalmente finas en relación con su diámetro, degeneración axonal, desmielinización segmentaria y paranodal y remielinización. La microscopia electrónica reveló cuerpos de inclusión electrodensos no específicos e incusiones laminares concéntricas dentro del citoplasma de las células de Schwann. Los hallazgos hechos señalan que la neuropatía sensitiva pura puede formar parte del espectroclínico de la deficiencia de HxA