A 2-year-old male presents with progressive neurological deterioration, developmental regression, and cherry-red macular spots on ophthalmologic examination. Vital signs show HR 98/min, RR 22/min, BP 95/62 mmHg, and temperature 37.2°C. Serum hexosaminidase A levels are markedly decreased at 2 U/L (normal: 8-15 U/L), while hexosaminidase B remains normal. The patient denies recent fever. This biochemical defect would most appropriately be categorized as belonging to which of the following general classes of metabolic disorders?

1. A)Mucopolysaccharidosis
2. B)Lipid metabolism
3. C)GangliosidosisGABARITO
4. D)Aminoacidopathy
5. E)Porphyria