ULTRASTRUCTURAL PATHOLOGY OF SKIN BIOPSY AND FIBROBLAST ENZYME STUDIES IN A CASE OF GM₂-GANGLIOSIDOSIS WITH DEFICIENT HEXOSAMINIDASE A AND THERMOLABILE HEXOSAMINIDASE B

Abstract

A 2 year-old non-Jewish boy had muscle hypertonia, a black cherry spot, dementia, and seizures. His skin biopsy showed membranous cytoplasmic bodies in axonal terminals and zebra body-like inclusions in Schwann cells. Biochemically, a deficiency of Hex A and two separate Hex B peaks indicated a type 1 (B variant, Tay Sachs) like subvariant of GM2-gangliosidosis.

Infantile cardiomyopathy and neuromyopathy with ?-galactosidase deficiency

“…These membrane bound vacuoles represent lysosomal residual bodies storing a keratan sulfate-like mucopolysaccharide [21]. In GM1- [4] and GM2- [3] gangliosidoses, intradermal axons have also been shown to harbour osmiophilic dense bodies. This intra axonal accumulation of organelles may represent a locally invoked phenomenon or a reaction to lysosomal crowding in the respective neuronal perikarya.…”

B1 Variant of GM2 Gangliosidosis in a 12-Year-Old Patient1

“…The unmyelinated and myelinated axons were enlarged by numerous dense bodies and some membranous inclusions, among them several of the MCB type. In this respect, the diagnostic procedures to clarify our patient's disorder resembled that followed in a previous similar patient (12). Nonspecific enlargement ofaxons, particularly of their terminal segments, is not confined to the GMt or G M 2 gangliosidoses, but is seen rather in a broad variety of lysosomal disorders.…”

“…In GM2 gangliosidosis, it has previously (11) been shown that studying axons, particularly axonal terminals, in biopsied skin specimens may be particularly rewarding in that axonal enlargement due to accumulation of mitochondria, dense bodies, and not infrequently of rather disease-specific lysosomal residual bodies may be present. This approach has previously resulted in the demonstration of a B subvariant of GM2 gangliosidosis in a young Turkish child (12). In this article we report a 12-y-old patient with the B 1 variant of GM2 gangliosidosis.…”