Retarded bone formation in GM1-gangliosidosis: a study of the infantile form and comparison with two canine models.

The development of skeletal lesions in two canine models of GM1-gangliosidosis, English springer spaniels and Portuguese water dogs, has been studied and compared to osseous abnormalities in a child with the infantile form of the disease. In the canine models, skeletal dysplasia was progressive. Lesions were noted at 2 months of age and characterized by retarded endochondral ossification and osteoporosis. Older puppies had focal cartilage necrosis within lumbar vertebral epiphyses. At the cellular level, lesions were characterized by chondrocytic hypertrohy and lysosomal accumulation of storage compounds. Our studies illustrate that the skeletal lesions in both canine models are similar to those in a child with GM1-gangliosidosis. Furthermore, we proposed that the abnormal storage of partially degraded compounds in affected chondrocytes might explain, at least in part, the retarded bone formation noted in patients with GM1-gangliosidosis.