Late-infantile GM1 gangliosidosis: A case report

Abstract

Rationale: Monosialotetrahexosylganglioside (GM1) gangliosidosis is a rare lysosomal storage disorder caused by the deficiency of ß-galactosidase. Because clinical symptoms of GM1 gangliosidosis overlap with other neurodevelopmental disorders, the diagnosis of this disease is not easy, specifically in late infantile GM1 gangliosidosis. This report described a case of late-infantile GM1 gangliosidosis mistaken for juvenile idiopathic arthritis.

Patient concerns: A 16-year-old girl was referred to our hospital due to persistent multiple joint deformities and mental retardation, which could not be explained by juvenile idiopathic arthritis.

Diagnosis: We made a diagnosis of late infantile GM1 gangliosidosis through enzyme assays and genetic testing after a skeletal survey.

Interventions: The patient underwent cervical domeplasty and laminectomy for cord compression and received rehabilitation treatment.

Outcomes: The patient is receiving multidisciplinary care at a tertiary center for variable skeletal disease and conditions associated with GM1 gangliosidosis.

Lessons: Late infantile GM1 gangliosidosis should be considered in the differential diagnosis of progressive neurologic decline and skeletal dysostosis.

Figure 1

Knee and pelvic radiographs (A, B: patient's age:11 years old) and Right upper extremities, hands, spine lateral radiographs (C, D, E: patient's age: 23 years old). (A and B) Diffuse bony irregularity in articular surface of both knee. Flattened femoral head and articular surface, mild subluxation on the left superior femoral head. Secondary osteoarthritic change at both hip and knee joints. (C) Right upper extremity X-ray showed bowing deformities of both humerus, radius, and ulna. Both humeral heads showed deformity due to epiphyseal dysplasia. (D) Carpal bones and the distal epiphysis of both radius and ulna showed deformity. (E) Spine lateral X-ray showed congenital vertebral block in C3–C5.

Figure 2

The proband had compound heterozygote mutations, c.574T>C (p.Tyr192His) and c.601C>T (p.Arg201Cys) in GLB1. Both parents were heterozygous carriers.

Figure 3

Spine MRI (A: patient's age: 26 years old) and brain MRI (B, C: patient's age: 23 years old) in the patient with the late-infantile form of GM1 gangliosidosis. (A) T2 sagittal image showed compressive myelopathy at the level of C2–C3 and C3–C5 (arrows). Congenital vertebral block at the level of C3–C5 and T–T2 (arrow heads) were noted. (B) T2 axial image showed prominent ventricles and CSF space. (C) T2 axial image showed diffuse atrophy of the cerebral and cerebellar hemispheres.