A new compound heterozygous mutation in adult-onset Krabbe disease

Abstract

Purpose: Krabbe disease (KD) or globoid cell leukodystrophy is an autosomal recessive lysosomal disorder caused by a lack of the lysosomal enzyme galactocerebrosidase (GALC) because of mutations in GALC. Patients with KD exhibit a wide spectrum of clinical symptoms; therefore, their diagnosis can be challenging. We report the clinical features and gene mutations in a 48-year-oldpatient with adult-onset KD.

Methods: We collected and analyzed clinical data of the patientwith a diagnosis of KD. Gene mutations were identified by whole exome sequencing.

Results: We describe a case of adult-onset KD caused by a novel compound heterozygous mutation; a missense mutation, c. 1901 T > C (p. L634S); and a novel nonsense mutation, c.1005C > G (p. Y335X), in GALC. The disease onset started when the patient was 40 years old, and manifested as typical paralytic paraplegia. Magnetic resonance imaging indicated demyelination of the white matter, which is consistent with the typical symptoms of adult-onset KD. Biochemical analysis revealed GALC activity to be 1.5 nmol/17 h/mg protein, confirming its deficiency and KD diagnosis.

Conclusions: Our findings provide evidence of a novel mutation, providing additional information toward to the GALC mutation database.

Keywords:

• Krabbe disease
• GALC gene
• Galactocerebrosidase
• Globoid cell leukodystrophy

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

This study was supported by grants from National Natural Science Foundation of China (No.81971214, 81701272), Provincial Ministry Co-construction Project from Medical Scientific and Technological Research Program of Henan Province (SB201902011) and Training plan for young backbone teachers of Zhengzhou University (2019ZDGGJS056).