Abstract
BACKGROUND: Krabbe disease (KD; globoid cell leucodystrophy) is a rare autosomal recessive lipid storage disorder that affects the white matter of the peripheral and central nervous. Late-onset KD is less frequently diagnosed and often presents with milder symptoms, making accurate diagnosis challenging, especially when distinguishing it from peripheral neuropathy. In this report, we present two cases of late-onset KD in a Chinese family. The first case involves a 25-year-old female who sought treatment due to long-standing spastic gait and deformities in her lower limbs. A muscle biopsy revealed muscle atrophy, and electromyography indicated neurogenic damage. Her 27-year-old sister (Case 2) exhibited similar lower limb weakness, along with more severe central and peripheral neurological symptoms. METHODS: The patients' peripheral blood was retained for galactocerebrosidase (GALC) enzyme activity assaying and whole exome gene sequencing. RESULTS: GALC enzyme activity assaying showed decreased GALC activity and gene sequencing revealed homozygous mutation of p.L634S (c.1901T>C) in the two cases. CONCLUSION: This study broadens the scope for considering of KD in the diagnosis of patients presenting with muscle weakness and deformities in the lower limbs.