Résumé
Objective:To investigate the clinical and genetic characteristics of patients with late-onset subtypes (adolescent or adult) of Krabbe disease.Methods:The clinical data of 7 patients with Krabbe disease admitted to Shanghai Jiao Tong University Affiliated Sixth People′s Hospital and Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from September 2006 to June 2021 were analyzed and Sanger sequencing of the galactosylceramidase (GALC) gene (NM_000153) and detection of the activity of GALC were conducted. A total of 61 cases of Krabbe disease reported in domestic literature were reviewed and summarized.Results:Among the 7 patients with Krabbe disease, there were 4 males and 3 females. All of them had lower limb weakness or walking difficulty as the initial symptoms, and presented as spastic paraplegia. The symptoms were relatively mild in patients with late onset. There were 4 out of 5 patients undergoing magnetic resonance imaging examination, who showed abnormal signals: 2 had brain atrophy and the remaining 2 had white matter lesions. A total of 5 GALC gene mutations were detected by genetic analysis. Among these, c.1901T>C (p.L634S), c.908C>T(p.S303F) and c.461C>A(p.P154H) are known variants, while c.50_51insTT (p.M17Ifs) and c.1130delT(p.L337X) are novel variants reported for the first time in this paper.Conclusions:Krabbe disease is a rare neurodegenerative disease with phenotypic heterogeneity, which is inherited in an autosomal recessive mode. The severity of clinical manifestations of Krabbe disease is correlated with the age of onset.
Résumé
Objective To explore the clinical, radiological features and gene mutation of GALC gene in one child with globoid cell leukodystrophy (Krabbe disease). Methods The clinical and radiological data of a patient diagnosed with Krabbe disease through next-generation sequencing were retrospectively analyzed. Sanger sequencing was used to confirm the results. Results The patient was late infantile form with main manifestations of progressive psychomotor regression and convulsion. Brain MRI showed symmetric long T1 and long T2 signal changes in the white matter next to lateral ventricle angle, posterior limb of internal capsule, and the ministry of corpus callosum. The patient was found to have compound heterozygous mutations of c.1832T>C in exon 15 and c.979T>G in exon 9, which resulted in amino acid changes of p.L611S and p.F327V, respectively. Sanger sequencing results showed that the two heterozygous mutations were correspondingly inherited from his mother and father. Conclusions Next-generation sequencing technology is a useful tool for the detection of GALC gene mutation, which is valuable for definite diagnosis and differential diagnosis of Krabbe disease in clinical practice.
Résumé
Objective To investigate the clinical, biochemical and genetic features of a Chinese boy with early-onset glo-boid cell leukodystrophy (GLD). Methods The clinical and genetic data of a rare case of early-onset GLD were retrospectively analysed. Results At 2 months after birth, the boy showed progressive psychomotor regression. At 4 months of age when the boy was taken to a doctor, the pyramidal sign was positive. The cranial MRI showed that the body of the lateral cerebral ventri-cles was slightly enlarged and the brain ditch crack of frontal-temporal-parietal lobe was widened and deepened. On his brain CT scan, high signals in bilateral basal ganglia, thalami, cerebellar hemisphere were observed.β-galactosylceramidase (GALC) ac-tivity in the peripheral leucocytes was signiifcantly decreased (3.9 nmol/g protein.h). On his GALC gene, one homozygous novel mutation c.868C>T on exon 8 was found, which resulted in the amino acid change on p.R290C proteins. Conclutions Early-on-set GLD is a rare autosomal-recessive hereditary lysosomal storage disease with a terrible prognosis, in which beta-galactose glu-coside enzyme deifciency is induced by GALC gene mutation. The diagnosis of early-onset GLD is dififcult and should depend on enzyme assay and gene testing.