Report of a Case that Expands the Phenotype of Infantile Krabbe Disease.

BACKGROUND Krabbe disease, or globoid cell leukodystrophy, is an autosomal recessive disease caused by the deficiency of lysosomal galactocerebrosidase. The most common form is infantile Krabbe disease, which is usually diagnosed within the first year of life and has high morbidity and mortality. Patients usually present with irritability, progressive neurodegeneration, spasticity, and peripheral neuropathy. This report is of a 6-year-old girl who had Krabbe disease since she was 5 weeks of age. CASE REPORT A 6-year-old female Saudi patient had initially presented at 5 weeks of age with hypoventilation, recurrent attacks of fever, and failure to thrive. The patient also skin hypopigmentation involving the face, neck, upper extremities, and lower extremities. Peripheral blood galactocerebrosidase enzyme activity was normal but was reduced in tissue fibroblasts. Whole exome sequencing (WES) and whole genome sequencing (WGS) showed a homozygous mutation in the GALC gene c.334A>G (p.Thr112Ala), which was previously reported in a compound heterozygous state with another mutation. CONCLUSIONS This case report describes a patient with homozygous mutation status Krabbe disease. Although this patient had the phenotype of early infantile-onset Krabbe disease, which usually has high morbidity and mortality, her condition is now relatively stable at 6 years of age, which could be due to relatively higher enzyme activity. This case also expanded the presentation or typical phenotype of infantile Krabbe disease as the patient also presented with hypoventilation and skin hypopigmentation.