{Reference Type}: Review {Title}: DEGS1 -related leukodystrophy: a clinical report and review of literature. {Author}: Wong MST;Thomas T;Lim JY;Kam S;Teo JX;Ching J;Goh CYJ;Jamuar SS;Lim WK;Koh AL; {Journal}: Clin Dysmorphol {Volume}: 32 {Issue}: 3 {Year}: 2023 Jul 1 {Factor}: 0.884 {DOI}: 10.1097/MCD.0000000000000457 {Abstract}: BACKGROUND: Leukodystrophies are a heterogeneous group of disorders affecting the white matter of the central nervous system, with or without affecting the peripheral nervous system. Biallelic variants in DEGS1 , coding for desaturase 1 (Des1) protein, were recently reported to be associated with hypomyelinating leukodystrophy (HLD), a subclass of leukodystrophies where the formation of the myelin sheath is affected.
METHODS: Genomic sequencing was performed on our index patient with severe developmental delay, severe failure to thrive, dystonia, seizures, and hypomyelination on brain imaging. Sphingolipid analysis was performed and dihydroceramide/ceramide (dhCer/Cer) ratios were obtained by the measurement of ceramide and dihydroceramide species.
RESULTS: A homozygous missense variant was identified in DEGS1 (c.565A > G:p Asn189Asp). The identified DEGS1 variant has been annotated as "conflicting reports of pathogenicity" on ClinVar. Follow-up sphingolipid analysis on our patient showed significantly raised dhCer/Cer and this was consistent with dysfunction of the Des1 protein, providing additional evidence to support the pathogenicity of this variant.
CONCLUSIONS: While rare, pathogenic variants in DEGS1 should be considered in patients with HLD phenotype. To date, 25 patients have been reported across four studies on DEGS1 -related HLD, and, in this report, we summarize the literature. More such reports will enable deeper phenotypic characterization of this disorder.