One patient (Pt6) presented with compound heterozygous variants c.203A>T (p.Lys68Met) and c.395C>A (p.Thr132Asn) in GLIALCAM, while the five remaining patients (Pt1–Pt5) harbored only one variant in GLIALCAM. Of the five patients with mono-allelic variant in GLIALCAM, four patients (Pt1–Pt3, and Pt5) shared the same variant c.274C>T(p.Arg92Trp), which has been reported in patients with MLC before [4], while Pt4 had a novel variant c.275G>C(p.Arg92Pro) (Fig. S3), which has not been reported before. This evidence concerns the gene HEPACAM and megalencephalic leukoencephalopathy with subcortical cysts.