Other pathogenic variants in genes were each found in a single patient, including CDKL5 [16], COL4A1, CPA6, CSNK2A1, DNM1, DYNC1H1, GABRG2, IRF2BPL, KCNQ2, KMT2D, LAMB1, PPT1, PRRT2, SLC2A1, SMARCB1, SYNGAP1, and UNC13D. The latter gene was found to harbor biallelic pathogenic variants in one patient with primary hemophagocytic lymphohistiocytosis who subsequently developed ADEM. Here, COL4A1 is linked to Primary hemophagocytic lymphohistiocytosis.