Generation of a human induced pluripotent stem cell line, PKUHSCi001-A, from a patient with infantile epileptic spasms syndrome carrying a de novo PHF21A variant.

Infantile epileptic spasms syndrome (IESS) is a severe, early-onset epileptic encephalopathy in which PHF21A has recently emerged as a candidate disease gene, and until now no patient-derived cell model carrying a PHF21A variant has existed. We derived an induced pluripotent stem cell (iPSC) line, PKUHSCi001-A, from blood mononuclear cells of an 11-month-old boy with IESS who carries a de novo heterozygous PHF21A variant (c.1112_1113insGTC, p.Ser371_Leu372insSer). The line retains this variant, shows normal morphology and karyotype, expresses markers of undifferentiated hPSC state, and differentiates into all three germ layers, offering a new tool for studying PHF21A/BHC80 function and PHF21A-related epileptic encephalopathy.