The disease severity was variable between families, with 5 affected individuals in family II dying in early infancy (the homozygous YIPF5 mutation could be confirmed only in the proband, as DNA was not available from siblings), while patient I is reported to have normal neuromotor development at the age of 5 years and his epilepsy resolved at the age of 2 years. This evidence concerns the gene YIPF5 and epilepsy.