XLAS is caused by pathogenic variants in the COL4A5 gene and according to the character of the X-linked disease, male XLAS cases show much severer phenotypes and develop end-stage renal disease (ESRD) during their 20s and 30s4–6. This evidence concerns the gene COL4A5 and X-linked hydrocephalus with stenosis of the aqueduct of Sylvius.