Generation of cDNA-expressing vectors of normal and rs10314 variant claudin-5 genes showed the rs10314 variant gene expresses 50% less claudin-5 protein in cells (Figure 1d), suggesting that individuals with 22q11DS carrying the rs10314 variant may express up to 75% less claudin-5 at their BBB than the general population (50% for 22q11DS with the wild-type variant due to haploinsufficiency and down by 75% for 22q11DS with the rs10314 variant on top of haploinsufficiency). Here, CLDN5 is linked to 22q11.2 deletion syndrome.