These six SP variants were in the CRB1 (early-onset retinal dystrophy), NDP (familial exudative vitreoretinopathy) (FEVR), FZD4 (FEVR), EYS (retinitis pigmentosa), and RS1 (X-linked juvenile retinoschisis) genes. This evidence concerns the gene TFF2 and exudative vitreoretinopathy.