NOS1 and snowflake vitreoretinal degeneration: Remarkably, six genes represented by differential exon and junction expression in male LVD patients were also represented in female SVD patients, including: F2, a LVD-risk associated gene, nitric oxide synthase (NOS1), paired like homeodomain 2 (PITX2), phospholipid phosphatase 3 (PLPP3), retinoic acid induced 1 (RAI1), and zinc finger C3HC-type containing 1 (ZC3HC1) (Figure 4, Table 7B).