For instance, the pattern dystrophy (PD) phenotype associated with the p.Tyr141Cys mutation of PRPH2 (likely secondary to abnormal PRPH2-ROM1 complexes) can be converted to a haploinsufficiency RP phenotype in the complete absence of ROM1 (null alleles) (Conley et al. 2017). Here, PRPH2 is linked to retinitis pigmentosa 1.