Altogether 20 mutations have been described in the MERTK gene causing RP, the majority being missense/nonsense mutations (11), splicing-site mutations (3), small deletions (3), insertions (1) and gross deletions (2) as reported in the HGMD public database (last accessed January 8, 2015). The gene discussed is MERTK; the disease is retinitis pigmentosa 1.