Retinitis pigmentosa (RP) is a genetically inherited eye disease, and is the most frequent cause of inherited blindness worldwide. More than 80 genes have been identified in which defects can cause RP, although in approximately 20-40% of the patients still no genetic explanation can be found. In this study, we have associated genetic defects in the KIAA1549 gene in patients from two unrelated families with RP. Although a function of KIAA1549 in the eye was unknown, our results show that this protein is present in a specific part of the light-sensing cells (photoreceptors) of the mouse retina. This indicates KIAA1549 could have an essential function required for vision. (By Ms. Susanne Roosing, https://jmg.bmj.com/content/early/2018/08/17/jmedgenet-2018-105364 )