We thank Chad Pearson and Mary Pinter for POC1B antibodies, Carsten Janke for the polyglutamylated tubulin antibody, Camiel Boon for ascertainment of affected persons, and Saskia van der Velde-Visser and Alejandro Garanto for expert technical assistance. This study was financially supported by the Foundation Fighting Blindness (grants BR-GE-0510-04890RAD to A.I.d.H., C-CMM-0811-0547-RAD03 to H.K. and E.v.W., C-CMM-0811-0546-RAD02 to R.R., and C-GE-0811-0545-RAD01 to F.P.M.C., A.I.d.H., and R.W.J. Collin); the Algemene Nederlandse Vereniging ter Voorkoming van Blindheid; the Gelderse Blinden Stichting; the Landelijke Stichting voor Blinden en Slechtzienden; the Stichting Blinden-Penning; the Stichting Macula Degeneratie fonds; the Rotterdamse Stichting Blindenbelangen (F.P.M.C. and C.C.W.K.); the Netherlands Organisation for Scientific Research (grants Vici-016.130.664 to R.R., Veni-91613008 to H.H.A., and Veni-016.136.091 to E.v.W.); the Netherlands Organisation for Health Research and Development (ZonMW E-rare grant 40-42900-98-1006 to E.v.W.); the European Community’s Seventh Framework Programme FP7/2009 (grant agreement 241955 SYSCILIA to H.K. and R.R.); and an institutional Ph.D. grant from Radboudumc to H.H.A.