Author information: (1)Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA. (2)Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA. (3)Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA. (4)Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA. (5)Division of Medical Genetics, Department of Pediatrics, Duke University School of Medicine, Durham, NC 27710, USA. (6)Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. (7)Med Biotech Hub and Competence Center, Department of Medical Biotechnologies, University of Siena, Siena 53100, Italy. (8)Medical Genetics, University of Siena, Siena 53100, Italy. (9)Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena 53100, Italy. (10)Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA. (11)Division of Neuroradiology, Department of Radiology, Duke Health, Durham, NC 27710, USA. (12)Division of Pediatric Neurology, Department of Pediatrics, Duke Health, Durham, NC 27710, USA. (13)Department of Ophthalmology, Duke Health, Durham, NC 27710, USA. (14)Department of Medical Genetics, NeuroImaging and NeuroInterventional Unit, Azienda Ospedaliera e Universitaria, Senese, Siena 53100, Italy. (15)Yale School of Medicine, New Haven, CT 06510, USA. (16)Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.