Bernd Wissinger graduated in biology and is currently full professor for Molecular Genetics of Sensory Systems at the University Tübingen and Head of the Molecular Genetics Laboratory at the Institute for Ophthalmic Research. His main research interests focus on the genetic basis of inherited retinal dystrophies, color vision deficiencies and optic neuropathies, the functional analyses of mutant gene products (among others CNGA3, PDE6C), the generation of homologous animal models (mouse and zebrafish) and quantitative genetics of gene expression (eQTLs). Dr. Wissinger has co-authored more than 170 peer-reviewed papers including publications in Science, Cell, Nature Genetics, PNAS, etc. He serves as ad hoc reviewer for >45 scientific journals and numerous funding agencies. He has been scientific coordinator of several research consortia including a State’s priority research project on Color Vision deficiencies, a DFG-funded Clinical Research Group (2005 – 2011) and a National Rare Disease Network (2009-2015), both on Inherited Retinal Dystrophies, and currently coordinates a project on gene augmentation therapy for CNGA3-linked achromatopsia. Dr. Wissinger served as deputy chief for the ‘Genetics’ section within the German Ophthalmological Society (DOG) from 2011-2016 and is an active members of the scientific advisory board for the Achromatopsia e.V. and the BCM Family Foundation patient organizations.

Abstract: Genetics of Inherited Colorblindness in Humans

Inherited Colorblindness in Humans comprises selective dysfunction of defects of the short wavelength-sensitive (SWS), the MWS or the LWS cone or the simultaneous absence of MWS and LWS cone function (termed Blue Cone Monochromacy [BCM]) or all three subtypes of human cone photoreceptors (termed Rod Monochromacy or Achromatopsia [ACHM]). ACHM is a rare, autosomal recessive inherited disorder that features total colorblindness low vision, photophobia and nystagmus. ACHM is genetically heterogeneous and is caused by mutations in genes encoding essential components of the cone phototransduction cascade (cGMP-gated channel, transducin, phosphodiesterase). Surprisingly we recently discovered that also mutations in ATF6, encoding an ER-resident protein stress sensor that participates in the Unfolded Protein Response (UPR), can cause ACHM. On the hand, BCM and selective forms of color blindness are genetically more unique and linked to mutations in the genes encoding for the apo-protein of the respective photopigment (cone opsins). Separate genes for LWS and MWS opsins in Old World Primates are a result of a recent local gene duplication on the X-chromosome. The high sequence identity of LWS and MWS opsin genes induces unequal homologous recombination during meiosis that causes changes in copy numbers and the formation of diverse LWS/MWS or MWS/LWS hybrid genes underlying most common selective color vision defects. Subjects with BCM have lost both LWS and MWS opsin function either due to larger deletions including regulatory sequence elements or the presence of loss-of-function mutations in all expressed LWS/MWS opsin gene copies. In this talk I will briefly review the genetic of inherited colorblindness giving emphasis on novel molecular aspects such as splicing defects induced by exon 3 variants and gene conversion events underlying BCM.