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Molecular and Human Genetics

Houston, Texas

Department of Molecular and Human Genetics
Department of Molecular and Human Genetics
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Richard Alan Lewis, M.D., M.S.

Richard Alan Lewis, M.D., M.S.

Professor of Molecular and Human Genetics

Other Positions

Professor, Departments of Ophthalmology; Medicine; and Pediatrics
Faculty Associate, Huffington Center on Aging
Principal Investigator, Studies of the Ocular Complications of AIDS (LSOCA)
Member, National School of Tropical Medicine at Baylor College of Medicine


B.A., Harvard College, 1965
M.D., University of Michigan Medical School, 1969
M.S., University of Michigan, 1974

Research Interests

Dr. Lewis, an ophthalmologist at the Cullen Eye Institute and the Alkek Eye Center, is a consultant in genetic eye disorders to the Kleberg Genetics Center at Texas Children's Hospital and to the adult genetics services at the Baylor affiliated hospitals. His clinical practice of retinal and uveal diseases includes hereditary eye disease and the ocular manifestations of systemic hereditary disease. He pioneered the mapping of X-linked ocular diseases, including X-linked Retinitis Pigmentosa, Choroideremia, the Oculo-Cerebro-Renal Syndrome of Lowe, Blue Cone Monochromacy, X-linked (Nettleship-Falls) Ocular Albinism (OA1), and the Nance-Horan X-linked cataract-dental syndrome.

In collaboration with Dr. James Lupski, we have continued our studies of autosomal recessive ocular and retinal disorders, such as Stargardt Disease/Fundus Flavimaculatus (a form of juvenile macular degeneration), the (Laurence-Moon-)Bardet-Biedl syndrome (BBS combines retinal dystrophy, obesity, polydactylia, developmental retardation, and renal disease), Rod Monochromacy (complete congenital achromatopsia), and Leber Congenital Amaurosis (a group of disorders causing blindness from birth). BBS1, the most common form of BBS, was mapped here and BBS6, BBS7, BBS8, BBS10, and four others were identified here first. The gene for Stargardt disease was isolated and the role of this gene in Age-Related Macular Degeneration and autosomal recessive forms of retinitis pigmentosa were explored here first. The first human examples of digenic triallelic inheritance (in BBS) were defined from our BBS cohort.

In collaboration with Dr. David Nelson, we isolated the gene for Incontinentia Pigmenti (IP2) at Xq28, an X-dominant disorder with multisystem complications in the eye, skin, brain, and teeth in females, and embryonic lethality in most males. Further investigations are focused on the uncommon male "survivors" with IP and related unusual phenotypes with immunodeficiency. In collaboration with Dr. Igna Van den Veyver, the search for the genetic construct for Aicardi syndrome continues.

More recent investigations center on juvenile cataracts and sudden death in a selected U.S. religious isolate, photosternutation (photic sneezing), and the diverse causes of profound visual impairments in early life, including the microphthalmia-anophthalmia-coloboma (MAC) complex, optic nerve hypoplasia, ‘congenital optic atrophy’, septo-optic dysplasia sequence, and cortical visual impairment.

Dr. Lewis has been the Principal Investigator at Baylor College of Medicine for the Studies of the Ocular Complications of AIDS (SOCA) for more than 20 years. In addition, he was the Principal Investigator for the Age-Related Eye Disease Study 2 (AREDS2), a 5-year NEI program that demonstrated that nutritional supplementation of either lutein or fish oil (or both) did not reduce the risk of progression of macular degeneration in older Americans.

Advanced Retinitis Pigmentosa

Advanced retinitis pigmentosa. The narrowed blood vessels, the pale optic nerve, and the dense pigment migration into the retina are all features of the many human conditions with which retinitis pigmentosa has been associated.

Selected Publications

  1. Craigen WJ, Graham BH, Wong LJ, Scaglia F, Lewis RA, Bonnen PE (2013). Exome sequencing of a patient with suspected mitochondrial disease reveals a likely multigenic etiology. BMC Med. Genet. 14: 83. PubMed PMID: 23947751
  2. Cecchi A, Ogawa N, Martinez HR, Carlson A, Fan Y, Penny DJ, Guo DC, Eisenberg S, Safi H, Estrera A, Lewis RA, Meyers D, Milewicz DM (2013). Missense mutations in FBN1 exons 41 and 42 cause Weill-Marchesani syndrome with thoracic aortic disease and Marfan syndrome. Am. J. Med. Genet. A. 161(9): 2305-10. PubMed PMID: 23897642
  3. Age-Related Eye Disease Study 2 (AREDS2) Research Group, Chew EY, SanGiovanni JP, Ferris FL, Wong WT, Agron E, Clemons TE, Sperduto R, Danis R, Chandra SR, Blodi BA, Domalpally A, Elman MJ, Antoszyk AN, Ruby AJ, Orth D, Bressler SB, Fish GE, Hubbard GB, Klein ML, Friberg TR, Rosenfeld PJ, Toth CA, Bernstein P (2013). Lutein/zeaxanthin for the treatment of age-related cataract: AREDS2 randomized trial report no. 4. JAMA Ophthalmol. 131(7): 843-50. PubMed PMID: 23645227
  4. Age-Related Eye Disease Study 2 Research Group (2013). Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial. JAMA 309(19): 2005-15. PubMed PMID: 23644932
  5. Lewis RA (2013). Oculocutaneous Albinism Type 1. In GeneReviews at GeneTests: Medical Genetics Information Resource [database online]. Copyright, University of Washington, Seattle, 1997-2013. Available at
  6. Churchill JD, Bowne SJ, Sullivan LS, Lewis RA, Wheaton DK, Birch DG, Branham KE, Heckenlively JR, Daiger SP (2013). Mutations in the X-linked retinitis pigmentosa genes RPGR and RP2 found in 8.5% of families with a provisional diagnosis of autosomal dominant retinitis pigmentosa. Invest. Ophthalmol. Vis. Sci. 54(2): 1411-6. PubMed PMID: 23372056
  7. Branham K, Othman M, Brumm M, Karoukis AJ, Atmaca-Sonmez P, Yashar BM, Schwartz SB, Stover NB, Trzupek K, Wheaton D, Jennings B, Ciccarelli ML, Jayasundera KT, Lewis RA, Birch D, Bennett J, Sieving PA, Andreasson S, Duncan JL, Fishman GA, Iannaccone A, Weleber RG, Jacobson SG, Heckenlively JR, Swaroop A (2012). Mutations in RPGR and RP2 account for 15% of males with simplex retinal degenerative disease. Invest. Ophthalmol. Vis. Sci. 53(13): 8232-7. PubMed PMID: 23150612
  8. Lewis RA (2012). Oculocutaneous Albinism Type 2. In GeneReviews at GeneTests: Medical Genetics Information Resource [database online]. Copyright, University of Washington, Seattle, 1997-2012. Available at
  9. Fruhman G, Eble TN, Gambhir N, Sutton VR, Van den Veyver IB, Lewis RA (2012). Ophthalmologic findings in Aicardi syndrome. J. AAPOS 16(3): 238-41. PubMed PMID: 22681940
  10. Chaki M, Airik R, Ghosh AK, Giles RH, Chen R, Slaats GG, Wang H, Hurd TW, Zhou W, Cluckey A, Gee HY, Ramaswami G, Hong CJ, Hamilton BA, Cervenka I, Ganji RS, Bryja V, Arts HH, van Reeuwijk J, Oud MM, Letteboer SJ, Roepman R, Husson H, Ibraghimov-Beskrovnaya O, Yasunaga T, Walz G, Eley L, Sayer JA, Schermer B, Liebau MC, Benzing T, Le Corre S, Drummond I, Janssen S, Allen SJ, Natarajan S, O'Toole JF, Attanasio M, Saunier S, Antignac C, Koenekoop RK, Ren H, Lopez I, Nayir A, Stoetzel C, Dollfus H, Massoudi R, Gleeson JG, Andreoli SP, Doherty DG, Lindstrad A, Golzio C, Katsanis N, Pape L, Abboud EB, Al-Rajhi AA, Lewis RA, Omran H, Lee EY, Wang S, Sekiguchi JM, Saunders R, Johnson CA, Garner E, Vanselow K, Andersen JS, Shlomai J, Nurnberg G, Nurnberg P, Levy S, Smogorzewska A, Otto EA, Hildebrandt F (2012). Exome Capture Reveals ZNF423 and CEP164 Mutations, Linking Renal Ciliopathies to DNA Damage Response Signaling. Cell 150(3): 533-48. PubMed PMID: 22863007
  11. Brunetti-Pierri N, Lamance KM, Lewis RA, Craigen WJ (2012). 30-year follow-up of a patient with classic citrullinemia. Mol. Genet. Metab. 106(2): 248-50. PubMed PMID: 22494546

Contact Information

Richard A. Lewis, M.D., M.S.
Cullen Eye Institute
Baylor College of Medicine
One Baylor Plaza, MS NC205
Houston, TX, 77030, U.S.A.

Eye Clinic Appointments: 713-798-6100
Fax: 713-798-3042

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