Dr. Simensen has a specific interest in the effects of genetic disease on development, cognition and neuropsychological functioning.   Currently he is serving on the research team that is investigating a wide variety of X-linked mental retardation disorders.  He has experience as a classroom teacher of children with developmentally disabilities, preparation of teachers for special education, and being the custodial grandparent of a child with special needs which provides insight and empathy for children and families

In 1999 he was selected to be a fellow in the Division on Mental Retardation of the American Psychological Association.  He has presented papers at various professional meetings and holds active membership in the American Psychological Association (Divisions: Neuropsychology, Mental Retardation and Pediatric Psychology), the International Neuropsychological Society, the American Association on Mental Retardation, and state organizations.

Selected Publications:

• Simensen RJ, Abidi F, Collins JS, Schwartz CE, Stevenson RE.  Cognitive functioning in Coffin-Lowry syndrome.  Clinical Genetics 61:299-304, 2002.

• Simensen RJ, Colby RS, Corning KJ.  A prenatal counseling conundrum: Mosaic trisomy 16. A case study presenting cognitive functioning and adaptive behavior.  Genetic Counseling 14:331-336, 2003.

• Cason AL, Ikeguchi Y, Skinner C, Wood TC, Holden KR, Lubs HA., Martinez F, Simensen RJ, Stevenson RE, Pegg AE, Schwartz CE. X-linked Spermine Synthase Gene (SMS) Defect: The First Polyamine Deficiency Syndrome. European Journal of Human Genetics 11:937–944, 2003.
• Simensen RJ, Stevenson RE, Rogers RC, Colby RS. Neurocognition in Cri-du-Chat Syndrome. Proceedings of the Greenwood Genetic Center, 23:13-16, 2004.
• Simensen RJ, Collins JS, Schroer RJ, Skinner CD, Stevenson RE. Trajectories of Adaptive Behavior on Low to Moderate Functioning Males with Autism. Proceedings of the Greenwood Genetic Center, 24:22-33, 2005.
• Stevenson RE, Abidi F, Skinner C, Simensen RJ, Lubs HA, Schwartz CE. X-Linked Mental Retardation: The Greenwood-Miami Study. Proceedings of the Greenwood Genetic Center, 24:39-40, 2005.
• Schwartz CE, May MM, Carpenter NJ, Rogers RC, Martin J, Bialer MG, Ward J, Sanabria J, Marsa S, Lewis J A, Echeverri R, Lubs HA, Voeller K, Simensen RJ, Stevenson RE. Allan-Herndon-Dudley Syndrome and the Monocarboxylate Transporter 8 (MCT8) Gene. American Journal of Human Genetics 77:41-53, 2005.
• Stevenson RE, Bennett CW, Abidi F, Kleefsra T, Porteous M, Simensen RJ, Lubs HA, Hamel, BCJ, Schwartz CE. Renpenning syndrome comes into focus. American Journal of Medical Genetics, Part A 134A,(4): 415-421, 2005.
• Bhat SS, Schmidt KR, Ladd S, Kim KC, Schwartz CE, Simensen RJ, DuPont BR, Stevenson RE, Srivastava AK. Disruption of DMD and deletion of ACSL4 causing developmental delay, hypotonia, and multiple congenital anomalies. Cytogenetic and Genome Research 112:170-175, 2006.
• Simensen RJ, Fisch GS. Mental Retardation. Contribution to: The 5 Minute Clinical Consult, M. R. Dambro (Ed). Williams & Wilkins, Baltimore, 700-701, 2006.
• Simensen RJ, Fisch GS. Fragile X Syndrome. Contribution to: The 5 Minute Clinical Consult, M. R. Dambro (Ed). Williams & Wilkins, Baltimore, 420-421, 2006.
• Simensen RJ, Marble M, Stevenson RE, May M, Schwartz C. Carrier expression in Pelizaeus-Merzbacher disease. Proceedings of the Greenwood Genetic Center 25:38-43, 2006.
• Friez MJ, Jones JR, Clarkson K, Lubs H, Abuelo A, Bier J-A B, Pai S, Simensen R, Williams C, Giampietro PF, Schwartz CE, Stevenson RE. Recurrent Infections, Hypotonia, and Mental Retardation Caused by Duplication of MECP2 and Adjacent Regions in Xq 28. Pediatrics 118:e1687-e1695, 2006.
• Tarpey PS, Stevens C, Teague J, Edkins S, O’Meara S, Avis T, Barthorpe S, Buck G, Butler A, Cole J, Dicks E, Gray K, Halliday K, Harrison R, Hills K, Hinton J, Jones D, Menzies A, Mironenko T, Perry J, Raine K, Richardson D, Shepard R, Small A, Tofts C, Varian J, West S, Widaa S, Yates A, Catford R, Butler J, Mallya U, Moon J, Luo Y, Dorkins H, Thompson D, Easton DF, Wooster R, Bobrow M, Carpenter N, Simensen RJ, Schwartz CE, Stevenson RE, Turner G, Partington M, Gecz J, Stratton MR, Futreal PA, Raymond FL. Mutations in the Gene Encoding the Sigma 2 Subunit of the Adaptor Protein 1 Complex, AP1S2, Cause X-Linked Mental Retardation. American Journal of Human Genetics 79:1119-1124, 2006.
• Schwartz CE, Tarpey PS, Lubs HA, Verloes A, May MM, Risheg H, Friez MJ, Futreal PA, Edkins S, Teague J, Briault S, Skinner C, Bauer-Carlin A, Simensen RJ, Joseph SM, Jones JR, Gecz J, Stratton MR, Raymond FL, Stevenson RE. The original Lujan syndrome family has a novel missense mutation (p. N1007S) in the MED12 gene. J Med Genet 44:472-477, 2007.
• Stevenson RE, Brasington CK, Skinner C, Simensen RJ, Spence JE, Kesler S, Reiss AL, Scwartz CE. Craniofacioskeletal syndrome: An X-linked dominant disorder with early lethality in males. American Journal of Medical Genetics, Part A 143A:2321-2329, 2007.
• Tarpey PS, Raymond FL, Nguyen LS, Rodriguez J, Hackett A, Vandeleur L, Smith R, Shoubridge C, Edkins S, Stevens C, O'meara S, Tofts C, Barthorpe S, Buck G, Cole J, Halliday K, Hills K, Jones D, Mironenko T, Perry J, Varian J, West S, Widaa S, Teague J, Dicks E, Butler A, Menzies A, Richardson D, Jenkinson A, Shepherd R, Raine K, Moon J, Luo Y, Parnau J, Bhat SS, Gardner A, Corbett M, Brooks D, Thomas P, Parkinson-Lawrence E, Porteous ME, Warner JP, Sanderson T, Pearson P, Simensen RJ, Skinner C, Hoganson G, Superneau D, Wooster R, Bobrow M, Turner G, Stevenson RE, Schwartz CE, Futreal PA, Srivastava AK, Stratton MR, Gécz J. Mutations in UPF3B, a member of the nonsense-mediated mRNA decay complex, cause syndromic and nonsyndromic mental retardation. Nature Genetics 39:1127-33, 2007.
• Fisch GS, Carpenter N, Howard-Peebles PN, Holden JJ, Tarleton J, Simensen R, Nance W. Studies of age-correlated features of cognitive-behavioral development in children and adolescents with genetic disorders. American Journal of Medical Genetics 143(20):2478-89, 2007.
• Bhat SS, Ladd S, Grass F, Spence JE, Brasington CK, Simensen RJ, Schwartz CE, DuPont BR, Stevenson RE, Srivastava AK. Letter to the Editor: Disruption of the IL1RAPL1 gene associated with a pericentromeric inversion of the X chromosome in a patient with mental retardation and autism. Clinical Genetics73:94-96, 2008.