Dwight E. Stambolian, MD, PhD

faculty photo
Associate Professor of Ophthalmology
Department: Ophthalmology
Graduate Group Affiliations

Contact information
Rm. 313 Stellar-Chance Labs
422 Curie Boulevard
Philadelphia, PA 19104-6069
Education:
BA
Lycoming College, Williamsport, PA, 1971.
M.D.
S.U.N.Y. Downstate at Syracuse, 1976.
Ph.D. (Genetics)
University of Pennsylvania, 1983.
Permanent link
 

Description of Research Expertise

Research Interests
Genome wide association studies of age-related macular degeneration and glaucoma; Next-generation targeted sequencing of age-related macular degeneration in African Americans; Genetics of age-related macular degeneration in the Amish; Whole exome sequencing of families with refractive error; Zebrafish modeling of refractive error and glaucoma; Characterization of mouse models for microphthalmia.

Key Words: Fun Lab, Bioinformatics galore, espirit de corps, collegial atmosphere, challenging projects, molecular genetics.

Description of Research:

Age-related macular degeneration (AMD) in African Americans
Much work has been accomplished on the genetics of AMD in Caucasians to the point that we currently have 10 well-defined loci identified by genome-wide association studies. While we have had amazing successes in Caucasians for AMD, very little has been done in African Americans probably because the disease is much rarer in this group. A GWAS study is not plausible in African Americans because of the decreased frequency of AMD. Therefore, we are using new DNA sequencing technology to identify the reasons that AMD is less severe in African Americans. We have collected a large cohort of African American cases and controls and are currently utilizing targeted next-gen sequencing to identify protective haplotypes that might offer an explanation of resistance to AMD development in African Americans. If these protective SNPs are found, they could serve as new potential drug targets.

Expression differences between normal and AMD eyes
We have been very successful in the identification of susceptibility genes for AMD through GWAS. The next horizon is to understand the expression differences between eyes with AMD and eyes that are normal. To identify differential expression between normal and AMD eyes, we have collected a series of postmortem eyes with and without AMD. RNA and DNA has been isolated from these eyes for the purpose of RNA sequencing and genotyping. Our underlying hypothesis is that there is a difference in normal transcript expression between normal and AMD eyes or a defect in alternative splicing that predisposes to AMD. The RNA-Seq data is being analyzed for expression differences as well as for alternative splicing defects with our new algorithm developed in the lab, SplicePL. Expression will also be correlated with known AMD risk SNPs to assess SNP potential to influence expression.

Genetics of AMD in the Amish
The genetics of AMD has been well studied in unrelated case-control Caucasian cohorts. However, very little has been done to identify genes in families. To that end, we have screened 3000 Amish individuals over the age of 50 years living in Lancaster County, Pa for various eye diseases including AMD. Every subject visiting the Amish clinic received a full eye exam, an epidemiology questionnaire, and a fundus photo along with the donation of a blood sample. We currently have DNA on all these individuals. Our collected Amish cohort currently consists of 750 nuclear families and has tremendous power to identify rare variants. We are currently preparing to do whole exome sequencing in selected families for the purpose of rare variant discovery in AMD. Discovery of rare AMD variants of large effect will have potential impact in the general population.

Genetics of Refractive Error
Refractive error is an abnormality of the eye that results in myopia, hyperopia or astigmatism. It is the leading cause of blindness worldwide. Most studies to date have centered on family linkage studies. Our lab is currently leading an international consortium to identify the genes for refractive error through GWAS and next-gen sequencing. We have just completed a GWAS of 7000 individuals with a few significant hits. We now seek to understand how these significant GWAS SNPs lead to the development of refractive error. We are currently utilizing bioinformatic tools to characterize the function of these SNPS and will move to functional studies in zebrafish after exhausting our bioinformatic tools. In addition, we have collected DNA from large families transmitting myopia and are preparing to perform whole exome sequencing to identify rare variants in these families.

Modeling of Human Disease in Zebrafish
We have developed a system in the lab to assess the refractive error phenotype in zebrafish embryos. Current experiments include knockdown and overexpression of various potential refractive error genes as a validation to the GWAS hits we have identified. Validated results in a zebrafish model will be followed by RNA-Seq of the mutants to provide a framework for a systems biology approach to understanding refractive error.

Characterization of Mouse Models for Microphthalmia
Over the past few years we have been characterizing a mouse model for microphthalmia (Tcm), a phenotype identified in a colony of X-ray irradiated mouse. Genetic mapping refined the causative locus to a 1.3Mb region on mouse Chromosome 4 which contains 5 genes. Further molecular characterization is underway in our lab to identify the founder mutation responsible for the microphthalmic phenotype.

Common techniques in the lab include bioinformatics, DNA cloning, PCR, agarose gel electrophoresis, in situ hybridization, DNA sequencing and library screening.

Lab Personnel:
Murthy Chavali
Eric Chen
Dave Collins
Debra Dana
Neil Farbman
Harini Gudiseva
Trafina Jadhav
Krista Kazmierkiewicz
Mijin Kim
Aishat Mohammed
Akshit Nayar
Poorva Sethi
Lifeng Tian
Stephanie Yee

Selected Publications

Sadigh Sam, Luo Xunda, Cideciyan Artur V, Sumaroka Alexander, Boxley Stacy L, Hall Laura M, Sheplock Rebecca, Feuer William J, Stambolian Dwight S, Jacobson Samuel G: Drusen and photoreceptor abnormalities in African-Americans with intermediate non-neovascular age-related macular degeneration. Current eye research 40(4): 398-406, Apr 2015.

Diniz B, Rodger D C, Chavali V R, MacKay T, Lee S Y, Stambolian D, Sadda S V R: Drusen and RPE atrophy automated quantification by optical coherence tomography in an elderly population. Eye (London, England) 29(2): 300, Feb 2015.

Li Qing, Wojciechowski Robert, Simpson Claire L, Hysi Pirro G, Verhoeven Virginie J M, Ikram Mohammad Kamran, Höhn René, Vitart Veronique, Hewitt Alex W, Oexle Konrad, Mäkelä Kari-Matti, MacGregor Stuart, Pirastu Mario, Fan Qiao, Cheng Ching-Yu, St Pourcain Beaté, McMahon George, Kemp John P, Northstone Kate, Rahi Jugnoo S, Cumberland Phillippa M, Martin Nicholas G, Sanfilippo Paul G, Lu Yi, Wang Ya Xing, Hayward Caroline, Polašek Ozren, Campbell Harry, Bencic Goran, Wright Alan F, Wedenoja Juho, Zeller Tanja, Schillert Arne, Mirshahi Alireza, Lackner Karl, Yip Shea Ping, Yap Maurice K H, Ried Janina S, Gieger Christian, Murgia Federico, Wilson James F, Fleck Brian, Yazar Seyhan, Vingerling Johannes R, Hofman Albert, Uitterlinden André, Rivadeneira Fernando, Amin Najaf, Karssen Lennart, Oostra Ben A, Zhou Xin, Teo Yik-Ying, Tai E Shyong, Vithana Eranga, Barathi Veluchamy, Zheng Yingfeng, Siantar Rosalynn Grace, Neelam Kumari, Shin Youchan, Lam Janice, Yonova-Doing Ekaterina, Venturini Cristina, Hosseini S Mohsen, Wong Hoi-Suen, Lehtimäki Terho, Kähönen Mika, Raitakari Olli, Timpson Nicholas J, Evans David M, Khor Chiea-Chuen, Aung Tin, Young Terri L, Mitchell Paul, Klein Barbara, van Duijn Cornelia M, Meitinger Thomas, Jonas Jost B, Baird Paul N, Mackey David A, Wong Tien Yin, Saw Seang-Mei,* Pärssinen Olavi,* Stambolian Dwight,* Hammond Christopher J,* Klaver Caroline C W,* Williams Cathy,* Paterson Andrew D,* Bailey-Wilson Joan E,* Guggenheim Jeremy A*. *These authors jointly directed the work.: Genome-wide association study for refractive astigmatism reveals genetic co-determination with spherical equivalent refractive error: the CREAM consortium. Human genetics 134(2): 131-46, Feb 2015.

Xiong Donghai, Wang Yian, Kupert Elena, Simpson Claire, Pinney Susan M, Gaba Colette R, Mandal Diptasri, Schwartz Ann G, Yang Ping, de Andrade Mariza, Pikielny Claudio, Byun Jinyoung, Li Yafang, Stambolian Dwight, Spitz Margaret R, Liu Yanhong, Amos Christopher I, Bailey-Wilson Joan E, Anderson Marshall, You Ming: A recurrent mutation in PARK2 is associated with familial lung cancer. American journal of human genetics 96(2): 301-8, Feb 2015.

Morrison Margaux A, Magalhaes Tiago R, Ramke Jacqueline, Smith Silvia E, Ennis Sean, Simpson Claire L, Portas Laura, Murgia Federico, Ahn Jeeyun, Dardenne Caitlin, Mayne Katie, Robinson Rosann, Morgan Denise J, Brian Garry, Lee Lucy, Woo Se J, Zacharaki Fani, Tsironi Evangelia E, Miller Joan W, Kim Ivana K, Park Kyu H, Bailey-Wilson Joan E, Farrer Lindsay A, Stambolian Dwight, DeAngelis Margaret M: Ancestry of the Timorese: age-related macular degeneration associated genotype and allele sharing among human populations from throughout the world. Frontiers in genetics 6: 238, 2015.

Kember Rachel L, Georgi Benjamin, Bailey-Wilson Joan E, Stambolian Dwight, Paul Steven M, Bućan Maja: Copy number variants encompassing Mendelian disease genes in a large multigenerational family segregating bipolar disorder. BMC genetics 16: 27, 2015.

Chavali Venkata Ramana Murthy, Diniz Bruno, Huang Jiayan, Ying Gui-Shuang, Sadda SriniVas R, Stambolian Dwight: Association of OCT derived drusen measurements with AMD associated-genotypic SNPs in Amish population. Journal of clinical medicine 4(2): 304-317, 2015.

Ratnapriya Rinki, Zhan Xiaowei, Fariss Robert N, Branham Kari E, Zipprer David, Chakarova Christina F, Sergeev Yuri V, Campos Maria M, Othman Mohammad, Friedman James S, Maminishkis Arvydas, Waseem Naushin H, Brooks Matthew, Rajasimha Harsha K, Edwards Albert O, Lotery Andrew, Klein Barbara E, Truitt Barbara J, Li Bingshan, Schaumberg Debra A, Morgan Denise J, Morrison Margaux A, Souied Eric, Tsironi Evangelia E, Grassmann Felix, Fishman Gerald A, Silvestri Giuliana, Scholl Hendrik P N, Kim Ivana K, Ramke Jacqueline, Tuo Jingsheng, Merriam Joanna E, Merriam John C, Park Kyu Hyung, Olson Lana M, Farrer Lindsay A, Johnson Matthew P, Peachey Neal S, Lathrop Mark, Baron Robert V, Igo Robert P, Klein Ronald, Hagstrom Stephanie A, Kamatani Yoichiro, Martin Tammy M, Jiang Yingda, Conley Yvette, Sahel Jose-Alan, Zack Donald J, Chan Chi-Chao, Pericak-Vance Margaret A, Jacobson Samuel G, Gorin Michael B, Klein Michael L, Allikmets Rando, Iyengar Sudha K, Weber Bernhard H, Haines Jonathan L, Léveillard Thierry, Deangelis Margaret M, Stambolian Dwight, Weeks Daniel E, Bhattacharya Shomi S, Chew Emily Y, Heckenlively John R, Abecasis Gonçalo R, Swaroop Anand: Rare and common variants in extracellular matrix gene Fibrillin 2 (FBN2) are associated with macular degeneration. Human molecular genetics 23(21): 5827-37, Nov 2014.

Li Mingyao, Jia Cheng, Kazmierkiewicz Krista L, Bowman Anita S, Tian Lifeng, Liu Yichuan, Gupta Neel A, Gudiseva Harini V, Yee Stephanie S, Kim Mijin, Dentchev Tzvete, Kimble James A, Parker John S, Messinger Jeffrey D, Hakonarson Hakon, Curcio Christine A, Stambolian Dwight: Comprehensive analysis of gene expression in human retina and supporting tissues. Human molecular genetics 23(15): 4001-14, Aug 2014.

Bourne Rupert R A, Jonas Jost B, Flaxman Seth R, Keeffe Jill, Leasher Janet, Naidoo Kovin, Parodi Maurizio B, Pesudovs Konrad, Price Holly, White Richard A, Wong Tien Y, Resnikoff Serge, Taylor Hugh R: Prevalence and causes of vision loss in high-income countries and in Eastern and Central Europe: 1990-2010. The British journal of ophthalmology 98(5): 629-38, May 2014.

back to top
Last updated: 08/29/2015
The Trustees of the University of Pennsylvania