David Chitayat

Professor David Chitayat obtained his MD, Summa Cum Laude Absoluto from Tel-Aviv University, Sackler School of Medicine.  After graduating from medical school, he served in the Israeli Defense Force and was promoted to the position of a Major.  He completed his residency in Pediatrics at the Tel-Aviv Municipal Medical Center and did his fellowship in Medical Genetics at the Genetic Counselling Program at Albert Einstein School of Medicine, The Yeshiva University, NY, NY, USA and at the Department of Medical Genetics, University of British Columbia, BC, Canada.  He joined the Department of Pediatrics, Division of Clinical Genetics, McGill University in 1989 and in 1991 joined the Division of Clinical and Metabolic Genetics at The hospital for Sick Children and the Prenatal Diagnosis and Medical Genetics Program at Toronto General Hospital and later at Mount Sinai Hospital.  Some of his current posts include, Medical Director of The MSc Program in Genetic Counselling, University of Toronto; Head, The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital and Staff, Division of Clinical and Metabolic Genetics, Department of Pediatrics; University of Toronto.

Dr. Chitayat is a Professor in the Departments of Pediatrics, Molecular and Medical Genetics, Obstetrics and Gynecology and Laboratory Medicine and Pathobiology and is a fellow of the American Board of Medical Genetics, The Canadian College of Medical Genetics, The Royal College of Physicians and Surgeons of Canada and the American College of Medical Genetics. 

Dr. Chitayat has published over 15 book chapters and nearly 300 peer reviewed papers. He has been an invited visiting professor, and a keynote speaker at national and international universities and institutions. 

Research Synopsis

The recent breakthroughs in molecular genetics are heavily dependent on intense collaboration with top level clinical geneticists who are able to define and delineate the clinical phenotpe of the conditions investigated.  There are very few clinical geneticists in Canada devoted to and capable of supporting the current intense research in medical genetics and I am one of them (see Appendix).  My research contributions have centered on generating research questions based on interesting clinical cases and on translation of basic research findings to clinical practice.  This work primarily deals with detection of different fetal abnormalities on ultrasound, molecular, chromosome analysis and fetal autopsy and postnatal newborns/children with different conditions and identifying the responsible gene mutations causing them, in collaboration with different research laboratories.  My unique role in genetic research is highlighted through the following example:

Identifying the gene (transmembrane natriuretic peptide receptor NPR-B) causing acromesomelic dysplasia, type Maroteaux (AJHG 2004: 75:27-34). 

The long-term prognosis of cases with mosaicism 45,X/46,XX and 45,X/46,XY is an important theme in my research. Many pregnancies with mosaicism 45,X/46,XX are terminated due to the lack of knowledge regarding the clinical manifestations and long-term prognosis of this condition. Research has shown that almost all babies with this chromosome abnormality are normal females. Further follow-up is being conducted through the MUG clinic, to find the implications of this chromosome abnormality on their pubertal development and reproduction. Similarly, many cases with mosaicism 45,X/46,XY detected prenatally resulted in pregnancy termination based on the biased finding that this chromosome abnormality is associated with ambiguous genitalia among other abnormalities.  We found that most cases with this chromosome abnormality are normal males. We are currently following these patients to find whether they have an increased incidence of gonadoblastoma.Providing information regarding the clinical implications of prenatally diagnosed liver calcifications, (UOG 2006:  27:325-30), cardiac calcifications (Prenat Diagn 2005:  25: 539-42) and Cavum veli interpositi (Prenat Diagn 2005: 25: 539-42).

Recent Publications

Okun N, Sierra S; Genetics Committee, Wilson RD, Audibert F, Brock JA, Campagnolo C, Carroll J, Cartier L, Chitayat D, Gagnon A, Johnson JA, Langlois S, Murphy-Kaulbeck L, Macdonald WK, Okun N, Pastuck M; Special Contributors, Tan LY, Poplak V, Robson H: Pregnancy outcomes after assisted human reproduction.  J Obstet Gynaecol Can 2014: 36 (1): pp 64-83.

Wang DC, Shannon P, Toi A, Chitayat D, Mohan U, Barkova E, Keating S, George T, Glanc P: Temporal Lobe Dysplasia: A Characteristic Sonographic Finding in Thanatophoric Dysplasia.  [Epub ahead of print].  Ultrasound Obstet Gynecol 2014.

Aiyar L, Shuman C, Hayeems R, Dupuis A, Pu S, Wodak S, Chitayat D, Velsher L, Davies J: Risk estimates for complex disorders: comparing personal genome testing and family history.  Genetics in Medicine 2014: 16 (3): pp 231-237.

Inbar-Feigenberg M, Meirowitz N, Nanda D, Toi A, Okun N, Chitayat D: Beals syndrome (congenital contractural arachnodactyly) - Prenatal Ultrasound Findings and Molecular analysis.  [Epub ahead of print].  Ultrasound in Obstetrics and Gynecology 2014.

Moalem S, Brouillard P, Kuypers D, Legius E, Harvey E, Taylor G, Francois M, Vikkula M, Chitayat D: Hypotrichosis-Lymphedema-Telangiectasia-Renal defect Associated with a truncating mutation in the SOX18 gene.  [Epub ahead of print].  Clinical Genetics 2014.

Roifman M, Marcelis C, Paton T, Marshall C, Silver R, Lohr J, Yntema H, Venselaar H, Kayserili H, van Bon B, Seaward G; FORGE Canada Consortium, Brunner H, Chitayat D: De novo WNT5A-associated autosomal dominant Robinow syndrome suggests specificity of genotype and phenotype.  [Epub ahead of print].  Clinical Genetics 2014.

Madjunkova S, Tong Li C, Vlasschaert M, Adams M, Chitayat D, Maire G, Kolomietz E: QF-PCR rapid aneuploidy screen and aCGH analysis of cell free fetal (cff) DNA in supernatant of compromised amniotic fluids (AF). [Epub ahead of print].  Prenatal Diagnosis 2014.

Barkova E, Mohan U, Chitayat D, Keating S, Toi A, Frank J, Frank R, Tomlinson G, Glanc P: Fetal Skeletal Dysplasias in a Tertiary Care Centre: Radiology, Pathology, and Molecular Analysis of 112 cases. [Epub ahead of print].  Clinical Genetics 2014.

Weber R, Kantor P, Chitayat D, Friedberg MK, Golding F, Mertens L, Nield LE, Ryan G, Seed M, Yoo SJ, Manlhiot C, Jaeggi E: Spectrum and Outcome of Primary Cardiomyopathies Diagnosed During Fetal Life.  [Epub ahead of print].  JACC Heart Fail 2014.

Guo A, Chitayat D, Blaser S, Keating S, Shannon P: Fetal syringomyelia.  Acta Neuropathol Commun.  Acta neuropathologica communication 2014: 2: pp 91.

Jones CA, Kolomietz E, Maire G, Vlasschaert M, Joseph-George AM, Myles-Reid D, Chong K, Chitayat D, Arthur R: PGD for a carrier of an intrachromosomal insertion using aCGH.  Systems Biology in Reproductive Medicine 2014: 23: pp 1-6.

Yuen M, Sandaradura SA, Dowling JJ, Kostyukova AS, Moroz N, Quinlan KG, Lehtokari VL, Ravenscroft G, Todd EJ, Ceyhan-Birsoy O, Gokhin DS, Maluenda J, Lek M, Nolent F, Pappas CT, Novak SM, D'Amico A, Malfatti E, Thomas BP, Gabriel SB, Gupta N, Daly MJ, Ilkovski B, Houweling PJ, Davidson AE, Swanson LC, Brownstein CA, Gupta VA, Medne L, Shannon P, Martin N, Bick DP, Flisberg A, Holmberg E, Van den Bergh P, Lapunzina P, Waddell LB, Sloboda DD, Bertini E, Chitayat D, Telfer WR, Laquerri'e8re A, Greg: Leiomodin-3 dysfunction results in thin filament disorganization and nemaline myopathy.  [Epub ahead of print].  Journal of Clinical Investigation 2014. 

Wilson RD; SOGC Genetics Committee, Wilson RD, Audibert F, Brock JA, Campagnolo C, Carroll J, Cartier L, Chitayat D, Gagnon A, Johnson JA, Langlois S, MacDonald WK, Murphy-Kaulbeck L, Okun N, Pastuck M; Special Contributors, Popa V: Prenatal screening, diagnosis, and pregnancy management of fetal neural tube defects.  Journal of Obstetrics and Gynaecology Canada 2014: 36 (10): pp 927-939.

Reich A, Bae AS, Barnes AM, Cabral WA, Hineks A, Stimec J, Hill SC, Chitayat D, Marini JC: Type V OI primary osteoblasts display increased mineralization despite decreased COL1A1 expression. [Epub]. The Journal of Clinical Endocrinology and Metabolism 2014.

Appointments

Grants

2014

Genetic and Epigenetic Determinants of Syndromic Intellectual Disability.  Weksberg, R, Chitayat D, Ray P: Canadian Institutes of Health Research (CIHR) ($750,400 2013 - 2018)

Computerized Patient Phenotyping to Connect Canadian Clinical Genetics Clinics.  Brudno M, Boycott K, Bowdin S, Chitayat D: CIHR ($423,000 2013 - 2014)

Ascertaining the genetic etiologies of stillbirth via whole exome sequencing.  Meyn MS, Stavropoulos J, Chitayat D, Chong K, Shannon P, Keating S, Kolomietz E, Maire G: Accelerator Grant, McLaughlin Centre at the University of Toronto ($40,000 2014 - 2015)