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About Sickkids
About SickKids

Saadet Andrews, M.D., Ph.D., FCCMG

The Hospital for Sick Children
Staff Physician
Clinical and Metabolic Genetics

Research Institute
Project Investigator
Research Institute

University of Toronto
Associate Professor
Paediatrics

Associate Member
Institute of Medical Sciences


Phone: (416) 813-7654 Ext. 202402
Fax: (416) 813-4940
Email: saadet.andrews@sickkids.ca

Brief Biography

Brief Biography

  • MD- Ege University, Izmir, Turkey and Leopold-Franzens Innsbruck University, Innsbruck, Austria
  • Pediatric Residency- University of Istanbul, Istanbul, Turkey
  • Biochemical Genetics Fellowship, University of British Columbia, Vancouver, Canada
  • PhD- Free University Amsterdam, The Netherlands
  • Licentiate of the Medical Council of Canada, Ottawa, Ontario, Canada

Areas of Speciality 

Creatine deficiency disorders
Pyridoxine dependent epilepsy
Epilepsy genetics
Inherited neurotransmitter disorders
Neurometabolic disorders
Pediatric movement disorders

Research Interests

Research Interests

Dr. Saadet Andrews’ research focuses on creatine deficiency disorders, pyridoxine-dependent epilepsy and epilepsy genetics.

  • Andrews and her team characterized first knock-out aldh7a1 zebrafish to study neuropathogenesis of pyridoxine dependent epilepsy caused by mutations in ALDH7A1. This model will serve for drug screening to identify novel treatment for pyridoxine dependent epilepsy
  • Gene discovery for epilepsy and developmental delay in childhood
  • Gene discovery for neonatal encephalopathy

Selected Publications

Zabinyakov N, Bullivant G, Cao F, Fernandez Ojeda M, Jia ZP, Wen XY, Dowling JJ, Salomons GS, Mercimek-Andrews S. Characterization of the first knock-out aldh7a1 zebrafish model for pyridoxine-dependent epilepsy using CRISPR-Cas9 technology. PLoS One. 2017 Oct 20;12(10):e0186645. doi: 10.1371/journal.pone.0186645.

Bruun TUJ, DesRoches CL, Wilson D, Chau V, Nakagawa T, Yamasaki M, Hasegawa S, Fukao T, Marshall C, Mercimek-Andrews S. Prospective cohort study for identification of underlying genetic causes in neonatal encephalopathy using whole-exome sequencing. Genet Med. 2017 Aug 17. doi: 10.1038/gim.2017.129.

Hamdan FF, Myers CT, Cossette P, Lemay P, Spiegelman D, Laporte AD, Nassif C, Diallo O, Monlong J, Cadieux-Dion M, Dobrzeniecka S, Meloche C, Retterer K, Cho MT, Rosenfeld JA, Bi W, Massicotte C, Miguet M, Brunga L, Regan BM, Mo K, Tam C, Schneider A, Hollingsworth G; Deciphering Developmental Disorders Study, FitzPatrick DR, Donaldson A, Canham N, Blair E, Kerr B, Fry AE, Thomas RH, Shelagh J, Hurst JA, Brittain H, Blyth M, Lebel RR, Gerkes EH, Davis-Keppen L, Stein Q, Chung WK, Dorison SJ, Benke PJ, Fassi E, Corsten-Janssen N, Kamsteeg EJ, Mau-Them FT, Bruel AL, Verloes A, Õunap K, Wojcik MH, Albert DVF, Venkateswaran S, Ware T, Jones D, Liu YC, Mohammad SS, Bizargity P, Bacino CA, Leuzzi V, Martinelli S, Dallapiccola B, Tartaglia M, Blumkin L, Wierenga KJ, Purcarin G, O'Byrne JJ, Stockler S, Lehman A, Keren B, Nougues MC, Mignot C, Auvin S, Nava C, Hiatt SM, Bebin M, Shao Y, Scaglia F, Lalani SR, Frye RE, Jarjour IT, Jacques S, Boucher RM, Riou E, Srour M, Carmant L, Lortie A, Major P, Diadori P, Dubeau F, D'Anjou G, Bourque G, Berkovic SF, Sadleir LG, Campeau PM, Kibar Z, Lafrenière RG, Girard SL, Mercimek-Mahmutoglu S, Boelman C, Rouleau GA, Scheffer IE, Mefford HC, Andrade DM, Rossignol E, Minassian BA, Michaud JL. High Rate of Recurrent De Novo Mutations in Developmental and Epileptic Encephalopathies. Am J Hum Genet. 2017 Nov 2;101(5):664-685.

Al Teneiji A, Bruun TU, Cordeiro D, Patel J, Inbar-Feigenberg M, Weiss S, Struys E, Mercimek-Mahmutoglu S. Phenotype, biochemical features, genotype and treatment outcome of pyridoxine-dependent epilepsy. Metab Brain Dis. 2017 Apr; 32(2):443-451.

Lionel AC, Monfared N, Scherer SW, Marshall CR, Mercimek-Mahmutoglu S. MED23-associated refractory epilepsy successfully treated with the ketogenic diet. Am J Med Genet A. 2016;170(9):2421-5.

Madeo M, Stewart M, Sun Y, Sahir N, Wiethoff S, Chandrasekar I, Yarrow A, Rosenfeld JA, Yang Y, Cordeiro D, McCormick EM, Muraresku CC, Jepperson TN, McBeth LJ, Seidahmed MZ, El Khashab HY, Hamad M, Azzedine H, Clark K, Corrochano S, Wells S, Elting MW, Weiss MM, Burn S, Myers A, Landsverk M, Crotwell PL, Waisfisz Q, Wolf NI, Nolan PM, Padilla-Lopez S, Houlden H, Lifton R, Mane S, Singh BB, Falk MJ, Mercimek-Mahmutoglu S, Bilguvar K, Salih MA, Acevedo-Arozena A, Kruer MC. Loss-of-Function Mutations in FRRS1L Lead to an Epileptic-Dyskinetic Encephalopathy. Am J Hum Genet. 2016;98(6):1249-55.

DesRoches CL, Bruun T, Wang P, Marshall CR, Mercimek-Mahmutoglu S. Arginine-Glycine Amidinotransferase Deficiency and Functional Characterization of Missense Variants in GATM. Hum Mutat. 2016;37(9):926-32

Mercimek-Mahmutoglu S, Salomons, GS. Creatine deficiency syndromes. In: Pagon RA, Adam MP, Ardinger HH, Wallace SE, Amemiya A, Bean LJH, Bird TD, Fong CT, Mefford HC, Smith RJH, Stephens K, editors. Source GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2015. 2009 Jan 15 [updated 2015 Dec 10]. Senior Responsible Author.

Marras C, Lang A, van de Warrenburg BP, Sue C, Tabrizi SJ, Bertram L, Lohmann K, Mercimek-Mahmutoglu S, Ebrahimi-Fakhari D, Warner TT, Durr A, Assmann B, Kostic V, Klein C. Nomenclature of Genetic Movement Disorders: Recommendations of the International Parkinson and Movement Disorder Society Task Force.  Mov Disord. 2016;31(4):436-57.

Patel J, Mercimek-Mahmutoglu S. Epileptic Encephalopathy in Childhood: A Stepwise Approach for Identification of Underlying Genetic Causes. Indian J Pediatr. 2016;83(10):1164-74.

Mercimek-Mahmutoglu S, Pop A, Kanhai W, Fernandez MO, Holwerda U, Smith D, Loeber, Schielen P, Salomons GS. A pilot study to estimate incidence of guanidinoacetate methyltransferase deficiency in newborns by direct sequencing of the GAMT gene. Gene. 2016;575:127-31.

Desroches CL, Patel J, Wang P, Minassian B, Marshall CR, Salomons GS, Mercimek-Mahmutoglu S. Carrier frequency of guanidinoacetate methyltransferase deficiency in the general population by functional characterization of missense variants in the GAMT gene. Molecular Genetics and Genomics. 2015;290:2163-71.

DesRoches C, Patel J, Wang P, Minassian B, Salomons GS, Marshall CR, Mercimek-Mahmutoglu S. Estimated carrier frequency of creatine transporter deficiency in the general female population using functional characterization of novel missense variants in the SLC6A8 gene. Gene. 2015;565:187-91.

Mercimek-Mahmutoglu S, Sidky S, Hyland K, Patel J, Donner E, Logan W, Mendoza-Londono R, Mahendranath M, Raiman J, Schulze A, Siriwardena K, Yoon G, Kyriakopolou L.  Prevalence of inherited neurotransmitter disorders in patients with movement disorders and epilepsy: a retrospective cohort study. Orphanet J Rare Dis. 2015 Feb 8;10:12. doi: 10.1186/s13023-015-0234-9.

Mercimek-Mahmutoglu S, Patel J, Cordeiro D, Hewson S, Callen D, Donner EJ, Hahn CD, Kannu P, Kobayashi J, Minassian B, Moharir M, Siriwardena K, Weiss SK, Weksberg R, Snead OC. Diagnostic yield of genetic testing in epileptic encephalopathy in childhood. Epilepsia. 2015;56:707-16.

Mercimek-Mahmutoglu S, Cordeiro D, Cruz V, Hyland K, Struys EA, Kyriakopoulou L, Mamak E.  Novel therapy for pyridoxine dependent epilepsy due to ALDH7A1 genetic defect: Larginine supplementation alternative to lysine-restricted diet. European Journal of Paediatric Neurology. 2014;18:741-6.

Mercimek-Mahmutoglu S, Ndika J, Kanhai W, de Villemeur TB, Cheillan D, Christensen E, Dorison N, Hannig V, Hendriks Y, Hofstede FC, Lion-Francois L, Lund AM, Mundy H, Pitelet G, Raspall-Chaure M, Scott-Schwoerer JA, Szakszon K, Valayannopoulos V, Williams M, Salomons GS. Thirteen new patients with guanidinoacetate methyltransferase deficiency and functional characterization of nineteen novel missense variants in the GAMT gene.  Human Mutation.  2014;35:462-9.

Mercimek-Mahmutoglu S, Sinclair G, van Dooren SJ, Kanhai W, Ashcraft P, Michel OJ, Nelson J, Betsalel OT, Sweetman L, Jakobs C, Salomons GS.  Guanidinoacetate methyltransferase deficiency: First steps to newborn screening for a treatable neurometabolic disease. Molecular Genetics and Metabolism.  2012;107:433-7.