1. Characterization of a new genetic disorder associated with hemiplagic migraines, coma, progressive spasticity, weakness, seizure disorder, spinal cord atrophy, and systemic serotonin deficiency. The research of a family with the above described phenotype lead to discovery of a new gene that involves cytoskeletal and axonal transport, and will cause cytoskeletal aggregates in neurons, that will keep neurotransmitter transporters (serotonin transporter) and other membrane expressed proteins (e.g. Na/K ATPase). This disorder has similarities with ALS, and could be a major breakthrough in ALS research. this research is done partly in collaboration with Dr. Randy Blakely at the Vanderbilt University in Nashville, who has done the exome sequencing in the family. I spent 6 weeks in his lab to do the molecular and biochemical studies. Before traveling there I developed a radioactive isotope method for measuring the serotonin trasnporter activity in vitro in these patients.
2. Neurotransmitter changes in patients with presyncope, in collaboration with Dr. Shubayan Sanatani (BCCH) and Dr. Victoria Claydon (SFU) I evaluate pateints in clinic with complex autonomic dysfunction and presyncope, and then enroll them in this study where they have sophisticated investigations with a tilt table test at the SFU Kinesiology Lab. I work on the plasma catecholamine and serotonin level interpretations in relation to the other test findings.
3. Neurotransmitter and parasympathetic response in patients with dysautonomia, in collaboration with Dr. Jean-Paul Collet (CFRI). I follow several patients with dysautonomia in clinic, who had their baseline catecholamine measurements and then enroll them in this study to evaluate the effect of Chines massage therapy and Tai-Chi on their parasymapthetic nervous system.
4. Biochemical findings in intractable epilepsy patients, looking at CSF metabolomics (280 metabolites) in collaboration with Dr. David Wishart (Alberta University) The results will help with diagnosis of the underlying metabolic/genetic disease.
5. Metabolic characterization of patients with unkown metabolic disorders for exome sequencing in the TIDE study, in collaboration with Dr. Sylvia Stockler-Ipsiroglu. Patients enrolled have to have a previously well defined biochemical phenotype, so the interpretation of the genetic results are easier. We have identified a new gene causing intermittent lactic keto-acidosis and hyperammonemia in one of my patients.
1. Horvath GA, Armstrong L. Report of a Fourth Individual with a Lethal Syndrome of Choanal Atresia, Athelia, Evidence of Renal Tubulopathy, and Family History of Neck Cysts. American Journal of Medical Genetics, Part A, Vol. 143A, Issue 11, pg. 1231-1235, 2007.
2. Horvath GA, Stockler-Ipsiroglu SG, Salvarinova-Zivkovic R, Lillquist YP, Connolly M, Hyland K, Blau N, Rupar T, Waters PJ. Autosomal recessive GTP-Cyclohydrolase I deficiency without hyperphenylalaninemia: Evidence of a phenotypic continuum between dominant and recessive forms. Molecular Genetics and Metabolism, 94, issue 1, May 2008:127-131, online published Feb 2008.
3. Horvath GA, Davidson AGF, Stockler-Ipsiroglu SG, Lillquist YP, Waters PJ, Olpin S, Andresen BS, Palaty J, Nelson J, Vallance H. Newborn screening for MCAD Deficiency. Experience of the first three years in British Columbia, Canada. Canadian Journal of Public Health 2008 Jul-Aug; 99(4):276-80
4. Horvath GA, Selby K, Poskitt K, Hyland K, Waters PJ, Coulter-Mackie M, Stockler-Ipsiroglu SG. Hemiplegic migraines, seizures, progressive spastic paraparesis, myelopathy, and mood disorder in siblings with low systemic serotonin: Cephalgia, Accepted, July 2011, IF 4.265 (published on-line Oct 2011).
5. Horvath GA, Eichler F, Poskitt K, Stockler-Ipsiroglu SG. Failure of repeated cyclophosphamide pulse therapy in childhood cerebral X-linked adrenoleukodystrophy. Submitted to Neuropediatrics, September 2011. Accepted by Neuropediatrics, December 2011.
Rare Diseases Foundation:in vivo Phosphorus Magnetic Resonance Spectroscopy of the Muscle in Two Siblings with Unexplained Muscle Weakness, 2009
Rare Diseases Foundation: Molecular Genetic Analysis of the MMSD Gene in a Patient with Recurrent Metabolic Coma and Abnormal Urinary Excretion of 3-Hydroxyisobutyric Acid, 2009
Rare Diseases Foundation: Evaluation of choline and acetylcholine pathways in a child with progressive cholinergic failure, 2010
Rare Diseases Foundation: Mitochondrial CK molecular studies in 2 siblings with muscle weakness with abnormal muscle MRS findings, 2010
Rare Diseases Foundation: Evaluation of platelet serotonin transporter and other membrane proteins in two siblings with familial hemiplegic migraines and a neurodegenerative disease, 2010
Rare Diseases Foundation: Platelet proteomic analysis in two siblings with familial hemiplegic migraines and a neurodegenerative disease, 2011
Rare Diseases Foundation: CSF metabolomic analysis in intractable epilepsy, 2011
Honours & Awards
Outstanding Achievement by a Clinical Subspecialty Resident or Fellow, UBC, June 16, 2006.
Wyett Excellence in Clinical Research, UBC, Resident Research Award 2006, July 2006
Laura MacRae Award 2007 (awarded to outstanding graduate student in the Dept. of Pediatrics, UBC, by the College of Physicians and Surgeons of British Columbia, June 2007
Rookie of the Year 2007, (awarded by the Pediatric Residents, UBC, at the Annual Graduation and Awards Dinner), June 2007.
Clinical Investigator Program, two year scholarship awarded (July 2008 to June 2010)