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Xilma R. Ortiz-Gonzalez, MD, PhD
Xilma R. Ortiz-Gonzalez
Attending Physician

Dr. Ortiz-Gonzalez is a physician-scientist specializing in pediatric neurogenetics. Her clinical work focuses on finding a unifying genetic diagnosis for children with rare neurodevelopmental disorders. Her research is informed by her patients and focuses on understanding how genetic changes, in particular those affecting mitochondrial function, cause disease so we can develop better treatments for these children in the future.



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Dr. Ortiz-Gonzalez developed an interest in mitochondrial disease and learned from the families she saw in clinic the long and difficult journey that many have endured just to obtain a genetic diagnosis. She focuses her clinical efforts in neurogenetics and continues to pursue additional research in mitochondrial biology.

Specifically, her research focuses on developing patient-derived stem cells to better understand why neurons and heart cells seem particularly affected by mitochondrial disease. Dr. Ortiz-Gonzalez is also interested in how mitochondrial dysfunction may lead to neurodegeneration in children affected with rare disorders. Her clinical work led to the co-discovery of the syndrome caused by mutations in the gene TBCK. She continues to work in trying to understand why patients with changes in this gene have neurologic symptoms, in particular why children with the Boricua mutation seem to have a neurodegenerative course. Her long-term goal is to develop new disease models that inform the cause of these rare genetic disorders, with the hope that better therapies can ultimately be developed for the affected children.

Dr. Ortiz-Gonzalez’s notable accomplishments include:

  • Collaborating to identify TBCK as a novel disease gene, and characterizing the systemic and neuromuscular symptoms in patients with the Boricua TBCK mutation
  • Identifying the new clinical syndromes due to gene mutations that usually present with epilepsy, intellectual disability and/or neuromuscular weakness in children. Some of the new disease genes identified from patients in the neurogenetics clinic: TBCK, SPTBN4, RHOBT2, MED13, GRIN2D, CHD3, SPATA5. Some of these discoveries have been translated into personalized treatments for patients
  • Working in human stem cell models of heart disease due to genetic defects affecting mitochondrial function (ANT1 cardiomyopathy)
  • Establishing that adult bone marrow cells were cabable of generating other tissues in the body (pluripotency), including neurons, at a time when this was a challenge to scientific dogma


Education and Training

BS, University of Puerto Rico, Cayey Campus (Chemistry), 1997

PhD, University of Minnesota (Neuroscience), 2004

MD, University of Minnesota, 2006

Pediatric Residency, Children's Hospital of Philadelphia, 2006-2011

Child Neurology Residency, Children's Hospital of Philadelphia, 2006-2011

Titles and Academic Titles

Attending Physician

Assistant Professor of Pediatrics

Assistant Professor of Neurology

Professional Memberships

Society for Neuroscience, 2001-

American Academy of Neurology, 2008-

United Mitochondrial Disease Foundation, 2011-

Mitochondrial Medicine Society, 2012-

Child Neurology Society, 2015-

SILAMP, Society for Ibero-Latinoamerican Medical Professionals, 2015-

American Neurological Association, 2017-

Professional Awards

Society for Neuroscience Minority Scholar Fellow, 2001-2004

National Research Service Award (NRSA) Predoctoral Fellow, NINDS, 2002-2006

Neurological Sciences Academic Development Award (NSADA), NIH, 2013-2016

Harold Amos Medical Faculty Development Award, RWJ Foundation, 2015

United Mitochondrial Disease Foundation- Kelsey Wright Award for Excellence in Mitochondrial Medicine, 2017

Publication Highlights

Ortiz-Gonzalez XR, Tintos-Hernandez JA, Keller K, Li X, Foley AR, Bharucha-Goebel DX, Kessler SK, Yum SW, Crino PB, He M, Wallace DC, & Bonnemann CG. Homozygous Boricua TBCK Mutation Causes Neurodegeneration and Aberrant Autophagy. Ann. Neurol. 2018 Nov; 83:153-165
King MS, Thompson K, Hopton S, He L, Kunji ERS, Taylor RW, & Ortiz-Gonzalez XR. Expanding the phenotype of de novo SLC25A4-linked mitochondrial disease to include mild myopathy. Neurol Genet. 2018 Jul; 4(4):e256
Wang CC, Ortiz-Gonzalez XR, Yum SW, Gill SM, White A, Kelter E, Seaver LH, Lee S, Wiley G, Gaffney PM, Wierenga KJ, & Rasband MN. βIV Spectrinopathies Cause Profound Intellectual Disability, Congenital Hypotonia, and Motor Axonal Neuropathy. Am. J. Hum. Genet. 2018 Jun; 102(6):1158-1168
Chong JX, Caputo V, Phelps IG, Stella L, Worgan L, Dempsey JC, Nguyen A, Leuzzi V, Webster R, Pizzuti A, Marvin CT, Ishak GE, Ardern-Holmes S, Richmond Z, University of Washington Center for Mendelian G, Bamshad MJ, Ortiz-Gonzalez XR, Tartaglia M, Chopra M, & Doherty D. Recessive Inactivating Mutations in TBCK, Encoding a Rab GTPase-Activating Protein, Cause Severe Infantile Syndromic Encephalopathy. Am. J. Hum. Genet. 2016 Apr; 98(4):772-781
Keene CD, Ortiz-Gonzalez XR, Jiang Y, Largaespada DA, Verfaillie CM, & Low WC. Neural differentiation and incorporation of bone marrow-derived multipotent adult progenitor cells after single cell transplantation into blastocyst stage mouse embryos. Cell Transplant. 2003 Jan; 12(3):201-213

Links of Interest