TESS Foundation Funded Research Projects
The Na+/Citrate Transporter In Human Neurons.
Anne Murphy, PhD and Ana M. Pajor, PhD
University of California San Diego
In this project, Dr. Pajor, Dr. Murphy and their teams will investigate the effect of loss of SLC13A5 expression on transport of citrate and succinate in cultured human neurons. They plan to study the metabolic and bioenergetic consequences of this loss to understand how it results in the development of epilepsy.
“Dr. Pajor has been working on the citrate transporter family for many years. She is one of the many researchers the TESS Research Foundation has reached out to over the years to try and encourage members of the SLC13A5 research community to study transporter dysfunction in the nervous system. Her proposal is a collaboration that will lead us to an understanding of what the loss of transport means for neurons and how they might compensate to overcome the loss.” –Brenda Porter, MD, PhD, Stanford Children’s Health; TESS Research Foundation Scientific Advisory Board Member
Drug Discovery in Slc13a5 Mutant Zebrafish.
Deborah M. Kurrasch, PhD
University of Calgary
Over the past funding period, Dr. Kurrasch and her team developed a zebrafish model that harbors a frameshift mutation in slc13a5. In the proposed project, she will continue testing this zebrafish model to screen a new repurposed drug library and further validate the drugs uncovered in these screens.
“Funding from TESS Research Foundation has been instrumental in our work to find a therapy that helps SLC13A5-deficient children. Without their support, we could not do the work we do.” –Dr. Deborah Kurrasch
“Deb Kurrasch is an outstanding leader in drug screening and repurposing. Her high throughput screens are the best bet we have to identify an already FDA approved medication that can help kids with SLC13A5 Deficiency.” –Dr. Matthew Bainbridge
Creation Of Humanized Mouse And Fly Models Of SLC13A5 Mutant Syndrome To Determine The Cause Of Neurological Dysfunction And To Identify And Test Treatments.
Stephen L. Helfand, MD
In this project, Dr. Helfand and his collaborators aim to create a humanized mouse model in which a normal mouse SLC13A5 gene will be replaced by either a normal human SLC13A5 gene or a mutant human SLC13A5 gene. Dr Helfand has also created fly models of SLC13A5 and aims to study them further to pinpoint the physiological pathway that is affected due to SLC13A5 mutation. These mice and fly models will be instrumental in understanding how human SLC13A5 mutations cause neurological deficits and will be used to test and validate proposed treatments.
“Dr. Helfand has been a researcher interested in how loss of SLC13A5 in the liver is helpful for improved mouse survival. In the present study he will try to create a mouse that actually has introduced a human mutation in SLC13A5 allowing for us to better understand the pathophysiology of SLC13A5 in the brain.” — Dr. Brenda Porter
2015 – 2016
The Pajor Lab.
The main focus of the Pajor Lab is to understand the mechanism of sodium-coupled transporters, particularly the Na+/dicarboxylate cotransporters (NaDC) from the SLC13 family. A number of mutations have been identified in the NaCT transporter gene (SLC13A5) in patients with epileptic encephalography. The Pajor Lab explores what these mutations do to the function of NaCT. By studying the effects of these mutations, we may be able to identify a treatment for this disease.
SLC13A5 Bio-Bank at Stanford.
This project, spearheaded by Dr. Brenda Porter, creates a Bio-Bank of blood and skin samples of SLC13A5 patients and their parents. These blood and skin samples will be made available to researchers studying SLC13A5 and its role in epilepsy. Currently there are no animal models that recapitulate the neurological phenotype of SLC13A5. Ideally, the mechanisms underlying SLC13A5 mutations need to be studied in human patients and in their cells. Since neurons maintain the genetic profile of an individual, studying neurons derived from human induced pluripotent stem cells (hiPSC) is attractive as a method for studying neurons from SLC13A5 patients. A Bio-Bank is the first step in creating hiPSC and neuronal cell lines.
Baylor College of Medicine and Texas Children’s Hospital.
Dr. Brett Graham and Dr. Sarah Elsea are collaborating to screen and monitor metabolomic markers for SLC13A5 Deficiency and translate them into precision medicine. They have currently enrolled several patients with SLC13A5 mutations in a Triheptanoin drug trial. Triheptanoin, made by Ultragenyx, is intended to provide patients with medium-length, odd-chain fatty acids. Due to its odd-chain properties, triheptanoin is broken down into metabolites that replace deficient intermediates in the Citric Acid Cycle, a key energy-generating process that is likely disrupted by SLC13A5 mutations.
Our Scientific Advisory Board
Brenda Porter, MD, PhD
Dr. Porter is currently an Associate Professor of Neurology at Stanford University. She received her M.D. and Ph.D. from Washington University in St. Louis, and completed a residency in pediatrics at St. Louis Children’s Hospital; pediatric neurology and pediatric epilepsy at Children’s Hospital of Philadelphia. Dr. Porter is the treating physician for Tessa and Colton Nye. Now that a cause for Tessa and Colton’s seizures and other neurologic problems has finally been identified, Dr. Porter is focused on determining how to best treat them and other children with SLC13A5 mutations. It is her hope that through this website greater awareness will be raised for the disorder and increased communication amongst other affected families and the health care professionals providing treatment to their children. Dr. Porter is very interested in speaking with other doctors taking care of children with SLC13A5 mutations. She can be reached directly via email at firstname.lastname@example.org.
Matthew Bainbridge, PhD
Dr. Bainbridge is the President and CEO of Codified Genomics. Matthew has worked with high-throughput sequencing since its inception. At Canada’s Michael Smith Genome Sciences Centre (BCGSC), he constructed the first algorithms for RNA seq, chip-seq, and structural rearrangement discovery for the 454 and Solexa sequencing platforms. He later received his PhD in structural and computational biology and molecular biophysics from his work at the Baylor College of Medicine Human Genome Sequencing Center (BCM-HGSC). There he helped develop the BCM-HGSC’s illumina analysis pipeline, capture-resequencing analytics and co-developed capture reagents, both regional and whole exome including some of the largest capture targets ever sequenced. His analytic tools were central to the analysis of one the first personal genomes used for medical diagnostics[Lupski]. Later, he led the team that discovered the molecular cause of DRD in siblings. This information was used, for the first time, to alter the management and medications the children received. Later, he used WES to find a novel gene for a previously undescribed disease, marking one of the first times WES was used to molecularly describe a disease prior to its clinical description.
Tracy Dixon-Salazar, PhD
Dr. Dixon-Salazar’s desire to get her Ph.D. was inspired by her daughter who developed a severe epileptic encephalopathy at the age of 2 years old. She did her Ph.D. and post-doctoral work at the University of California, San Diego where she studied the mechanisms of brain development and synaptic plasticity, identified genetic causes of neurological disorders in children, and investigated precision therapeutics in cell-based and animal models of pediatric brain disease. During her post-doctoral fellowship, and after 16 years of watching daily, unrelenting seizures in her child, Dr. Dixon-Salazar’s research uncovered the driver of her daughter’s epilepsy and identified a precision therapy that saved her daughter’s life.
With more than 15 years of direct research experience, 18 years of non-profit experience, and 21 years caring for a child with a rare disease, Dr. Dixon-Salazar embodies the concept that patient-centered, patient-inclusive research is the key to meaningful medical solutions. She is an accomplished scientist, skilled strategist, highly sought-after speaker, and staunch advocate for rare disease, medical research, and patient-centricity.
Deepti Dubey, PhD
Dr. Dubey is scientific officer for TESS Research Foundation. She received her PhD from Indian Institute of Technology, Kanpur, India. She later did her postdoctoral training in the department of Neurology at Stanford University. Her research career is focused on understanding underlying molecular mechanisms of epileptic disorders including Lafora Disease, a rare genetic form of progressive myoclonus epilepsy and temporal lobe epilepsy induced by brain insults using cell and animal models. Dr. Dubey is interested in applying her research experience to facilitate understanding of rare genetic disorders like SLC13A5 deficiency along with exploring immediately available treatment options.
Brett Graham, MD, PhD
Dr. Graham is currently an Assistant Professor of Molecular and Human Genetics at Baylor College of Medicine. He received his M.D. and Ph.D. from Emory University School of Medicine and completed a residency in Pediatrics as well as a fellowship in Molecular and Human Genetics at Baylor College of Medicine. Dr. Graham’s clinical interests include Genetic Disorders and Metabolic Disorders. His research interests include studying the genetics of metabolic function and disease through the manipulation of model systems, particularly the mouse and the fruit fly, Drosophila melanogaster. Specifically, his lab is interested in the function of the mitochondrion in normal cellular biology and disease. By taking advantage of the strengths of each model system, his lab intends to dissect the pathophysiology of mitochondrial dysfunction to progress towards the ultimate goal of developing novel therapeutic strategies for diseases that exhibit mitochondrial dysfunction.