February 2019

RCIGM Scientists Detect Cause of Rare Pediatric Brain Disorder

Rady Children’s Institute for Genomic Medicine Leads Mutation Discovery

Feb. 20, 2019—An international effort led by physician-scientists at Rady Children’s Institute for Genomic Medicine (RCIGM) has identified the cause of a devastating pediatric brain disorder paving the way for the first step in developing potential therapies for this rare neurodegenerative condition.

Investigators performed advanced genetic tests on blood samples from seven children with neuro-development disabilities who were evaluated by doctors in San Diego, Montreal and Cairo. This led to the discovery of mutations in the VARS gene, which had not previously been linked to human disease.

“These children showed epileptic seizures and abnormalities evident on brain MRI scans,” said Joseph Gleeson, MD, director of neurodevelopmental genetics at RCIGM and professor of neuroscience and pediatrics at UC San Diego School of Medicine. “Although no treatment currently exists for this condition, the results are important as the first step in guiding research directed at targeted therapies.”   

The genetic mutations identified in the study led to a defect in the enzyme responsible for generating proteins containing the amino acid valine which is necessary for cellular health. Genetic variations that damage these types of enzymes are associated with a variety of human diseases including microcephaly and neuropathy.

In this study, the team found that, enzymatic activity was significantly reduced in cells from the young patients. The findings suggest that children with this disorder may benefit from treatments to support the synthesis of new valine containing proteins in the brain.

For many children with genetic disabilities, the cause of their disease is never identified. This limits the ability of doctors to develop precise treatment plans. Researchers at RCIGM have pioneered the use of Whole Genome Sequencing to rapidly diagnose and guide medical management of rare childhood diseases.

Both whole exome and whole genome testing were conducted as part of this study. These tests search an individual’s genetic code for imperfections that are the source of disease.

“Trying new approaches to understand what these children have is important because it helps families when they have an answer about what it is that’s making their child so sick,” adds study co-author Geneviève Bernard, MD, MSc, FRCPc, pediatric neurologist at the Montreal Children’s Hospital of the McGill University Health Centre (MUHC) and a researcher with the Child Health and Human Development Program of the Research Institute of the MUHC.

Patient evaluation and testing for this study was conducted at Rady Children’s Hospital-San Diego, Montreal Children’s Hospital of the McGill University Health Centre and the National Research Center in Cairo. Medical research institutions in Amsterdam, Hong Kong, Qatar and Egypt also played a supporting role in confirming the biologic impact of the mutation in the VARS gene.

“For ultra-rare conditions such as this one, collaboration among multiple research institutions is crucial to confirm that changes identified in the genetic code may be common to multiple children with similar clinical symptoms,” said study co-author Jennifer Friedman, MD, neurologist at Rady Children’s Hospital and professor at UC San Diego School of Medicine.

“Such cooperation and patient matching plays a critical role in the identification of new genes and provision of diagnoses to geographically dispersed individuals with the same rare disorder,” Dr. Friedman said.

In future experiments, the researchers hope to test whether dietary supplementation with valine or gene therapy may help to restore the altered protein in the brain of these children.

Results of the study were published in the journal Nature Communications under the title “Biallelic mutations in valyl-tRNA synthetase gene VARS, are associated with a progressive neurodevelopmental epileptic encephalopathy.”  DOI: 10.1038/s41467-018-07067-3 https://www.nature.com/articles/s41467-018-07067-3

Rady Children’s Institute for Genomic Medicine Appoints New VP of Research

Dr. Charlotte A. Hobbs joins the executive leadership team

February 11, 2019—The Rady Children’s Institute for Genomic Medicine (RCIGM) is pleased to announce that physician-scientist Charlotte A. Hobbs, MD, PhD, has assumed the role of Vice President of Research and Clinical Management.

Dr. Hobbs brings a wealth of experience as a distinguished clinician, researcher, medical educator and hospital administrator. She has directed national studies of birth defects and pediatric health funded by NIH and CDC, among others. She recently completed a $6.1 million NIH-funded Genome Wide Association study involving more than 8,000 individuals in eight states.

“We are very pleased to have recruited Dr. Hobbs to join the Institute’s executive leadership,” said Stephen Kingsmore, MD, DSc, President and CEO of the Rady Children’s Institute for Genomic Medicine. “She brings deep expertise in building biomedical research programs and a passion for improving patient outcomes. That combination makes her uniquely qualified to join us in our mission to transform pediatric care.”

In her new role, Dr. Hobbs will guide the growing research and clinical programs at RCIGM. She will oversee the clinical genomics team, including physicians, nurses, genetic counselors and project managers, providing them with the intellectual and administrative infrastructure to support the Institute’s initiatives and goals.

Prior to joining the Institute in January of this year, Dr. Hobbs was Executive Associate Dean for Clinical and Translational Research at the University of Arkansas for Medical Sciences (UAMS) and Arkansas Children’s Hospital. In that role, she supported faculty scientists in their mission to develop biomedical knowledge leading to improved healthcare.

At UAMS she held a number of key leadership positions. Until her departure in December 2018, she was also Chief Research Information Officer. During 2016-2017, as a professor in the Department of Pediatrics, she fulfilled the role of director and co-principal investigator of the NIH-funded Data Coordinating and Operations Center for the 17-site Pediatric Clinical Trial Network in 2016-2017. Throughout her career, she continued her clinical service in neonatology attending in Level I to III nurseries.

“I am delighted to be part of the Institute’s pioneering team bringing precision genomic medicine to the cribs and bedsides of critically ill infants and children,” said Dr. Hobbs. “I finished pediatric residency 23 years ago, before the first human genome was sequenced. At that time, it was beyond my wildest imagination that someday I would have the opportunity to bring together my experience and skills in clinical medicine, informatics and genomics to join an extraordinary team combining science and medicine to improve the health of babies and children for generations to come.”

Dr. Hobbs is married to Jim Robbins, PhD, a native of Little Rock, AR and a health service researcher. They have three adult children between the ages of 21 to 23, who are currently in college.