The UC Davis Division of Genomic Medicine has received a two-year, $50,000 grant from the Children’s Miracle Network at UC Davis to bring next-generation genomic sequencing (NGS) to children in need in the Sacramento region. The grant will support NGS for children with undiagnosed, often congenital, conditions to find the underlying genetic causes and improve their care.
“Many public and private insurance carriers really view genomic sequencing as experimental so it’s not being covered,” said Katherine Rauen, chief of genomic medicine at UC Davis and principal investigator on the grant. “However, there is a lot of information in the literature that sequencing is not experimental anymore. We’re going to identify patients who would benefit from next-generation sequencing but, because their insurance doesn’t cover it, have no access.”
The UC Davis Genomic Medicine team believes NGS could provide medical answers for many undiagnosed patients. These children, and their families, often suffer for years while waiting for a diagnosis. Multiple tests can be inconclusive, hamstringing physicians, who cannot effectively treat a child’s disease without a definitive diagnosis.
NGS can help clinicians identify even the rarest conditions. Just having a diagnosis can help physicians manage a child’s disease, give patients access to clinical trials and provide critical answers for families, Rauen said.
The grant will help the UC Davis Division of Genomic Medicine expand its Precision Genomics Clinic, establishing a Clinical Genomics Review Committee to assess each case and determine the best path forward. The committee, which is being staffed by experts from multiple disciplines, will review the patient’s symptoms, previous test results, family history and other factors to determine which sequencing approach will be most helpful.
In some cases, the team will sequence a child’s exome, the ~19,000 genes that code for proteins. If other diagnostic tools have narrowed the possibilities, they may order a less comprehensive, targeted genetic test to assess one, a hundred genes or fewer. In some cases, if an exome sequence does not provide answers, the group may sequence a patient’s entire genome (3.3 billion nucleotides).
“It is a collective and iterative approach,” said Suma Shankar, associate professor of pediatrics and director of the Precision Genomics Clinic at UC Davis. “We may find hundreds, or even thousands, of variations in the genome, but the ability to identify the disease-causing pathogenic variant comes from narrowing the genes of interest and correlating the findings to the patient’s clinical presentation to make the final diagnosis.”
This stepped approach ensures the patient receives the most appropriate genomic tests while also managing scarce resources. In addition, sequencing has great potential to lower health care costs. Having the ability to rapidly diagnose patients reduces the needs for additional tests, helps guide clinicians to the correct therapies and can keep patients out of the hospital.
“There will probably be a day when patients with an underlying genetic etiology go straight to whole genome sequencing,” said Rauen. “Right now, patients go through this diagnostic odyssey – they get so many genetic tests that don’t get us to the right answer. All of a sudden, a $1,000 genome gives us the answer. Not only are we saving time, we’re also saving money, and most importantly, providing our patients with answers and potential therapies.”
Individuals or families interested in having an evaluation can visit the UC Davis Genomic Medicine website for details on how to be referred.