A new study adds to research showing that genomic sequencing can provide useful information to guide diagnosis and personalized treatment of neurodevelopmental disorders including different subtypes of autism.
The researchers conclude that the benefits of genomic sequencing outweigh the costs and should become a routine part of evaluating children suspected of having a neurodevelopmental disorder.
“We’ve shown that genomic sequencing can often end the diagnostic odyssey and have an immediate impact on patient care,” says lead author Sarah Soden. Dr. Soden is a developmental pediatrician with the Center for Pediatric Genomic Medicine at Kansas City’s Children’s Mercy Hospital.
“Now we’re hopeful that we can show that the most powerful use of this technology will be in improving the course of development by enabling earlier diagnosis and treatment,” she adds.
Dr. Soden and her colleagues performed genomic sequencing on 119 children with neurodevelopmental disorders that included autism. Such sequencing goes far beyond conventional genetic testing, which scans a predefined set of genes already associated with a disorder.
Before enrolling in the study, the children (average age 7) had already undergone exhaustive but largely unsuccessful testing to identify the cause of their symptoms. The authors calculated the average cost of previous diagnostic testing totaled $19,100 per child.
Changed diagnoses and treatment plans
Their genomic sequencing identified a genetic cause and clear diagnosis in 53 children. More importantly, perhaps, the sequencing resulted in changed treatment plans for half the 119 participants. It led to new medicines or diets in some and the discontinuation of unnecessary treatments in others.
"This study provides a first glimpse into the health and economic impact of genome sequencing in neurodevelopment disorders, and I look forward to other studies to further explore these interesting findings,” comments Stephen Scherer, director of Autism Speaks whole genome sequencing program. Dr. Scherer was not directly involved in the new study. Last year, he led the first sizable study to use genomic sequencing to investigate autism. That study focused on 32 families affected by autism. It identified associated gene changes in half of the participants and provided medical guidance for several families.
Deciphering an unusual case of severe autism
Among the participants in her study, Dr. Soden described one of her own patients – a boy with an unusually severe form of regressive autism. At 6 months, he began having seizures that did not respond to anti-epilepsy drugs. At 1.5 years, he developed repetitive behaviors and became withdrawn. This led to his autism diagnosis. However, the boy’s symptoms continued to worsen. By age 3, he was having up to 30 seizures a day. Eventually his motor difficulties led to wheelchair use.
At age 10, the boy enrolled in Dr. Soden’s study. Genomic sequencing uncovered a change in a gene called PIGA. Previous research had shown that a similar change in this gene blocked production of vital proteins – producing seizures that could sometimes be eased with the vitamin supplement pyridoxine.
Unfortunately, pyridoxine did not work for this boy. “It may have been that his particular genetic change wasn’t one that would respond to pyridoxine,” Dr. Soden says. “However it’s also possible that he would have responded if we’d intervened earlier – before his condition had progressed so far.”
Earlier diagnosis from routine use of genomic sequencing could potentially jumpstart such treatments for developmental disorders years earlier, Dr. Soden and her colleagues conclude. They are planning a study with infants to pursue this idea.
In related comments, Dr. Soden expressed special appreciation for Autism Speaks and its fellowship opportunities, noting that her own career in autism research was launched by a fellowship grant from Cure Autism Now, which merged with Autism Speaks in 2007. Learn more about Autism Speaks pre- and post-doctoral fellowship programs here and here.
For more on the promise of whole genome sequencing in diagnosing and treating autism subtypes, see MSSNG: Changing the future of autism with open science. An unprecedented collaboration between Autism Speaks and Google, MSSNG involves the analysis of 10,000 anonymous genomes from families affected by autism, with the goal of making them freely available for global research.