In many cases, the genetic analysis led to groundbreaking discoveries. Researchers discovered 11 new disease genes linked to developmental delays, and described new physical traits and symptoms for a number of known diseases.
The investigators recruited 41 children who were suffering from these delays, which could range from delayed walking and talking, to more severe problems like epilepsy or autism, explained senior researcher Dr. Clara van Karnebeek, pediatrician and biochemical geneticist at BC Children’s Hospital and principal investigator with the Center for Molecular Medicine and Therapeutics at the University of British Columbia.
Using traditional urine and blood tests, the researchers screened the children for 90 known metabolic diseases tied to developmental delay, and found that based on those tests, the children didn’t qualify for any of the known illnesses.
The researchers then performed an analysis of the children’s exome, the part of their genetic structure that guides the creation of proteins essential for the body to function properly.
Thanks to the genetic results, researchers were able to help 17 of the 41 children with treatments aimed directly at their genetic condition, she said.
“One of the parents explained the difference she saw in her son before and after,” van Karnebeek said. “Before, he was head-banging thousands of times a day, injuring himself. Afterwards, he calmed down. He was able to come home and have dinner with the family and watch TV.”
Many large medical centers and commercial labs are able to conduct these sorts of analyses for children with previously undiagnosed developmental problems, she said.
However, the genetic screen is expensive at this time, costing a couple of thousand dollars, on average, van Karnebeek added.
Dr. Edward McCabe, chief medical officer for the March of Dimes, called the study an “impressive investigation.”
“As sequencing gets cheaper, it’s the way we need to go to identify the cause of disorders in these patients,” McCabe said.