The Nadeau family turned to whole-genome sequencing to try to suss out the cause the hearing loss that of five of the 10 children had, the Boston Globe recounts. Jeanne and Andy Nadeau also wanted to know whether that loss would worsen as the children got older — the kids can hear some frequencies, but not all.
They started with other genetic tests, but they were not conclusive. Then with Heidi Rehm and her team at Partners Laboratory for Molecular Medicine, the family underwent sequencing. One of the first passes at analyzing their sequences turned up 31 changes affecting hearing-linked genes, but none seemed likely to be behind the problem, according to the Boston Globe.
A separate analysis, though, indicated that the affected children had two copies of a large deletion, and that was the likely cause of their hearing loss. Rehm's team has added the deletion to their hearing loss tests.
"The Nadeaus value the information they've gotten; they're hopeful that they will continue to learn more," the Globe writes. "But the question that drove them to testing in the first place remains unanswered; they still do not know whether their children will eventually become deaf."