By Jeff Green

A PhD researcher in the Faculty of Medicine has discovered a gene mutation that is linked to significant hearing loss in young children in Newfoundland and Labrador.

The mutation is in a gene known as CLDN14.

One per cent

“Although this mutation has been identified in The Netherlands, Iceland and Denmark, this is the first time it has been shown to cause early onset hearing loss,” said Justin Pater, who is completing his degree under the supervision of Dr. Terry-Lynn Young in the Discipline of Genetics.

“What’s interesting is that the mutation is more common in this province, being present in just over one per cent of the population.”

Critical health care research

Mr. Pater is collaborating with a team of geneticists and clinicians at the Centre for Genomics-Based Research and Development in Hearing Science in Grand Falls-Windsor, which was established in April of this year. Their research was recently published in the academic journal Human Genetics.

Around the world, other mutations in the CLDN14 gene have been identified. Those studies have emphasized affected children who are born with hearing loss.

However, the research led by the Memorial team indicates something different, providing health-care professionals with critical information.

“With this hearing loss mutation, we found that children are actually born with normal hearing and pass newborn screening tests,” explained Mr. Pater, who is originally from Montague, Prince Edward Island.

“Children with our CLDN14 mutation develop hearing loss by three to four years of age, which is an important time for language learning. Our audiologist, Anne Griffin, will be helping to translate this new knowledge into the clinical setting to identify at-risk children and thereby prevent speech-language and developmental delay.”

Profound hearing loss

The CLDN14 gene produces a protein that plays an essential role in maintaining inner ear cell structure and the transmission of auditory signals to the brain.

When CLDN14 is mutated, sounds are not conveyed properly. People who test positive for the mutation have profound hearing loss at middle and high frequencies, while the perception of low frequency sound is preserved.

Research first

Mr. Pater and his collaborators are based at the Craig L. Dobbin Genetics Research Centre at Memorial, which opened in May 2015. Having their research published in a leading academic journal is a major accomplishment for the team.

“I am proud to be a part of a larger team that came together to discover this mutation,” said Mr. Pater. “Additionally, this publication was the first to come out of the Craig L. Dobbin Genetics Research Centre, where all genomic data was generated in-house and not outsourced to other institutions.”

‘Big impact’ research

Mr. Pater says he’s always been interested in genetics research.

Once he completes his PhD, he’d like to focus on cancer genetics and personalized medicine while continuing hearing loss research.

“Hearing loss is one of the most common medical conditions,” Mr. Pater noted. “Approximately 10 per cent of Canadian adults are affected by hearing loss and 50 per cent of these cases are caused by genetic mutations. It is these overwhelming statistics that drew me into hearing loss research. Not only can these discoveries have a big impact right here in Newfoundland and Labrador, but so, too, can they be extended to the national and international level.”