Scientists in the Netherlands have discovered a new gene linked to the type of inherited deafness passed on through families.
Around half of all cases of deafness are thought to be inherited and experts have so far painstakingly pinpointed around a third of the 60 genes involved.
The latest find means knowledge about the gene could be incorporated into standard genetic testing, meaning experts will be able to tell families with hereditary deafness their likelihood of having a child who is deaf, and also bring possible treatments one step closer.
Every year in the UK 840 babies are born with significant deafness, and one in 1,000 children are deaf at the age of three. A further 20,000 children up to the age of 15 are moderately to profoundly deaf.
The latest research was funded by the Royal National Institute for Deaf People (RNID) and published in the American Journal of Human Genetics.
Scientists looked at the genetics of families where several members were deaf and identified the PTPRQ gene as playing a role, the third such discovery by the same team in the last few months.
RNID chief scientific adviser Dr Sohaila Rastan said: "This research will help develop medicines that are desperately needed to prevent deafness and restore hearing."