18-month-old Opal Sandy becomes youngest to regain hearing via gene therapy trial by Regeneron.

The therapy corrects a rare genetic mutation linked to hereditary deafness, with Opal's hearing near normal.

A working copy of the OTOF gene is delivered to patients to rectify auditory neuropathy.

This medical advancement signals a new chapter in treating genetic hearing impairments.

The ongoing trial spans the UK, Spain, and the US, aiming to potentially cure genetic deafness in up to 18 children.

Opal's case sparks hope for future treatments that could benefit a wider population with similar conditions.

Adapting to Opal's recovery, her parents now embrace her eagerness to explore sounds.