Stem cells could cure hereditary deafness within 5 years


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By The Sun November 21, 2016

Scientists believe they are on the brink of a cure for people born deaf after producing stem cells to correct a hereditary defect.

Experts have found a way of growing new cells for the cochlea, the spiral cavity of the inner ear.

These can be used to replace faulty ones in people deaf from birth due to a genetic error.

They hope a treatment could be available to patients within five to 10 years.

Professor Kazusaku Kamiya, a specialist in ear diseases who is leading the research, said: “I am very excited by what we have done. We hope this work will lead to a cure for a form of hereditary deafness.

“We have found a way to make cochlear stem cells. The next step is to find a way to safely inject them into the patient’s ear.”

The work, which is being carried out in a laboratory at Juntendo University in Tokyo, Japan, aims to correct a mutation in a gene called Gap Junction Beta 2, which accounts for deafness or hearing loss for one in a thousand children.

In some parts of the world, mutations of this gene are responsible for as many as half the instances of congenital hearing loss.

Professor Kamiya and his team have engineered and grown stem cells to replace human cochlear cells without this mutation.

Stem cells can change into another type of more specialized cell through a process known as differentiation.

Hereditary hearing loss is often caused by a genetic mutation in the hair cells of the ear, which are found in the inner ear, or cochlea, and are the sensory receptors of sound.

Patients with this condition are currently treated with an artificial implant, which helps transfer sound to the patient’s hearing nerves.

Many scientists believe stem cells could offer a better solution by restoring the normal function of the hair cells and, as a result, the patient’s hearing.

Humans are born with about 11,000 hair cells in each ear that are vital to transmit sound. As the body ages, it experiences the slow progression of hearing loss due to the death of these cells from excessive noises, exposure to certain drugs, and ageing.

One approach could be to place stem cells surgically within the cochlea so they fuse with the remaining cells in the inner ear, and develop and function as normal non-faulty hair cells.

Currently there are no cures for most types of hearing loss.

The latest research into stem cells follows previous work led by Dr Marcelo Rivolta, from the University of Sheffield, who is also developing technologies to repopulate the deaf ear with vital hearing cells.

His colleague, Dr Sarah Boddy, has also been working on a project investigating the potential of human bone marrow stem cells as a way to reverse hearing loss.

The team has shown that human bone marrow stem cells can be converted into ear-like cells after exposure to a mixture of chemicals produced by foetal cochlear cells.

About a third of 65-year-olds say they are hearing impaired, a number that rises to half by age 75.