Revolutionising genetic diagnosis
Professor Bitner-Glindzicz’s clinical work focussed on helping families to understand the genetic cause of their hearing loss. In 1999 she established the first UK Genetic Deafness Clinic that has now become part of the NHS Genetic Service.
Over 100 genes have been identified that can cause inherited childhood deafness. Until relatively recently it was only possible to test one or two of the more common genes in the clinic – it would have been just too expensive and taken too long to routinely test any more. Professor Bitner-Glindzicz recognised the urgent need to develop faster and cheaper ways of testing deafness genes.
In a collaboration with Professor Van Camp at the University of Antwerp, and with funding from Action on Hearing Loss, she helped develop a new genetic test for hearing loss using ‘massive parallel sequencing’ technology. This allows a large number of genes (~95 deafness genes) to be simultaneously analysed at a fraction of the cost. This has been a real revolution in genetic testing that has greatly increased the chance that the specific gene responsible for an individual’s hearing loss can be identified and an accurate diagnosis made.
Getting an accurate diagnosis is important for many reasons. It can sometimes indicate if other health problems are likely to emerge, such as sight loss if diagnosed with Usher syndrome, or how the hearing loss might change over time. For some people, they just want to know why they have a hearing loss. In the future, as new therapies emerge to treat hearing loss, it will be really important to know the precise cause, so that the right treatment can be given to the right person. Getting an accurate diagnosis will also be the first step in designing personalised treatments targeting the specific genetic fault.
Exploring the link between genetics and ototoxicity in children
The prevalence of hearing loss in children born prematurely is estimated to be up to 10 times higher than in the normal childhood population. There are many factors that can cause childhood deafness. One of them is exposure to certain life-saving medicines that can damage the tiny hair cells in the cochlea that detect sound.
One such medicine is a specific class of antibiotic called aminoglycosides. They are often used as a first-line antibiotic in newborn babies and may be one of the reasons for the increased prevalence of hearing loss in premature babies. Interestingly, a mutation in a specific gene is known to exacerbate aminoglycoside-induced hearing loss. About 1 in 500 people in the population carries this genetic variant. We funded Professor Bitner-Glindzicz to better understand its contribution to hearing loss in premature babies – the findings could have important implications for setting policy around screening for this gene to identify babies at risk.
A true champion of hearing research
Professor Bitner-Glindzicz also made important contributions to research into Usher Syndrome and Norrie Disease, both genetic conditions that cause deaf-blindness. She was also one of the first clinicians to become involved in the 100,000 Genomes Project, a major project announced by David Cameron to sequence the genome of 100,000 NHS patients to identify the genetic causes of many diseases.
All at Action on Hearing Loss were shocked and saddened by the tragic death of Professor Maria Bitner-Glindzicz. She was a wonderful person, outstanding clinical geneticist and true champion of research into hearing loss and deafness, whose work transformed the lives of many.