Research from University College London (UCL) showed a genetic mutation affecting one in every 500 Caucasian babies leaves them open to permanent hearing loss if treated with the drugs.
Aminoglycoside antibiotics are used to control the life-threatening infection known as gram-negative sepsis, which leads to inflammation throughout the body.
The medicines are already known to impair hearing and kidney function, but further studies have shown even a small dose can lead to permanent hearing damage in children carrying the mutation.
John Stanley, chief executive of the charity Sparks which funded the study, said it was a 'major discovery' with 'very important implications' to babies, children and adults.
Lead authors Dr Maria Bitner-Glindzicz and Dr Shamima Rahman, wrote in the New England Journal of Medicine: 'We believe that it will be cost effective to genetically screen groups of patients who will almost certainly receive aminoglycoside antibiotics, to see if they carry the mutation, before administering the antibiotics. This will allow an alternative antibiotic to be given to anyone who has the mutation.'
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