Plain English Summary
Background and study aims
Acquired hearing loss is a hearing loss that appears after birth. It occurs ten times more often in infants born before 32 weeks of gestation (very preterm). There are several possible causes, including the side effects of some regularly used medications on neonatal units, such as aminoglycosides. These are known to have effects on the hearing system but, despite being at high risk of receiving aminoglycosides, there is little evidence for drug-induced damage to the inner ear in preterm children. The risk of hearing loss may be increased further in babies with the DNA mutation m.1555A>G. Patients with this mutation who receive aminoglycosides suffer from hearing loss even when drug levels are maintained within normal limits; this effect may be reduced in the newborn period, but this has not been formally studied. The aim of this study is to look at the relationship between the m.1555A>G mutation, aminoglycosides and deafness in children born very prematurely.
Who can participate?
Deaf children and children with normal hearing who were born at 31 weeks and 6 days of gestation or less
What does the study involve?
Saliva samples are taken from children in both groups for genetic analysis of m.1555A>G. Clinical data including information on aminoglycoside exposure is taken from medical notes.
What are the possible benefits and risks of participating?
The main benefit to participants with deafness is the opportunity to find the cause of their hearing loss. If the child has the mutation, it is likely that this is the cause. There is little benefit for participants who have normal hearing, but if they test positive for the mutation they are advised to avoid aminoglycoside antibiotics in the future to prevent the risk of hearing loss. There are no anticipated risks for participants, although children could be nervous about having a saliva sample taken.
Where is the study run from?
University College London (UK)
When is the study starting and how long is it expected to run for?
January 2013 to January 2016
Who is funding the study?
Action on Hearing Loss (UK)
Who is the main contact?
1. Prof. Maria Bitner-Glindzicz (email@example.com)
2. Prof. Neil Marlow (firstname.lastname@example.org)
Prof Maria Bitner-Glindzicz
30 Guilford Street
Gentamicin, genetic variation and deafness in preterm children: a case-control study
The hypothesis is that mutation (m.1555A>G) makes a significant contribution to deafness in babies born at 31 weeks and 6 days of gestation or less who receive treatment with aminoglycosides, even when drug levels were within the normal range.
NRES Ethics Committee London - Central, 02/02/2012, ref: 12/LO/0005
Primary study design
Secondary study design
Patient information sheet
Hearing loss in preterm infants
This is an observational study which will only involve saliva samples and access to medical notes. Children with hearing loss will be invited to participate by their audiological paediatrician; ex-preterm children with normal hearing will be invited by their neonatologist. Saliva samples will be taken from children in both groups for genetic analysis of m.1555A>G. Clinical data including information on aminoglycoside exposure will be abstracted from medical notes.
Primary outcome measures
Prevalence of the m.1555A>G mutation, measured using saliva samples tested for the mutation by direct DNA sequencing
Secondary outcome measures
Gentamicin administration, measured using data from medical notes
Overall trial start date
Overall trial end date
Participant inclusion criteria
Cases: babies born at 31 weeks and 6 days gestational age or less with hearing loss, treated on a neonatal unit within Greater London between 01/01/2009 - 31/12/2013
Controls: babies born at 31 weeks and 6 days gestational age or less with normal hearing, treated on a neonatal unit within Greater London between 01/01/2009 - 31/12/2013
Target number of participants
30 - 60 deaf children and 5 controls per deaf baby/child. Total 150-300 children
Participant exclusion criteria
Cases: no exclusion criteria
Controls: missing data in medication records
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University College London - Institute of Child Health
Action on Hearing Loss (UK) (ref: RNID G47)
Funding Body Type
private sector organisation
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The trialists intend to publish in 2017.
IPD sharing plan
The current data sharing plans for the current study are unknown and will be made available at a later date.
Intention to publish date
Participant level data
To be made available at a later date
Results - basic reporting