Related Experiment Video
Updated: Jun 27, 2026
Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss
Published on: January 25, 2016
Screening of the mitochondrial A1555G mutation in patients with sensorineural hearing loss
Luciano Pereira Maniglia1, Bruna Carolina Lemos Moreira2, Magali Aparecida Orate Menezes da Silva3
1Master's degree student, faculty member of the Otorhinolaryngology and Head & Neck Surgery Department, Medical School, S. J. Rio Preto, SP, FAMERP.
Unlabelled:
The A1555G mitochondrial mutation is the main alteration associated with aminoglycoside-induced deafness.
Aim:
to investigate the prevalence of the A1555G mutation in patients sensorineural hearing loss patients with and without aminoglycosides antibiotic use.
Material And Method:
a study of 27 cases with deafness as the sample, and 100 neonates with normal hearing as the control group. DNA was extracted from blood leukocyte samples, and specific oligonucleotide primers were designed to amplify the cytochrome b gene and the region which encloses the A1555G mutation of the mitocondrial DNA using the polymerase chain reaction and restriction fragment length polymorphism.
Design:
a cross-sectional case study.
Results:
a region of the cytochrome b gene was amplified and the presence of the mtDNA was confirmed in all of the 127 cases. The A1555G mutation was not found in any of the 27 patients with hearing loss or the control group with 100 neonates.
Conclusion:
the results agree with studies stating that the A1555G mutation is not prevalent in the Americas. There is interest in establishing the real prevalence of this mutation and to investigate other mutations that may cause hearing loss, associated or not with the use of aminoglycosides, in the Brazilian population.
Insights
The A1555G mitochondrial mutation, linked to aminoglycoside-induced deafness, was not found in Brazilian patients with sensorineural hearing loss or controls. Further research is needed to identify other causes of hearing loss in this population.
Area of Science:
- Genetics
- Otolaryngology
- Molecular Biology
Background:
- The A1555G mitochondrial mutation is a known cause of sensorineural hearing loss, particularly when exposed to aminoglycoside antibiotics.
- Understanding the prevalence of this mutation is crucial for diagnosing and preventing hearing loss.
Purpose of the Study:
- To determine the prevalence of the A1555G mitochondrial mutation in Brazilian patients with sensorineural hearing loss.
- To compare mutation frequency in patients with and without a history of aminoglycoside antibiotic use.
- To investigate potential genetic factors contributing to hearing loss in the Brazilian population.
Main Methods:
- A cross-sectional case study involving 27 patients with hearing loss and 100 healthy neonates as controls.
- DNA extraction from blood leukocytes.
- Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) to detect the A1555G mutation in the mitochondrial DNA (mtDNA) cytochrome b gene.
Main Results:
- The A1555G mutation was absent in all 27 hearing loss patients and 100 control neonates.
- Mitochondrial DNA was successfully amplified in all participants, confirming the presence of mtDNA.
Conclusions:
- The study findings suggest that the A1555G mutation is not prevalent in the studied Brazilian population.
- These results align with previous research indicating low prevalence in the Americas.
- Further investigation into other genetic mutations causing hearing loss, with or without aminoglycoside association, is warranted for the Brazilian population.
