Genetics of Hearing Impairment in North-Eastern Romania—A Cost-Effective Improved Diagnosis and Literature Review

Round 1

Reviewer 1 Report

This manuscript provide a small insight in the prevalence of NSHI in a clinical sub-population of Romania. Despite the soundness of the aim there are several concerns:

Introduction : is well described but the aim should not be addressed as a general investigation of the genetic causes (it is impossibile without a control group in such small sample). It should  be more orientated to define a preliminary exploration of the prevalence of genetic abnormalities in hearing loss subjects. 

Please implement several limitations :

• poor audiometric testing (there is no exclusion of conductive hearing loss or middle ear diaseses) 
• the sample is too small to assess any inference  
• there is the lack of control group

Despite that the manuscript is well written and has a good style. It is very interesting the abnormalities found in the Roma sub groups and it worth for further studies.  

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

No comment

Author Response

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Reviewer 3 Report

Genetics of hearing impairment in North-Eastern 2 Romania - a cost-effective improved diagnosis and literature review

This study by Resmerita et al. investigates the main genetic causes for NSHI in the North-Eastern region of Romania and proposes a cost-effective diagnosis protocol for developing countries. In this study, they used MLPA followed by Sanger Sequencing for 291 patients. They identified two variants: c.109G>A and c.100A>T that have not been reported in any study from Romania and conclude that MLPA is an inexpensive, rapid and reliable technique that could be a cost-effective diagnosis method, useful for every patient with hearing impairment. It can be adaptable for the mutation spectrum in every population and followed by Sanger sequencing can provide a genetic diagnosis for patients with different degrees of hearing impairment.

1. More detailed information about how the previous literature has been done should be included in the introduction part. For example, is Multiplex Ligation-dependent Probe Amplification (MLPA) first used as a genetic test tool? If not, how has it been used in Romania or other countries? In line 63, this sentence looks weird here.
2. In line 81, “Hearing levels were measured by pure tone audiometry, which included bone conduction.” However, the age range in this study is from 1 month old. So, the hearing levels were got several years later? More details should be given here.
3. In line 135,” Mutations in GJB2, GJB3, GJB6, POU3F4, and WFS1 genes were analyzed by MLPA that revealed abnormal results in 141 cases (48.45%).” With MLPA, four types of genes were screened. However, only GJB2 and WFS1 genes mutation were described. How about the other three genes?
4. In line 136,” 4 (2.84%) had variants in WFS1 gene”. I cannot find more information about these 4 WFS1 mutations. The authors need to indicate all the results from the genetic testing clearly.
5. Some of the sentences are too long and hard to follow—for example, the sentence in line 168.
6. As the second purpose of this study is to find a cost-effective diagnosis protocol. However, it lacks evidence that MPLA could be a more cost-effective protocol in gene screening. More information should be added in the discussion part. A table should be added to describe it.
7. Some of the sentences should be reorganized. For example, in line 188,” GJB2 being responsible….”; in line 204, too many commas in the sentence. In line 233, “we did not include in our study normal hearing individuals.”
8. In line 224-225, the author mentioned that the diagnosis age of c.101T>C was older than c.35delG.
9. In line 278, the author stated that patients with c.109G>A had progressive bilateral and profound to severe hearing impairment. So, all these three patients showed the same pattern of hearing loss?

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have significantly improved the manuscript, and it is now acceptable for publication.