Review for 10.1186/s12876-016-0509-1 (2016)

Reviewer ’s report  
 
Title: Male -specific association between MT -ND4 11719 A/G polymorphism and ulcerative 
colitis: a mitochondria -wide genetic association study  
 
 
Version: 0 Date: 16 May 2016  
 
 
Reviewer: Ka kei  Wu 
 
Reviewer's report:  
 
In this work, Dankowski and colleagues analy zed genotyping results of German ulcerative colitis 
(UC) cases (n=1062) and German healthy controls (n=3030) and identified a genetic association 
between the MT -ND4 11719 A/G polymorphism and UC. This association was successfully 
replicated in the second i ndependent cohort (1625 UC cases and 3575 controls). For the first 
time, an association between the mitochondrial SNP ND4 11719 A/G and UC was identified. 
The results are novel and will improve our understanding of the genetic basis of UC.  
 
Minor comment:  
The authors should discuss their findings in relation to a recent paper by Rosa and colleagues 
(Inflamm Bowel Dis. 2016 Apr;22(4):774 -81.), who identified a novel association between 
A10550G in MT -ND4L and UC.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in th e manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further  
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of wri tten English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please compl ete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from 
an organisation that may in any way gain or lose financially from the publication of th is 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applyi ng for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have no competing interests' 
below.  If your reply is y es to any, please give details below.  
 
'I declare that I have no competing interests'  
 
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