Review for 10.1186/s12876-018-0925-5 (2019)

Reviewer ’s report  
 
Title:  Mitochondrial neurogastrointestinal encephalopathy as a mimic o f Crohn's disease: a case 
report  
 
Version: 2 Date: 06 Nov 2018 
 
Reviewer:  Holm  Uhlig  
 
Reviewer’s report:  
 
This is short and concise presentation of 2 patients with Crohn's disease and  Mitochondrial 
neurogastrointestinal encephalopathy (MNGIE) an autosomal recessive disorder.  
 
The report is well written and informative since it affects the diagnosis of Crohn's disease in a 
rare Mendelian disorder and potentially the response to azathioprin. It adds to the curretn 
literature in particular Garone et al.  Brain. 2011.  
 
In addition to the case report, that authors searched the UK  IBD Genetics Consortium dataset of 
2513 patients with Crohn's disease for MNGIE variants.  
 
This is an important strategy but the authors need to provide a proper analysis since the 
sequencing performed in the Luo et al. Nat Genetics 2017 paper was not desi gned to detect 
ultrarare variants - what is the coverage of the gene sequencing in this region? What is the power 
to detect one heterozygous mutation with the available coverage and the call algorithm used? 
What is the power to detect two heterozygous muta tions? Is this sufficient to exclude variants?  
 
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 the 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 recommend additional statistical review  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete 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 this 
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3. Do you hold or are you currently applying 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 yes to any, please give details below.  
 
I declare that I have no competing interests  
 
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