Q: What is the reference style followed by BMC Medical Genetics?
I want to submit to BMC Medical Genetics, but after checking their submission guideline, I didn't find any reference instructions. What should I do?
You can find reference instructions under each article type in the submission guidelines of BMC Medical Genetics. For a research article, the detailed reference instructions can be accessed here:
Read the subsections titled "References" and "How to format your references."
According to these instructions, in-text citations should be numbered and should be placed within square brackets immediately after the quote or reference to the source in your article: 
The reference list should be placed at the end of the article. All references must be numbered in the order in which they appear in the text, and should be written in the following format:
1. Author Surname A: Article Title. Publication Title. Year Published, Volume number(Issue number):Pages Used.
1. Happell, B. Responding to reviewers’ comments as part of writing for publication. Nurse Researcher. 2011:18(4): 23-27.
You could also check any of the featured articles on the journal homepage to get a clearer idea of the reference and citation style to be followed.