PTPRM and coloboma of eyelid: The results of a selective sweep analysis of the upper eyelid coloboma trait in Huoyan geese showed that the high peaks in FST values were mainly found in chromosomes 12 and 23, and this fact is consistent with the genetic analysis that showed the upper eyelid coloboma trait is a sex-linkage inheritance [2].The candidate gene obtained on chromosome 12 is PTPRM, which is a member of the protein tyrosine phosphatase (PTPs) family.