AIM: To study the KIF21A gene mutation in a Han family with concomitant exotropia.

METHODS: The genomic DNA of five family members was extracted from peripheral blood leukocytes and amplified with PCR. The PCR products were purified for DNA sequencing. DNA sequences were aligned with the human KIF21A gene sequences registered in GenBank.

RESULTS:Mutation analysis of all exons of the pedigree's KIF21A gene reveals no gene mutation in any of the families.

CONCLUSION: Our study demonstrates that the KIF21A gene maybe is not virulence gene in this pedigree.