Objective: To investigate whether LHX1 gene mutations exist in Han Chinese patients with müllerian duct abnormalities (MDAs). Design: Mutation screening. Setting: University hospital. Patient(s): Ninety-six MDA patients and 105 control subjects from a Han Chinese population. The parents of the patients carrying the genetic variation were also screened. Intervention(s): Gene sequencing. Main Outcome Measure(s): Karyotype, LHX1 gene sequencing. Result(s): We found no significant mutation in coding regions of LHX1. However, there is a new rare polymorphism of LHX1 gene, c.1070–1081del, found in 1 out of 77 incomplete müllerian fusion patients and 1 out of 105 control individuals in the Han Chinese population (thus affecting ∼1% of Han Chinese). Conclusion(s): No causative perturbation was identified in the LHX1 gene. Mutations in the coding regions of LHX1 may not be a common genetic etiologic factor involved in Han Chinese MDA patients. [ABSTRACT FROM AUTHOR]