Objective: To search for the possible relation between tortilcollis and partial chromosome 13q trisomy.
Methods: Fluorescence in situ hybridization (FISH) technique combined with chromosome banding was performed to determine the karyotype of two patients with typical clinical features of partial 13q trisomy syndrome, then their manifestations were compared with those of the literatures published previously.
Results: The two cases were partial trisomy of 13q14--> ter with a different second derivative chromosome, in spite of this difference, both of them had tortilcollis.
Conclusion: It is suggested that a potential site for tortilcollis may locate on the long arm of chromosome 13. With reference to a report previously published, the more precise candidate related region may be 13q32--> qter.