Objective: This study was conducted on a patient with ring-chromosome 13 syndrome and the results were presented and comparatively analyzed with reference to the related literature so as to detect the correlation between chromosome 13 band and the phenotype.
Methods: In this study the authors used G-banding, C-banding, N-banding, high-resolution banding, phenotype location analysis, and a comparative review of literature.
Results: It was found that karyotypes of the patient's parents are normal. The patient's karyotype is 45, XX, -13/46, XX, r(13)/46, XX, r(13;13)/47, XX, 2r(13) (p13q32.3). The typical syndrome of ring-chromosome 13 is related to the deletion of 13q34; the deletion of 13q32-13q32.2 is related to hand and foot abnormality, heart murmur, renal defect, skeletal abnormality and external genital abnormality; the deletion of 13q32.3-13q33 is related to micrognathia; 13q22-13q32 is related to atresia, and 13q13-q22 is related to anencephaly.
Conclusion: It is confirmed that a new breakage-reunion point of ring-chromosome is located at 13p13 and 13q32.3. The variety of clinical characteristics and phenotypes in patients with ring-chromosome 13 syndrome are closely related to the differences of the deletion of chromosome 13.