[Combined use of molecular cytogenetic techniques to detect a small chromosomal translocation].

OBJECTIVE: Comprehensive use of molecular cytogenetic techniques for the detection of 1 case of small chromosome translocation. METHODS: Following conventional chromosome preparation, G-banding karyotype analysis, spectral karyotyping (SKY), whole chromosome painting, two-color fluorescence in situ hybridization (FISH) and subtelomeric probe FISH were performed. RESULTS: G-banded karyotype was 46, XX, ?(22q11.3), SKY karyotype analysis was 46, XX, der (4)t(4;6) and found no abnormalities on chromosome 22, staining signal was not found with any abnormalities on chromosome 6. Two-color FISH indicated a chromosomal translocation segment of 22q13.3 to one end of the short arm of chromosome 4. Subtelomeric FISH probe showed the end of the long arm of chromosome 22 and the end of the short arm of chromosome 4 reciprocal translocation. High resolution G-banding and FISH result indicated 46, XX, t(4;22)(p15.3;q13.2). CONCLUSION: The testing of small chromosomal translocation should be combined with clinical information and integrated use of molecular cytogenetic techniques to improve the accuracy of diagnosis of chromosomal diseases.