[Study of a familial insertional translocation involving chromosomes 1 and 7 by using fluorescence in situ hybridization].

OBJECTIVE

To determine the karyotype of a case with a history of spontaneous abortion and terminal deletion by using of conventional G-banding method and search the cause of insertional translocation of chromosomal terminal region.

METHODS

Fluorescence in situ hybridization (FISH) technique was performed to analyze the case by using whole chromosome 7 painting probe and subterminal probe of 7q36-->qter which was generated by chromosome microdissection technique.

RESULTS

The case was a carrier with a very rare insertional translocation involving chromosomes 1 and 7. The region of chromosome 7q36-->qter was not inserted into chromosome 1. The abnormal chromosome was inherited from her mother.

CONCLUSION

The present authors provided an experiment evidence that in this case the chromosome insertional translocation including the terminal region was still a three breakage rearrangement and the terminal deletion found by cytogenetics should be an interstitial deletion. Combining with chromosome microdissection, FISH technique is a powerful diagnostic method for detecting the chromosome structural abnormality.