Analysis of Blastomere or Blastocyst from Carriers of Pericentric Inversion of Chromosome 9 with the Use of FISH and Array Comparative Genomic Hybridization

OBJECTIVE: To evaluate the value of fluorescence in situ hybridization (FISH)-based or array comparative genomic hybridization (aCGH)-based preimplantation genetic testing for chromosomal structural rear-rangements (PGT-SR) for patients carrying pericentric inversion of chromosome 9 (inv[9]). STUDY DESIGN: We used FISH and aCGH to analyze the frequency of chromosomal 9 abnormalities in blastomere or blastocyst samples obtained from 273 couples carrying inv(9). RESULTS: Of the 1,010 blastomere samples tested by FISH, 451 (44.7%) had chromosome 9 abnormalities. The incidence of abnormalities did not differ significantly among women of different ages. A definite diagnosis was obtained for 230 embryos at the blastocyst stage by aCGH, but only 1 had chromosome 9 abnormality, while 87 had abnormalities in other chromosomes. The rate of chromosome abnormalities was higher in women >35 years of age. Twenty embryos classified as abnormal by FISH were reanalyzed at the blastocyst stage by aCGH, but none had chromosome 9-related abnormalities, and 9 (45%) had abnormalities in other chromosomes. CONCLUSION: In conclusion, our study findings indicate that pericentric inversion of chromosome 9 should not be considered as the indication of PGT-SR. Blastocyst biopsy with comprehensive chromosome screening technologies are more suitable than cleavage stage biopsy and FISH for inv(9) carriers with advancing years or a negative reproductive history.