A feasible strategy of preimplantation genetic diagnosis for carriers with chromosomal translocation: Using blastocyst biopsy and array comparative genomic hybridization.
OBJECTIVE
Patients with chromosomal translocation are highly vulnerable to produce unbalanced gametes that result in recurrent miscarriages, affected offspring, or infertility. Preimplantation genetic diagnosis (PGD) with blastomere biopsy and fluorescent in-situ hybridization (FISH) has been used to select normal/balanced embryos for transfer. However, FISH is inherent with some technical difficulties such as cell fixation and signal reading. Here we introduce a strategy of PGD using blastocyst biopsy and array comparative genomic hybridization (aCGH) for reproductive problems of patients with chromosomal translocation.


METHODS
Twelve patients diagnosed as having chromosomal translocation who underwent PGD cycles were included in this single-center observational study. Blastocyst biopsy was performed and biopsied blastocysts were cryopreserved individually. Testing was performed with aCGH, and the euploid embryos were transferred in the following thawing cycles.


RESULTS
The overall diagnostic efficiency was 90.2% (55/61) and the euploidy rate was 32.7% (18/55). Ten cycles of thawed embryo transfer (ET) were carried out, resulting in three live births and another three ongoing pregnancies with an ongoing pregnancy rate of 60%/transfer cycle. The prenatal diagnosis with chorionic villi sampling confirmed the results of PGD/aCGH in all six pregnant women. No miscarriage happened in our case series.


CONCLUSIONS
Our study demonstrates an effective PGD strategy with promising outcomes. Blastocyst biopsy can retrieve more genetic material and may provide more reliable results, and aCGH offers not only detection of chromosomal translocation but also more comprehensive analysis of 24 chromosomes than traditional FISH. More cases are needed to verify our results and this strategy might be considered in general clinical practice.
Department of Obstetrics and Gynecology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.
Chu-Chun
CC
Huang
Li-Jung
LJ
Chang
Yi-Yi
YY
Tsai
Chia-Cheng
CC
Hung
Mei-Ya
MY
Fang
Yi-Ning
YN
Su
Hsin-Fu
HF
Chen
Shee-Uan
SU
Chen
D000328:Adult; D001706:Biopsy; D001755:Blastocyst / Q000473:pathology*; D055028:Comparative Genomic Hybridization / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006580:Genetic Carrier Screening / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods*; D014178:Translocation, Genetic
array comparative genomic hybridization (aCGH); blastocyst biopsy; chromosomal translocation; infertility; preimplantation genetic diagnosis (PGD)