P37 Routine use of PCR for PGD in translocation carriers: New developments to differentiate balanced carriers from non-carriers

Abstract

at KFSHRC in order to increase the confidence of the diagnosis and to test for diseases with unidentified mutations. Materials and Methods: Couples were counseled and consented. WGA from single blastomeres was achieved using multiple displacement amplification (MDA) followed by disease specific mutation detection and/or PGH. Results: Fifty cycles were performed for 31 couples at risk of autosomal recessive or dominant, or X-linked disorders. A total of 328 embryos were tested, 301 of the samples were successfully amplified by MDA with an amplification efficiency of 92%. From the MDA product, 1462 PCR reaction were set and 47 (3.2%) amplification failure were observed. Allele drop out (ADO) were observed in 101 alleles (3.5%). The confirmations of PGH results with the mutation testing were available for 269 embryos. Of those, 239 (89%) showed full concordance. There was a discrepancy between the PGH and mutation analysis from 12 embryos (4.5%). From the remaining, 4.5% were though concordant; PGH results showed a haploid pattern indicating that such embryos are being haploid or monosomic for that specific chromosome. Consequently, such embryos were not considered for transfer. There were 6 (2%) embryos on which diagnosis could not be predicted either due to maternal cell contamination or extensive ADO with PGH analysis. For the cycles only PGH were performed either due to unknown mutation or gene expansion, there were 8 cycles for 4 couples. A total of 56 embryos were tested by PGH analysis and 53 (95%) give conclusive results to make a clear diagnosis. Of the 50 cycles, 42 had embryo transfers resulting 15 pregnancies (35.7%) in 13 couples. One of the pregnancies resulted in abortion while the remaining is either ongoing or delivered. Conclusions: PGH helps to confirm the diagnosis and increase the confidence, as it predicts the origin of inheritance of each chromosome. It can also be safely used to make diagnosis in the absence of known mutation.