Embryos of couples carrying chromosomal structural rearrangements (resiprocal translocation, Robertsonian translocation or inversion) might be abnormal and infertility/subfertility problems might be observed in some cases. In these cases, selection of balanced/normal embryos is possible with PGT-SR using FISH or NGS technology depending on the karyotype of the couple.
In balanced chromosomal rearrangement carriers PGT with NGS not only detects unbalanced chromosomal rearrangements due to chromosomes involved in translocation, but also detects other chromosomal aneuploidies.
In preimplantation genetic test of segmental aneuploidies, NGS technology can theoritically detect 10 mb partial deletions and duplications. Using patient tailored bioinformatic algorithms, enriched amplification and deep reading we can detect translocations as small as 2 mb.
As shown in the diagram below, while the small breakage region in chromosome 4 could not be detected using standard bioinformatics evaluation, it could be detected using adjusted algorithms during analysis.
As shown in the diagram below, while the small breakage region in chromosome 4 could not be detected using standard bioinformatics evaluation, it could be detected using adjusted algorithms during analysis.
