Introduction:
Preimplantation genetic diagnosis (PGD) for numerical and structural chromosomal abnormalities is performed using the fluorescent in situ hybridization (FISH) technique or chromosomal microarrays (CMA) as an alternative to prenatal diagnosis.
Aim:
To establish a molecular diagnostic tool for microdeletion/duplication syndromes.
Materials&Methods:
The ability to carry out the FISH or CMA techniques in one cell is limited by the size of the FISH probe and the resolution of the CMA (10Mb). As a result, cases of deletions or insertions that are too small for detection by the FISH probe and below the detection threshold of the CMA can be detected by molecular PGD using PCR.
Results:
Here we describe 3 couples who underwent prenatal diagnosis in order to perform fetal CMA. All 3 couples underwent termination of pregnancy because of a pathogenic result. In the first couple the father was found to be a carrier of a1.5 Mb duplication in chromosome 1q21. In the second couple there was a duplication of 1.7 Mb in chromosome 15q13.2 that was inherited from the mother, and in the third there was a deletion of 711kb inherited from the father also in the region of 15q13.2.
First we confirmed that the duplications and deletions in these families resulted from an inappropriate alignment of the chromosomes. Secondly we succeeded in establishing a haplotype.
Conclusions:
It is feasible to perform molecular PGD for microdeletion/duplication syndromes.
