Preimplantation Genetic Testing Services

PGT-A- 24-chromosome Aneuploidy Screening

During the first few days of embryo development, gain and/or loss of one or more chromosomes (called aneuploidy) is a common, natural phenomenon in embryos and can result in IVF failure and other poor reproductive outcomes. The use of PGT-A can identify the occurrence of aneuploidy and may be considered in all IVF cycles, with special benefit for couples at increased risk for chromosomal aneuploidy, including women who have had several miscarriages, failed IVF cycles, or who have had a prior pregnancy with a chromosomal abnormality. Women over 38 years of age and men with some types of sperm abnormalities may produce embryos with higher rates of chromosomal abnormalities including aneuploidy. By using PGT-A with your IVF cycle, only embryos with correct chromosomal number are used for transfer increasing the chances of a healthy pregnancy and reducing the risks for miscarriage. When embryos with normal screening results are transferred, the chances of a pregnancy are increased and the risks for miscarriage are reduced. PGT-A is performed using Illumina’s Next Generation Sequencing (NGS) system.

PGT-SR- Chromosome Structural Rearrangements

When a member of a couple carries a balanced translocation (exchange of chromosomal material between two or more chromosomes), a Robertsonian translocation (the joining of two chromosomes) or other chromosome structural rearrangements, their embryos are more likely to have an unbalanced chromosome complement. These abnormalities frequently cause birth defects, mental retardation, and/or miscarriage. PGT-SR for chromosome structural rearrangements identifies embryos for transfer that have normal or balanced chromosomal content. This allows couples to greatly increase the chance of a healthy pregnancy and to avoid prenatal complications. Please contact the laboratory to discuss the specific chromosomal rearrangement details before undertaking this type of PGT cycle. PGT-SR is performed using Illumina’s Next Generation Sequencing (NGS) system.

PGT-M: Monogenic Diseases

Inherited disorders such as Huntington disease, Spinal Muscular Atrophy (SMA), Cystic Fibrosis (CF), and fragile-X syndrome can be devastating to the families they affect. For couples that are at risk to have children with such diseases, Fairfax Diagnostics can provide PGD services specialized for that couple’s genetic situation. Due to the complexity of genetic testing for these disorders in IVF embryos, patients should have a full consultation with a medical geneticist to determine if this option would fit their family's needs. Prior to the PGD cycle, the laboratory must be notified in order to develop a patient-specific test for each disorder. In addition to testing for the presence or absence of the inherited disorder, aneuploidy screening is also performed and each embryo sample. PGT-M is performed using (1) mutation-specific targeted PCR and single-base sequencing, (2) allele haplotyping using linked STR, plus (3) Illumina’s Next Generation Sequencing (NGS) system for chromosome analysis.

All PGT approaches can provide gender information for each embryo and PGT-A is routinely used for gender selection and family balancing.