Pre-Implantation Genetic Diagnosis Now Available to all Canadians!

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Submitted by D Lewis.

Until recently, Pre-Implantation Genetic Diagnosis (PGD) has been available to a limited number of Canadian couples.

Through PGD, embryos affected by single gene defects, x-linked disorders and chromosome translocation can be identified so that only unaffected embryos are transferred to the uterus. PGD is recommended for couples who have suffered multiple, unexplained miscarriages, those who already have an affected child and those who are aware of the existence of an inherited genetic disorder in either partners’ family.

Perhaps owing to the prohibitive costs of the specialized equipment and the shortage of trained personnel in Canada, the PGD lab at the McGill Reproductive Centre (MRC) in Montreal is the only one of its kind in Canada. In 1997, Dr. Asangla Ao, Senior Scientific Officer from Hammersmith Hospital in London was recruited as Scientific Director for the McGill PGD program. Over the next few years, Dr. Ao assembled and trained a scientific team to perform PGD and related research.

Patients were previously required to travel to Montreal for their IVF treatment or have the analysis done by laboratories located in the United States. Owing to U.S. Customs restrictions on the shipment of human tissues/cells into the U.S., as many as half of these samples were refused at the border. The cost of these services in U.S dollars was another disadvantage to the Canadian patient.

This treatment is now available to all Canadians through the newly launched Transport PGD program. The MRC has made IVF available to Canadian couples in remote areas through the Transport IVF program. Dr. Seang Lin Tan, Director of the McGill Reproductive Centre worked with a team of engineers to design an incubator suitable for the transport and protection of eggs, sperm and embryos. In the Transport IVF program, these samples were transported between the patients’ local hospital and the MRC.

An improved incubator has now been designed for use with the new Transport PGD program which now offers three possible options:

i) The embryos can be created at the patients’ local IVF Centre, and then flown to Montreal at the one cell (2PN) stage. The embryos are cultured at the MRC until day 3 of development when the biopsy is performed. After biopsy the entire cohort of embryos is returned to the referring IVF Centre. The results of the genetic analysis are transmitted to the referring IVF Centre to enable the embryologist to select suitable embryos for transfer to the patient.

ii) IVF Centres who have the equipment and trained staff to perform the embryo biopsy, can perform the biopsy at the referring Centre and the biopsied blastomeres are transported to the MRC. The MRC staff performs the genetic analysis and transmits the results back to the referring Centre.

iii) PGD is made available even when the referring IVF Centre does not have expertise in performing embryo biopsy and cell processing. An embryologist from the MRC travels to the referring centre. He/she performs the biopsy and processes the cell for genetic analysis. He/she returns to the MRC where the genetic analysis will be performed. Once the result is obtained, the data is returned to the referring IVF Centre.

Diagnoses now available:

Aneuploidy Screening

Robertsonian translocations

Some reciprocal translocations

Sexing (for medical reasons)

Single Gene defects

Cystic fibrosis (delta F 508, C551G, G553T)

Spinal muscular atrophy

Myotonic dystrophy (Steinerts)

Fragile X syndrome

Hemophilia A (some mutations)

X linked retinitis pigmentosa

B thalassaemia (some mutations)

Sickle cell anaemia

Myotubular myopathy type 1 (some mutations)

Congenital adrenal hyperplasia (some mutations)

Leucocyte adhesion deficiency type 1 (some mutations)

Any other diseases/mutations are considered and an estimate given on the development time – usually 3-6 months.

Patients and Physicians wanting additional information and pricing information for the Transport PGD program can call Mrs. S. Celani at 514-934-1934 extension (36852).