Assisted Reproductive Technology development started after the breakthrough of Patrick Steptoe and Robert Edwards in the successful birth of a baby in 1978, after in-vitro fertilization and embryo transfer.
The same knowledge to life in West Africa by Ashiru and Giwa-Osagie at the Lagos University Teaching Hospital a few years afterward, increased knowledge in the ART field, and led to the development of Preimplantation Genetic Diagnosis.
Over the last 12 years, we have performed PGD (diagnosis) and PGS (screening), and most recently PGT, at the Medical Art Centre, for hundreds of couples for screening abnormal chromosomes, family balancing, and sickle cell screening.
PGT is now used to classify PGD and PGS.
PGT is divided into three sections;
- PGT-M
- PGT-SR
- GTA
PGT-M is for monogenic disorders.
It tests for single-gene disorders, which may or may not be sex-linked.
A child inherits X-linked disorders from a mother who is a carrier. They are passed down through an abnormal X chromosome to boys who do not receive the father’s normal X chromosome.
Because the X chromosome is transferred through the mother to the offspring/embryos, affected men produce unaffected sons. Still, their daughters have a 50 per cent chance of being carriers if the mother is healthy.
PGT-M is used for the following: sickle cell disease, Hemophilia, fragile X syndrome; most neuromuscular dystrophies (of which about 900 neuromuscular dystrophies have been identified), and hundreds of other diseases are all sex-linked recessive disorders.
According to the World Health Organization, sickle cell disease is the most prevalent genetic disease in the African region.
While 75 per cent of patients with SCD live in sub-Saharan Africa, Nigeria alone accounts for more than 100,000 births each year.
It cannot be overemphasised that sickle cell disease is fast becoming an African disease. In recent times, we have seen couples who were able to have healthy, unaffected babies by coming in for IVF treatment, where PGT led to the selection of only unaffected embryos for transfer.
PGT-A is used for sex selection for family balancing only, a service readily available at the Medical Art Centre for couples looking to have a balanced family locally and internationally.
The Y chromosome is the determining factor for sex. Men have XY as their sex-determining chromosomes, while women have XX as theirs.
A man’s sperm, therefore, either carries the X or Y chromosome, while a woman’s egg always carries an X chromosome.
Research has shown that the X and Y chromosomes are not evenly distributed in any given population of sperm cells from the same man. However, from our experience, we have had a couple who, out of 15 embryos, had two abnormal male and 12 female embryos that were automatic carriers of an X-linked disease, because the male partner was a carrier (his X chromosome).
The male partner was advised to detoxify at the MART Life Detox Clinic and was also given some orthomolecular supplements for 30-60 days.
The IVF cycle was repeated at the Medical Art Centre and PGT-M was performed on the resulting embryos from this new cycle for male sex selection since only the male embryos would be free from the man’s X-linked disease. The result was surprising as the resulting embryos had more male embryos than the previous PGT.
PGT-SR tests for chromosomal structural abnormalities by assessing each chromosome. It is used for chromosomal diseases in which fluorescent in situ hybridization can identify a variety of chromosomal rearrangements, such as translocations, inversions, and deletions.
FISH uses telomeric probes that are unique to the loci that are being studied. Because earlier conceptions resulted in chromosomally imbalanced embryos spontaneously miscarried, some parents may never have been able to produce a successful pregnancy without PGD.
PGT-A for aneuploidy tests for embryos with abnormal numbers of chromosomes. Humans have 46 chromosomes in total: 23 from each parent.
Aneuploidy occurs when there is an increase or decrease in chromosome numbers. Aneuploidy is to blame for the majority of early pregnancy losses.
The probability of first and second-trimester loss is significantly lowered since only chromosomally normal embryos are placed into the uterus. The following are examples of primary candidates for PGT-A: women who are near or in their menopausal age; couples who have had previous miscarriages; couples who have had many IVF failures.
Our mission at Medical Art Centre is to provide state-of-the-art technology to manage infertility and other reproductive health problems.
Through PGT, we are continually providing solutions to couples with a history or who are carriers of the single-gene disorder.
The article is particularly relevant as there is a need for more public awareness of this technology.
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