PGD with PCR
Our ex-patient Lucy explains how she underwent PGD PCR in Sanatorium Helios, which enabled her to have a healthy child without a rare hereditary disease – OTC deficiency (a disorder of the urea cycle).
Lucy and her husband Peter decided to start a family. They had a healthy son, Tommy. After some time Lucy got pregnant again. After a trouble-free pregnancy and childbirth they had another son Martin. Postpartum adaptation, as Lucy described, was all right. 48 hours after birth but boy got convulsions, breathing issues, great circulatory problems, and fell into a deep coma. He was rushed by helicopter to a specialized clinic in Prague. Despite all the efforts and the care of doctors the boy died.
My Son was diagnosed with OTC deficiency
“When Martin died,” says Lucy, “the doctors told me that he had very high levels of ammonia in his blood. They had suspected severe inherited metabolic disorder of the urea cycle that removes ammonia from the body. We agreed to blood collections of Martin and other family members. “
Examination of DNA in the gene for OTC revealed the presence of a pathogenic mutation. This is why Martin died. Lucy was a carrier of the mutation.
“I was explained,” continued Lucy, “that this disease is linked to chromosome X. My daughters will be either healthy or symptomless carriers like me, with the probability of 1:1. My future sons are likely either to be ill, or healthy.”
The family did not want to risk birth of another affected child
Lucie and Peter longed for another child, but feared the birth of another affected child. “If concieve naturally, there will be a risk that we experience again what happened with Martin. And we did not want this to happen again, it was too painful, “said Lucy. “We consulted our geneticist and she advised us Sanatorium Helios and preimplantation genetic diagnosis”.
New PGD test developed specifically for the family
Clinical geneticist and PGD specialists of Sanatorium Helios explained to the couple necessary steps needed to create specific test directly for their family. According to this assay it is possible to examine embryos of the pair in order to search OTC deficiency before they transfer the embryos into the uterus. Only those embryos that do not carry the mutation are then used. “Everything was explained in detail. About two months were needed to develop the test and to verify that everything works as it should, “says Lucy.
Special PGD PCR test allows you to select a healthy embryo
Lucie underwent an IVF cycle and 8-quality embryos were obtained. But 6 of them had a mistake in the gene for OTC deficiency. “If you choose to conceive naturally, it’s like playing Russian roulette“, she says. One of the two healthy embryos was transferred into the uterus. “Unfortunately, I did not get pregnant the first time. Over the next month I had another transfer of the embryo that was frozen. A pregnancy test was positive and resulted in the birth Natalie. In a few months, she will be celebrating her second birthday. She’s completely healthy. “
“It’s all pretty simple”
“The use of IVF and PGD had great importance for us, because we ensured that our child will not have a serious genetic disease. Everything seemed to be so simple, the technology is amazing. Previously, couples could choose to either live their lives without children, or to risk terminating their pregnancies or having disabled kids. But now they have a chance to have a healthy family. We take our Natalie as a great gift. Every day, we are so thankful to have her. And she is healthy, “Lucy ends her story.
Polymerase chain reaction (PCR) is a molecular biology technique. It is a quick and simple multiplication of a selected DNA segment. PCR is used to create up to many millions of copies of a particular stretch of DNA, which allows the analysis of DNA from very small amounts of starting material (eg., Ooe or more cells of the embryo). Subsequently, it is then possible to perform linkage analysis, that is within the PGD specific for the particular family and disease.
How is PGD-PCR performed?
PGD requires an IVF treatment.
After the egg collection, their fertilization and a 5-6 days culture, a biopsy is performed on suitable embryos (a few cells are removed) – see the video of biopsy.
Biopsied cells are subsequently tested. Healthy embryos are introduced (transferred) into the uterus of the patient, or are frozen and then stored for further use.
List of the best known monogenic disorders:
PGD-PCR tests can be performed on each monogenic disease, for which we know the mistake-mutation
Becker muscular dystrophy
Deficiency of alpha-1-antitrypsin (AAT)
Duchenne muscular dystrophy
Hereditary diffuse gastric carcinoma (E-cadherin)
Hereditary breast cancer (BRCA1, BRCA2)
Facioskapulohumerální muscular dystrophy
Familial adenomatous polyposis
Fragile X Syndrome
Charcot – Marie – Tooth syndrome
Chronic granulomatous disease
Congenital adrenal hyperlpasie
Congenital nephrotic syndrome
Myotonic muscular dystrophy
Polycystic kidney disease
Sickle cell anemia
Spinal muscular atrophy
Von Hippel-Lindau syndrome
Congenital hearing loss (connexin 26)