Embryonic Preimplantation Genetic Diagnosis (PGD) or Preimplantation Genetic Testing for monogenic diseases (PGT-M)

The number of IVF cycles after PGD (or PGT-M, Preimplantation genetic testing for monogenic/single gene diseases): 16*

*for the families after genetic examination, in which the hereditary genetic disorder is molecularly confirmed. Currently iVF Riga Clinic has embryos tested for the following genetic abnormalities:

  • Huntington’s chorea – mutations in the HTT gene;
  • Thoracic Aortic Dissections – mutations in the ACTA2 gene;
  • Ichthyosis - mutations in the ALOX12B gene;
  • Neuronal ceroid lipofuscinosis – mutations in the TPP1 gene;
  • GM1-Gangliosidosis – mutations in the GLB1 gene;
  • Myotubular myopathy – mutations in the MTM1 gene;
  • Duchenne and Becker muscular dystrophy – mutations in the DMD gene

For families in which monogenic hereditary diseases (which occur due to changes in a single gene) are passed down from generation to generation or a similar disorder has already been detected in one of the children, the question about the possibility to diagnose the disease as early as possible is of high importance. Up until now, such diagnosis could only be made during pregnancy, however, oftentimes it lead to a difficult decision of pregnancy termination in cases where the diagnosis of the child’s disease was confirmed.

Since 2015, the Genetic centre iVF Riga offers its patients an opportunity to analyze embryonic cells in order to determine which of the embryos did not inherit the mutation (or mutations) of the gene, thus allowing to continue the pregnancy, knowing that the further spread of the disease in the family has been stopped. In order to carry out the given analysis, (PGD - preimplantation genetic diagnosis, or PGT-M, testing for monogenic diseases) the hereditary genetic disorder has to be molecularly confirmed. The unique preimplantation genetic diagnosis (PGD) or preimplantation genetic testing for monogenic diseases (PGT-M) allows to select viable embryos at an embryonic level, thus ensuring the birth of healthy baby.

Important to know: even if the patients or their children have been diagnosed with a genetic disorder, it does not mean that a healthy child cannot be born in this family!

The Genetic centre iVF Riga is currently the only one in the Baltic countries offering embryonic Preimplantation Genetic Testing – PGS and PGD (or, according to the new terminology, PGT-A and PGT-M). These methods make it possible to choose the best and most viable genetically competent embryos, thus effectively increasing the likelihood of implantation, clinical pregnancy and successful already after the first cycle of PGS/PGD (PGT-A/PGT-M).

There are many diseases for which PGD (PGT-M) is recommended. Although it might seem that these diseases occur rarely, in general, they affect a significant part of the population. Most common genetic disorders are:

Dominantly transmitted disorders — can be passed down from generation to generation

  • Huntington’s chorea — progressive neurodegenerative brain disease; at the initial stage characterized by uncontrollable disorderly movements (chorea).
  • Achondroplasia (dwarfism) — genetic disorder caused by mutations in the FGFR3 gene, which leads to uneven growth of the skeleton.
  • Charcot–Marie–Tooth neuropathy — hereditary sensory-motor nerve disorder characterized by muscle weakness and muscle atrophy of the distal extremities.

Recessively transmitted disorders — often occurs in brothers and sisters

  • Cystic fibrosis — genetic disease, based on the mutation in the CFTR gene and characterized by lesions of exocrine glands, severe complications of the respiratory and gastrointestinal tract.
  • Phenylketonuria — inherited inability to metabolize amino acid phenylalanine; causes brain and nerve damage if left untreated.
  • Spinal muscular atrophy — genetic disease characterized by dysfunction of the spinal cord nerve cells, muscle weakness and atrophy, leading to immobilization.

X-linked (connected with the X chromosome) transmitted disorders — most often occur in males

  • Fragile X chromosome syndrome — hereditary disease caused by mutations in the FMR1 gene,  characterized by premature ovarian failure or exhaustion, accompanied by mental retardation.
  • Myotubular myopathy — congenital myopathy with severe weakness of the facial muscles, disorders of swallowing and respiratory functions.
  • Hemophilia — bleeding disorder that slows down the blood clotting process.
  • Duchenne and Becker muscular dystrophy — genetic disorders, that affect the structure of the muscle fibers, thus causing severe muscle weakness and loss of ambulation. These disorders can also lead to skeletal deformities, heart and respiratory failure, endocrine and mental disorders.

PGD/PGT-M - step by step

  1. Geneticist consultation and medical history review (the hereditary genetic disorder has to be molecularly confirmed) 
  2. Personalized PGD/PGT-M test for this case design & preparation
  3. IVF/ICSI manipulation
  4. Cultivation of the received embryos up to day 5
  5. Embryo biopsy – several trophectoderm cell collection without harming the embryo
  6. Embryo freezing (vitrification) for later use
  7. PGD/PGT-M - preimplantation genetic diagnosis, the examination of certain monogenic disease
  8. PGS/PGT-A for transferable embryos
  9. Embryo transfer
  10.  Postnatal confirmation of baby’s genotype