PGS (preimplantation genetic screening) Spain

Preimplantation genetic screening (PGS) is the cutting–edge and the most secure abnormal chromosomal content authentication technique ever in IVF cycles. Preimplantation genetic screening is an embryo biopsy that is an essential but more invasive procedure compared with ICSI. It is performed for screening the embryonic content for aneuploidy (chromosome abnormalities) in couples with recurrent miscarriages, multiple failed IVF cycles or advanced maternal age.

PGS (Preimplantation Genetic Screening) price is 1630 Euros.

SCREENING OF TRANSMISSIBLE GENETIC DISEASE

Nowadays, the couples suffering from any hereditary disease and wishing to start a family can have healthy children thanks to In Vitro Fertilization and Preimplantation Genetic Diagnosis.

Preimplantation Genetic Diagnosis (PGD) has two categories – “high–risk PGD” (preimplantation genetic diagnosis) and “low–risk PGD” (preimplantation genetic screening). PGD and PGS are performed prior to embryo transfer.

Preimplantation genetic diagnosis (PGD) is performed to investigate the embryonic genetic content for transmitting a genetic or chromosomal abnormality).

Preimplantation genetic screening (PGS) is performed to investigate the embryonic content for chromosomal abnormalities that cause recurrent miscarriages or recurrent failures of IVF cycles.

PGD is performed for couples at high risk of transmitting a genetic or chromosomal abnormality to their children to exclude transferring the embryos with abnormal genetic content. PGGD is done to detect single gene defects (autosomal recessive, autosomal dominant and X–linked disorders) and chromosomal abnormalities (structural variation and fusion detection of the chromosomal translocations, structural aberrations, balanced Robertsonian translocations, reciprocal translocations, etc.).

PGS is performed for the couples undergoing IVF treatment to boost IVF success and exclude the causes that lead to recurrent miscarriages. PGS is performed in the following cases: women of advanced maternal age, couples with repeated IVF failure, and couples with normal karyotypes who have experienced recurrent miscarriages in their medical history.

For those patients with a medical family history of genetic disease or suffering from pathologies that can be transmitted to their children, it’s possible to investigate whether there is a genetic cause before starting any assisted reproduction treatment.

There are genetic diseases causing infertility to those who suffer from them and that can also be transmitted to children. Some of the most known diseases such as X-fragile or gonadal dysgenesis can be studied and be eradicated in a family by selecting the embryos free from the disease through what is known as Pre-implantation Genetic Screening techniques.

In those cases where there is no concrete disease, but previous clinical history recommends it, the analysis of the couple’s chromosomes is performed to check whether they are normal as well as the analysis of sperm DNA alterations that can cause abnormalities, miscarriages or other chromosome diseases. Thanks to Preimplantation Genetic Screening we can study the embryo’s chromosomes and select the ones without alteration before transferring them into the uterus of the future mother.

RECURRENT MISCARRIAGES ASSESSMENT

Miscarriages can be caused by hormone alterations, infectious agents, anatomic problems or immune system’s rejections, but the majority happens for a genetic reason. Several times recurrent implantation failures are considered early miscarriages and are treated in the same way.

In order to know if there is a genetic cause, there are different tests to study the implantation process in the woman and to detect chromosome alterations in the embryo before its transfer into the uterus.

This makes possible to determine the reason for the miscarriages for 60% of the cases.

WHAT IS PREIMPLANTATION GENETIC SCREENING?

Preimplantation Genetic Screening (PGS) is a very early diagnostic technique to detect abnormalities in the genes or chromosomes of the embryos obtained by in vitro fertilization before they are transferred into the woman’s uterus for further gestation.

One or two cells of the embryos are analyzed to obtain the diagnosis. By performing the diagnosis before the embryo’s implantation, the advantage is that we are minimizing the risk of having to interrupt the gestation once that the patient is already pregnant.

PGS is recommended not only in case of monogenic diseases but also in cases of chromosomal numerical abnormalities and chromosomal structural abnormalities.

SCREENING OF ALL THE EMBRYO’S CHROMOSOMES: CGH ARRAYS

Comparative genomic hybridization (CGH) is a state–of–the–art genomic technique that is performed to investigate the high genetic content variability allowing to study the 24 chromosomes of an embryo (22 + X,Y) with a microchip of DNA (array). The previous techniques investigated only 9 or 12 chromosomes of the 23 pairs. CGH represents an inclusive analysis and identifies the disease genes.

Microscopic genomic deletions and duplications constitute approximately up to 15% of all genomic mutations underlying the monogenic diseases.

Microarray–based comparative genomic hybridization (array CGH) allows to “design” the real mapping of genomic copy number alterations at the microscopic level. This micro genomic copy designed version makes it possible to “visualize and reconnect” disease phenotypes to gene dosage alterations.

CGH is the molecular karyotyping technique that visualizes the chromosomes and allows sensitive and specific detection of single copy chromosomal number changes at the microscopic level throughout the entire embryonic genome.

CGH detects up to 50% of abnormalities. It is recommended for the couples with the previous history of recurrent miscarriages and repeated implantation failures in previous IVF.

PGD FOR GENDER SELECTION

In couples with the increased risk of transmitting X–linked diseases, we analyze the sex chromosomes to determine the sex of the embryos, being able to select the ones suitable to be transferred.

PREIMPLANTATION HLA TYPING

For the past few years, the couples having children affected by a severe disease (immune–deficiency illnesses, congenital metabolic defects, hemoglobinopathies, lymphoma, leukemia, myelodysplastic and myeloproliferative syndromes) may request the fertility clinics to perform IVF cycle with HLA typing techniques to select histocompatible embryos for future transplants.

At present, it is possible to perform PGD in tandem with preimplantation HLA typing (human leukocyte antigen typing) of preimplantation embryos for hematopoietic stem cell (HSC) transplantations. In other words, it is possible to design the embryo that would be an HLA identical donor sibling to save the life to the child affected by severe genetic disease.

HLA typing of embryos is performed for further usage of haematopoietic stem cells (HSC) from the umbilical cord blood or the bone marrow of a future donor child to save an existing recipient sibling’s life.

Nowadays, we are provided with the greatest set of genetic markers of the market to find the maximum level of compatibility and to maximize chances of embryo transfer in each case.