Can IVF detect Down syndrome?

Can IVF prevent Down syndrome?

Down syndrome is the result of a genetic anomaly and currently it cannot be managed or cured. While there is no cure, IVF in Cyprus helps intended parents prevent the genetic disorder caused when abnormal cell division results in an extra full or partial copy of chromosome 21. Thanks to advancements in DNA technology, IVF Cyprus can detect a variety of genetic disorders before birth, which gives parents the opportunity to have a healthy, biological child.

Preimplantation genetic testing refers to two types of tests that may be performed on embryos during IVF — Preimplantation Genetic Screening (PGS) Cyprus and Preimplantation Genetic Diagnosis (PGD) Cyprus. In addition to these tests, EuroCARE IVF Clinic in North Cyprus can perform Array Comparative Genomic Hybridisation (Array CGH) testing, which involves testing of all 22 sets of chromosomes plus the sex chromosomes (XX/XY).   

Our fertility specialists in Cyprus  perform these tests to determine if embryos are affected by genetic mutations, such as Down syndrome that often cause failed implantation and miscarriage. Embryos found to have Down syndrome are excluded from the embryo transfer during IVF treatment.

PGS, PGD and Array CGH are combined with IVF Cyprus, it decreases the risk of miscarriage and increases the likelihood of a successful pregnancy.

PGS Cyprus Genetic Testing

PGS (Preimplantation genetic screening) Cyprus is a genetic test that analyzes embryo cells to determine if there is a normal number of chromosomes (euploidy). An abnormal division of either sperm or egg cells can cause an embryo to have one more or one less chromosome in the cells. If an embryo is missing a chromosome (monosomy) or has an extra one (trisomy), it is called aneuploidy.

Trisomy of chromosome 21 can result in children having Down syndrome (Trisomy 21). Down syndrome affects 1 in 700 births around the world.

Prospective parents may select PGS Cyprus to prevent implantation of embryos affected by Trisomy 21.

Is PGS Testing in Cyprus Beneficial for Intended Parents?

Intended parents should consider PGS in Cyprus if they are at risk of passing a genetic disorder to their child. Other candidates for PGS testing in Cyprus include:

• Couples who have had a previous child with Down syndrome.
• Women who have had two or more pregnancy losses (recurrent miscarriage).
• Women who have experienced an implantation failure.
• Women diagnosed with unexplained infertility.
• Women older than 35.

PGS testing allows our EuroCARE IVF embryologist to evaluate the chromosomal composition of embryos and grade them based on quality. Only embryos that are chromosomally normal (euploid) will be used for the embryo transfer.

Is PGS Testing Accurate?

PGS testing is a highly advanced technology with an accuracy rate of 97 percent. The success rates of PGS Cyprus reach 75% for women under 35. Additionally, women after age 40 who choose to have PGS testing during IVF in Cyprus can reduce the risk of miscarriage by more than 45 percent.

PGD Cyprus Genetic Testing

PGD (Preimplantation genetic diagnosis) Cyprus analyzes embryos for specific genetic mutations that one or both intended parents carry or are suspected to carry. A family history of Down syndrome in one or both parents can increase the likelihood for a child to be born with the same genetic mutation.

The ultimate goal of PGD Cyprus is to select only chromosomally ‘normal’ embryos for transfer. This increases the chance of having children without Down syndrome.

When is PGD Testing Performed?

PGD testing is performed for intended parents with a known genetic disease or carriers of a genetic disease who wish to avoid having a child born with that disease. PGD testing is also recommended for couples with other known genetic abnormalities, women with multiple failed IVF cycles and women who have had multiple miscarriages due to a genetic or unknown cause.

Besides Down syndrome, PGD testing can detect other common genetic disorders such as:

• Sickle cell anemia.
• Muscular dystrophy.
• Cystic fibrosis.
• BRCA1 & BRCA2 mutations.
• Fragile-X syndrome.
• Tay-Sachs disease.

During PGD testing, our EuroCARE IVF embryologist will look into the genetic structure of each embryo and will choose only embryos that are disease-free and genetically normal. Only healthy embryos will be transferred.

Array CGH Test in Cyprus

Array CGH in Cyprus is a type of genetic testing used during IVF in Cyprus that screens all 22 sets of chromosomes plus the sex chromosomes (XX/XY).  This is a more detailed genetic testing that may be performed on embryos created through IVF. This procedure is required if our embryologist suspects that embryos may contain a difference in terms of gains or losses of chromosomes.

Array CGH Analysis

On day 5 of embryo development, a few cells will be removed in our lab for the Array CGH analysis. The same day, the embryos will be safely frozen.  During Array CGH at EuroCARE IVF Clinic, two genomic DNA samples from two closely related sources are compared to identify abnormalities in the number of chromosomes. At the same time, the woman will take medication to prepare her uterus for implantation. Once the test results are available, typically 1-2 months later, an embryo transfer will be scheduled at our fertility clinic in Cyprus. After the selection is made, only the best embryo(s) will be transferred to the woman’s uterus.

PGS Cyprus vs PGD Cyprus

PGS or PGD testing for IVF? PGS and PGD are two genetic tests that have a lot in common, but are also different in many ways:

• Procedure: Both PGS and PGD follow the same procedure except for the first step – embryo biopsy. During PGD Cyprus, the biopsy is performed on day 3 after fertilization. In PGS testing, the biopsy is at the blastocyst stage of embryo development. A few cells are extracted from the embryos for lab analysis. The embryos will be frozen during the procedure. Before transfer, frozen embryos are thawed and transferred as fresh embryos.
• Chromosome analysis: PGD Cyprus screens embryos for a specific genetic condition of only 5 chromosomes. With PGS testing, all 24 chromosomes are analyzed in our lab for potential abnormalities.

What are the Risks of Genetic Testing?

The health risks for children born after PGS or PGD testing are no different than the health risks associated with IVF. It is generally recommended the patient to undergo additional prenatal testing during her pregnancy to confirm the findings of the PGS or PGD testing.

What is Down syndrome?

Human genes determine how the body appears and functions. Down syndrome is a genetic disorder caused by the presence of extra full or partial copy of chromosome 21. This extra chromosome alters the course of development and causes the physical features associated with Down syndrome.

Down syndrome leads to a range of issues that affect the child both mentally and physically. Varying in severity among individuals, Down syndrome can cause intellectual disability and developmental delays. Down syndrome is a lifelong condition with no cure.

Down syndrome is the most common genetic chromosomal disorder and cause of learning disabilities in children. It also commonly causes other medical abnormalities, including heart and gastrointestinal disorders.

Symptoms of Down Syndrome

Down syndrome is associated with certain intellectual and developmental problems that may be mild, moderate or severe.

Intellectual Symptoms

• Short attention span
• Poor judgment
• Impulsive behavior
• Slow learning
• Delayed language and speech development

Physical Symptoms

Children and adults with Down syndrome have distinct facial features. Some of the most common features include:

• Flattened face
• Small head
• Short neck
• Eyes that slant upward
• Unusually shaped or small ears
• Broad, short hands with a single crease in the palm
• Relatively short fingers and small hands and feet
• Tiny white spots on the colored part (iris) of the eye called Brushfield’s spots
• Short height

Infants with Down syndrome may be average size, but typically they grow slowly and remain shorter than other children of the same age.

Intellectual Disabilities

Most children with Down syndrome have mild to moderate cognitive impairment. Language is delayed, and both short and long-term memory is affected.

Medical Conditions Associated with Down syndrome

People with Down syndrome are at increased risk for a range of other health conditions, including:

• Congenital heart defects. Children with Down syndrome are usually born with some type of congenital heart defect that may require surgery at an early age.
• Gastrointestinal disease. These may include abnormalities of the intestines, esophagus, trachea and anus. It also involves the risk of developing digestive problems, such as gastrointestinal blockage, heartburn or celiac disease.
• Autoimmune disease. Children with Down syndrome are at increased risk of developing autoimmune disorders, some forms of cancer and pneumonia.
• Sleep disorder. Sleep apnea is a serious sleep disorder where breathing stops and starts in a continuous repetitive cycle. People with Down syndrome are at greater risk of developing severe sleep apnea.
• Obesity. People with Down syndrome have a greater tendency to be obese than unaffected people.
• Spine problems. Some people with Down syndrome may be affected by congenital spinal defects that causes instability and puts them at risk of serious injury from overextension of the neck.
• Leukemia. Young children with Down syndrome have an increased risk of leukemia.
• Cognitive disorder. People with Down syndrome have a greatly increased risk of dementia after age 50. Down syndrome also increases the risk of Alzheimer’s disease.
• Other problems. Down syndrome may also be associated with other health conditions, including autism, problems with hormones or glands, dental problems, seizures, ear infections, and hearing or vision problems.

Causes of Down Syndrome

Down syndrome is caused by having three copies of the chromosome 21, rather than the usual two. The parents of the affected child are typically genetically normal. Parents who have one child with Down syndrome, have about a 1 percent risk of having a second child with the syndrome.

Is Down syndrome genetic?

Most cases of Down syndrome are not inherited. Only translocation Down syndrome can sometimes be passed onto the child. The syndrome is generally caused by a mistake in cell division before or at conception.

Types of Down Syndrome

Any one of three genetic variations can cause Down syndrome:

• Trisomy 21. Most of the times, Down syndrome is caused by Trisomy 21, also known by the karyotype 47, XX,+21 for females and 47, XY,+21 for males. Trisomy 21 is when the person has an extra copy of the chromosome 21, instead of the usual two copies. As a result, the baby has 47 chromosomes in all cells than the normal 46. This may be caused by an abnormal cell division during the egg or sperm development. Trisomy 21 occurs in 95% of cases.
• Mosaic Down syndrome. In Down syndrome, mosaicism means that some cells of the body have trisomy 21, and the others have the typical number of chromosomes. Mosaicism is caused by abnormal cell division after fertilization. Mosaic Down syndrome is a rare condition that occurs in 2,5% of cases.
• Translocation Down syndrome. The extra chromosome 21 may also occur due to a Robertsonian translocation (rearranged genes) in 2–4% of cases. In this case, the long arm of chromosome 21 is attached to another chromosome, often chromosome 14. This may be a new genetic mutation or previously present in one of the parents. The parent with such a mutation is usually both physically and mentally normal, but has a higher chance of producing egg or sperm with an extra chromosome 21. The translocation occurs before or at conception. These children have the usual two copies of chromosome 21, but they also have a chromosome 21 attached to another chromosome in their body. This type of Down syndrome is not related to the mother’s age. Children may or may not have Down syndrome, but they have a higher chance of passing the mutation onto their children. This is known as familial Down syndrome.

Down syndrome Risk Factors

Some of the risk factors for Down syndrome include:

• Genetic translocation for Down syndrome. If one or both parents are affected by or carry a genetic translocation (rearrangement of genes) for Down syndrome, they are more likely to have children born with the syndrome.
• Previous pregnancy affected by Down syndrome. Parents who have one child with Down syndrome have higher chances of conceiving a child with Down syndrome.

Conclusion

During IVF in Cyprus, couples may choose to have PGS, PGD or Array CGH testing to identify genetic abnormalities in the embryos, such as Down syndrome. This allows only embryos free of genetic defects to be used for the IVF embryo transfer.

These genetic tests have two important benefits:

• Preventing genetic disorders from being passed onto the child(ren).
• Increased chance of a healthy pregnancy and successful birth through IVF in Cyprus.

If you are interested in learning more about the genetic testing available at EuroCARE IVF in North Cyprus, consult with our fertility specialists to discuss available options.