FAQ (Frequently asked questions)

What is the PrenatalSAFE® test?

PrenatalSAFE® is the first prenatal test able to detect from the most common fetal aneuploidies (13, 18, 21, X and Y) up to the rarest aneuploidies (all chromosomes of the fetal karyotype) reaching a level of information today only by invasive techniques. PrenatalSAFE® is also the only non-invasive prenatal test able to highlight subchomosomal structural anomalies on the whole fetal karyotype and mutations related to serious genetic diseases. The test provides information on the sex of the fetus (optional).

What information does the PrenatalSAFE® test provide?

PrenatalSAFE® 3 determines the presence of the most common fetal trisomies, such as those related to chromosomes 21, 18 and 13, analyzing fetal DNA circulating in the maternal blood. 
PrenatalSAFE® 5 evaluates the presence of fetal aneuploidy of chromosomes 21, 18, 13 and of sex chromosomes (X and Y), and includes the determination of fetal sex (optional). 
PrenatalSAFE® PLUS, in addition to the PrenatalSAFE® 5 test, provides a further study to identify the trisomies of chromosomes 9 and 16 and the presence of some small structural chromosomal alterations, or 6 among the most common microdelection syndromes. 
PrenatalSAFE® KARYO is the first non-invasive prenatal test able to detect aneuploidy and structural chromosomal alterations (segmental deletions and duplications) on each chromosome of the fetal karyotype reaching a level of information comparable to that obtained by invasive techniques. 
PrenatalSAFE® KARYO PLUS includes screening of 9 most common microdeletion in addition to findings of PrenatalSAFE® KARYO. 
PrenatalSAFE® COMPLETE is the first non-invasive screening test able to detect aneuploidy of each chromosome of the fetal karyotype and mutations responsible for serious genetic diseases. The test is the result of a combination of PrenatalSAFE® KARYO and GeneSAFE™, a new screening test that allows the identification of genetic hereditary diseases with de novo onset in the fetus. 
PrenatalSAFE® COMPLETE PLUS includes PrenatalSAFE® KARYO PLUS, and GeneSAFE™, a new screening test that allows to identify genetic diseases with hereditary transmission and with de novo onset in the fetus.

Who can undergo the PrenatalSAFE® non-invasive prenatal test ?

PrenatalSAFE® can be undertaken by all pregnant women with a gestational age of at least 10 weeks. PrenatalSAFE® can be performed on single pregnancies, pregnancies from in vitro fertilization (IVF, ICSI) both homologous and heterologous, twin pregnancies even if obtained with assisted, homologous and heterologous fertilization techniques. PrenatalSAFE® COMPLETE  and PrenatalSAFE® COMPLETE PLUS are particularly suitable for couples with advanced paternal age.

When can the PrenatalSAFE® test be performed ?

PrenatalSAFE® is offered from the 10th week of gestation. There is no deadline to perform the test because the free fetal DNA remains in the mother's bloodstream throughout the duration of the pregnancy.

How is the PrenatalSAFE® test performed ?

A simple blood sample from the future mother is needed. You do not need to be fasting to do it.

How accurate is the PrenatalSAFE® test ?

The PrenatalSAFE® test has a sensitivity and specificity higher than 99% with a very low incidence of false positives, below 0.1% of cases. 
PrenatalSAFE® detects abnormalities affecting the fetal genome even at low quantities of fetal DNA (FF≥ 2%).

 

What kind of information is reported on the PrenatalSAFE® test reports ?

The results of the test are provided in clear and defined terms, as POSITIVE or NEGATIVE, ie presence / absence of the anomaly found within the limits of the method used.

Is the PrenatalSAFE® test similar to the other first and second quarter screening tests?

No. Screening tests are indirect statistical tests that are based on ultrasound examinations on the fetus and / or biochemical investigations on maternal blood, by which some substances are measured which can vary in quantity if there are some chromosomal pathologies. The PrenatalSAFE® test, while a screening test, is a direct analysis of cell-free fetal DNA and analyses the fetal DNA circulating in the maternal blood with great accuracy.

Is PrenatalSAFE® more reliable than non-invasive prenatal screening tests currently available?

Prenatal screening tests, such as the bi-test, may present a high risk for fetal trisomy even if it is actually a negative (false positive) result or may present a low risk for fetal trisomy, whereas in reality it is a positive pregnancy (false negative). 
These non-invasive tests, such as the combination of free-b-HCG and PAPP-A proteins with nuchal translucency, have a false positive rate of up to 5% and do not detect about 10-15% of fetal trisomy 21 cases. With the PrenatalSAFE® test, the percentages of false positives and negatives fall to 0.1%.

Is PrenatalSAFE® a safe test or does it involve risks?

The PrenatalSAFE® test is completely safe for both the mother and the fetus. Diagnostic tests such as amniocentesis or villocentesis (CVS), although accurate for the diagnosis of fetal trisomies, are invasive and present a risk of non-negligible abortion and require appropriate antibiotic therapy.

Why choose PrenatalSAFE® compared to other fetal DNA analysis from maternal blood?

Each PrenatalSAFE® uses NGS sequencing technology (Next Generation Sequencing) of the entire human genome, unlike other commercially available tests that instead employ a targeted diagnostic strategy, in which the process is limited to chromosomes 21, 18, 13 , X and Y only. 

The advantages produced by this technology are considerable:

  • Possibility of analysis of the entire genome for aneuploidy and structural anomalies in each chromosome.
  • Possibility of detecting mutations responsible for serious genetic diseases.
  • High sensitivity, even at a low percentage of fetal fraction, with a consequent reduction in the incidence of need for new collection (<1%).
  • Greater reliability of the results, with a consequent increase in the detection rate (> 99%) and reduction of the incidence of false positives (<0.1%),
  • Using an algorithm of bioinformatics analysis of the latest generation that evaluates the actual data (quantitative) from the analysis of sequencing, no associate of a priori risk assessments (eg. Age of the patient) or gestational age or weight of the patient.
  • Results of the examination provided in clear and defined terms, such as POSITIVE or NEGATIVE, ie presence / absence of anomaly, and no longer in terms of percentage of risk (high / low risk) as for the screening tests of the 1st and 2nd trimester.
  • Test is also suitable in pregnancies obtained with assisted fertilization techniques (homologous or heterologous).
  • Fast reporting times (from 3 working days)
  • Less blood required for the test (8-10 ml in a single tube).
Furthermore, PrenatalSAFE® is entirely performed in Italy at our laboratories in Rome and Milan. Unlike other tests on the market, it is NOT sent at any stage of the service process to third-party facilities located in the US or China.

What are the free services offered with PrenatalSAFE®

 

  • Refund of test fee in case of inconclusive result
  • Follow-up of pathological results
  • Free blood sample transport : certified according to UN3373, and free shipping service of biological samples to the GENOMA laboratory by express courier.
  • All inclusive customer assistance : from sample shipment to reporting.
  • Specialist and scientific support : Molecular biologists and qualified geneticists are always available to assist patients on the interpretation of results.
  • Educational : GENOMA provides its patients with information on the test and the dissemination brochures.

 

What are fetal aneuploidies?

They are chromosomal abnormalities characterised by alterations in the number of chromosomes, ie by a greater or fewer number of chromosomes compared to the standard number. We speak, for example, of trisomy, when there is the presence of an extra chromosome or of monosomy, when there is an absence of a chromosome. 

TRISOMY 21
It is caused by the presence of an extra copy of chromosome 21 and is also known as Down Syndrome. It is the most common genetic cause of mental retardation. Trisomy 21 is estimated to affect approximately 1 infant in every 600. Children with Down syndrome have a delay in cognitive ability and physical growth and are also more likely to develop certain diseases. Down syndrome does not manifest itself in the same way in all the people affected and there is no way to establish the level of disability before birth. The probability of having a Down syndrome child increases with the age of the mother, although women of all ages can have a child with Down syndrome, regardless of their parents' ethnic group. 

TRISOMY 18

It is caused by the presence of an extra copy of chromosome 18. Also known as Edwards syndrome, is associated with a high abortion. It causes serious mental retardation. Infants with trisomy 18 often have congenital heart defects as well as other pathological conditions that reduce their life expectancy. It is estimated that trisomy 18 is present in 1 / 5,000 births. 

TRISOMY 13
It is caused by the presence of an extra copy of chromosome 13. Also known as Patau Syndrome, it is associated with high abortion. Infants with trisomy 13 have numerous cardiac defects, manifesting severe cognitive deficits and developmental disabilities. They do not survive beyond the first months of life. It is a less common condition of Down syndrome, which occurs in about 1 in 16,000 newborns. 

Analysis of chromosomes X, Y

Sex chromosomes X and Y are associated with sex: normally, females have two X chromosomes, while males have an X chromosome and a Y chromosome. In general, abnormalities due to the number of sex chromosomes do not cause severe cognitive deficits or physical-motor development. Early detection can help these children receive the services they need to reach their full potential. Overall, about 1 newborn in 500 is born with an abnormality of sex chromosomes. 
The aneuploidies of the sex chromosomes are the following: 

Turner Syndrome or Monosomy X:It is the most frequent aneuploidy of sex chromosomes. Most of the girls affected by Turner's syndrome have only one copy of the X chromosome. Many of these pregnancies go into miscarriage. Women with Turner's syndrome are usually shorter than average. Their puberty is delayed or completely absent and can be sterile. Most demonstrate normal cognitive abilities, although some present learning difficulties. Women with Turner's syndrome may also have heart or kidney problems. 

Klinefelter syndrome (XXY):Male children with Klinefelter syndrome have two X chromosomes and one Y chromosome. These are children with a tendency to be taller than average, whose puberty may be delayed or completely absent and which are often sterile. Most demonstrate normal cognitive abilities, although some may have psychological or learning difficulties. 

Triple X Syndrome (XXX) and Jacobs Syndrome (XYY)
Subjects with these conditions may be taller than average and usually have normal cognitive abilities. In some rare cases psychological or learning problems can occur. These conditions are not associated with birth defects and may remain undiagnosed. People with these syndromes may have normal fertility.

What are Microdelections / Microduplications?

Microduplications and microdelections are structural chromosomal anomalies that are characterised by the loss (microdelection) or by the duplication (microduplication) of a small tract of a chromosome and, consequently, of the genes located on that chromosomal fragment. 
These alterations cause syndromes of clinical importance depending on the chromosome involved, the region involved and the size of the lost or duplicated region. This kind of chromosomal abnormalities can not be identified with traditional cytogenetic techniques