Breakthrough genetic test reveals genetic diseases associated with ultrasound abnormalities in the embryo
An innovative test reveals the genetic disorder in a fetus when the 1st or 2nd trimester ultrasound reveals abnormal findings.
The test is called Fetalis®, the first of its kind internationally, opening new horizons in prenatal diagnosis and was developed by Greek scientists from InterGenetics – Diagnostic Genetics Center in Athens.
The new test analyzes, using advanced genomic techniques, the DNA of 758 carefully selected genes associated with genetic diseases which may be associated with ultrasound abnormalities observed during conventional ultrasound examinations during pregnancy.
«During ultrasound examination of all pregnancies approximately 3-5% present with ultrasonographic findings related to congenital anomalies of the fetus, and despite this relatively low frequency they account for about 20-25% of perinatal deaths» commented Dr. Constantinos Pangalos, Medical Geneticist, Director of InterGenetics – Diagnostic Genetics Center, who designed the Fetalis® test together with molecular geneticist Dr. Christopher Konialis.
Dr. Pangalos presented preliminary results of the Fetalis® test during the recent European Society of Human Genetics congress held in Barcelona, where he noted that most fetal ultrasonographic abnormalities are be due to genetic causes while others may not. Genetic causes are related to chromosomal abnormalities, which involve gain or loss of genetic material, or gene mutations involving changes in the DNA sequence.
The first choice for the diagnosis of ultrasonographic abnormalities in pregnancy is the application of molecular karyotype, which detects chromosomal abnormalities. “But these abnormalities relate only to about 10-15% of congenital anomalies of the fetus and thus the majority are related to gene mutations and remained undetected until now, resulting in only vague assumptions as to the health of fetus. These cases ended either in a ‘blind’ termination, or to the acceptance of the danger of an underlying serious genetic disease, “explained Professor Pangalos.
For the detection of gene mutations, options until now were very limited. As a result, genetic testing was largely ineffective, while in addition we were unable to predict with accuracy the likelihood of recurrence of the pathological findings in subsequent pregnancies.
“All these problems may now be solved through the pioneering Fetalis® test, which is based on the advanced technique of massive parallel sequencing (NGS) of several genes, allowing a very dynamic and efficient diagnostic approach even for complex cases” announced at the congress Prof. Pangalos. “In fact, the implementation of the Fetalis® test in conjunction with prenatal molecular karyotype, may reveal almost 90% of all possible genetic abnormalities in fetuses with ultrasonographic findings.”
Dr. Pangalos presented in the Congress for the first time internationally the initial results of the implementation of the Fetalis® test in 15 pregnant women with fetal ultrasonographic findings. The test revealed the genetic cause in 8 cases, of which 7 were terminated. In the remaining 7 cases a pathogenic mutation was not revealed and the pregnancies were continued, leading to the birth of healthy babies, which so far do not show any pathological features.
The test requires embryonic cells, which may be obtained by amniocentesis or trophoblast biopsy, both of which are currently performed with safety.
The results of the Fetalis® tests should be accompanied by appropriate genetic counseling by an experienced clinical geneticist and always in cooperation with the obstetrician and the fetal medicine specialist.