Research studies demonstrating the viability of an approach to routinely detect the presence of fetal DNA in a mother's blood to accurately diagnose or rule out genetic defects -- as early as the first trimester -- was presented at the 27th Annual Meeting of the Society for Maternal-Fetal Medicine being held in San Francisco.
This future diagnostic technology, currently under development at Sequenom, Inc. shows promise that a universal alternative to such invasive genetic screening procedures as amniocentesis and chorionic villus sampling, may be available in the future.
These implications are important to women with high-risk pregnancies, in that this future non-invasive screening technique will have significant benefit to all expectant mothers, especially on the heels of new guidelines endorsed by the American College of Obstetricians and Gynaecologists (ACOG) that call for risk assessment of all pregnancies for fetal chromosomal abnormalities.
Previous guidelines recommended testing women 35 years and older using amniocentesis or chorionic villus sampling, both considered invasive procedures that carry risks. ACOG now recommends screening before the 20th week of pregnancy using a less invasive screening option that includes ultrasound in conjunction with the measurement of certain blood hormones.
Invasive techniques involve sampling amniotic fluid that surrounds the baby in the uterus or tissue sampling of the placenta. Sequenom's proprietary Fetal Nucleic Acid Technology, currently being developed, may be applicable to a range of non-invasive prenatal tests that use a mother's blood sample for fetal genetic screening. Sequenom's technology, based in part on the foundational research of Professors Dennis Lo and James Wainscoat while at the University of Oxford, isolates and analyses circulating fetal nucleic acid from a maternal blood sample.
In the opinion of Dr. Kenneth Moise, Professor of Obstetrics and Gynaecology and a specialist in Maternal-Fetal Medicine at Baylor College of Medicine in Houston, Texas, this is a major research breakthrough in prenatal medicine.
"This is potentially one of the biggest steps forward to determine genetic conditions in the foetus. The ability to make an early diagnosis is the key that opens the door for the future treatment of many birth defects before the child is born," says Dr. Moise. "This shows promise as an excellent alternative to amniocentesis and may give expectant parents peace of mind."
Through technology licensing agreements with clinical laboratories, Sequenom expects a non-invasive application of its technology for fetal Rhesus D (RhD) typing to become available in these laboratories beginning in the first half of 2007. Rhesus disease can occur when the blood of the expectant mother is incompatible with her unborn child. According to the Centers for Disease Control and Prevention (CDC), the incidence of haemolytic disease caused by RhD incompatibility in newborns occurs in approximately 1 in 1,000 live born infants. Complications from RhD disease can lead to jaundice, anaemia, brain damage, heart failure, and death.
"We are making significant progress in developing our proprietary Fetal Nucleic Acid Technology and anticipate applying our novel approach to multiple prenatal tests such as tests for RhD, cystic fibrosis, Down syndrome, and others," said Dr. Harry Stylli, Sequenom President and Chief Executive Officer. "We believe our technology has great potential to substantially improve the standard of care for all pregnant mothers."