In recent years, prenatal detection of fetal congenital anomalies
has become increasingly more frequent, due to the adoption of routine
ultrasound imaging. Simultaneously, advanced genetic testing has
evolved demonstrating that an increasing proportion of these anomalies
have a genetic cause.
Approximately 10 years ago, chromosomal microarray
analysis (CMA) was added to standard karyotyping as a prenatal
diagnostic test increasing the detection rate of clinically significant
cytogenetic abnormalities by 6% in cases with a single anomaly
(abnormality) and 13% when multiple anomalies were present.
‘Fetal genomic sequencing will increase the detection rate of genetic findings and this information will significantly improve patient counseling and neonatal treatment.’
words, CMA looked at cell and chromosomal disorders. These prior
studies, including a multi-center Eunice Kennedy Shriver National
Institutes Child Health and Human Development (NICHD)-funded trial
presented at a prior Society of Maternal-Fetal Medicine annual meeting,
has changed national guidelines so that CMA is now the recommended test
for evaluating fetal anomalies.
While CMA has been a significant improvement, an estimated 60-70% of
cases with identified fetal abnormalities still remain without a
genetic diagnosis.In a study to be presented in the oral plenary
session the Society for Maternal-Fetal Medicine's
annual meeting, The Pregnancy Meeting, researchers with the Columbia
University Medical Center in New York found that, in preliminary data,
fetal genomic (whole exome) sequencing (WES) as a diagnostic test for
women with pregnancies complicated by major fetal congenital anomalies
increased the detection rate of genetic findings by between 10 to 30%.
The study, titled Whole exome sequencing in the evaluation of fetal
structural anomalies: A prospective study of sequential patients used
selected patients that were felt to have a high likelihood of having a
fetal genetic anomaly.
With this current study, fetal genomic (whole exome)
sequencing was evaluated as a diagnostic test for women with
pregnancies complicated by major fetal congenital anomalies.
"Our preliminary data and published literature indicate that
sequencing will increase the detection rate of genetic findings and this
information will significantly improve patient counseling and neonatal
treatment," explained Ronald Wapner, professor of obstetrics and
gynecology for the maternal fetal medicine department at Columbia
University Medical Center, who is presenting the study.
associations with genes with very specific fetal phenotypes are also
beginning to be uncovered," he added.