Rainbow Genomics Launches Rapid Trio Whole Genome Sequencing for Pregnancy Cases with Prenatal Ultrasound Abnormalities

High diagnostic yield delivered by trio whole genome sequencing coupled with a one-week turnaround time provides physicians with a timely diagnosis.

HONG KONG and SAN FRANCISCO

March 9, 2020

Hong Kong-based Rainbow Genomics launches a trio whole genome sequencing test for pregnancy cases with congenital abnormalities indicated by prenatal ultrasound. The test is designed to “rapidly” determine genetic etiologies associated with anomalies visualized on ultrasound during the second trimester, where traditional prenatal testing failed to provide a diagnosis.

Abnormal fetal ultrasound is detected in approximately 3% of pregnancies. Genetic testing with chromosomal microarray (CMA) and karyotyping are routinely used as a first-line approach, with a diagnostic yield of only 6%-10%. Consequently, the majority of the families affected failed to receive a definitive clinical result.

Whole genome sequencing test provides relative high diagnostic yields, ranging from 30% -80% in reported pregnancy cases. The technology offers sufficient resolution to enable the reporting of copy number and structural, exon-wide deletion and insertion variants, as well as duplication and single nucleotide variants. The use of trio analysis further allows for prioritization of review of de novo and compound heterozygous variants that have an increased likelihood of being pathogenic. Coupled with a one-week turnaround time, physicians can now choose to apply the test during the second trimester of a pregnancy.

Rainbow Genomics is working with a group of experienced fetal specialists in Hong Kong to deliver the test. Amniocentesis or chorionic villus sampling is performed at their offices. Trio whole genome sequencing of the fetus and both parents, is processed at a U.S. CAP-accredited and CLIA-certified laboratory. Simultaneous clinical interpretation is provided by Rainbow’s teams of medical and clinical genetics experts in Hong Kong, U.S. and Japan. Clinical report is issued by a board-certified and licensed medical director in Japan. The turnaround time for this test is approximately one week.

In addition to genome-wide analysis of genetic variants associated with reported symptoms, a list of 600 genes associated with 100 potentially-debilitating, neonatal genetic disorders will be further analyzed to assure comprehensiveness of the clinical interpretation. Copy number and structural variation, duplication, exon-wide insertion and deletion variants, as well as small indels and single nucleotide variants are analyzed. Only gene variants with high penetrance and well-understood expressivity are reported.

“Approximately 3% of pregnancies shows abnormal sonograms indicating fetal structural anomalies. The result may be associated with a minor clinical issue, or a severe fatal disorder. However, routine genetic testing by microarray method only resolves 6%-10% of these cases,” Said Daniel Siu, CEO of Rainbow Genomics. “Trio whole genome sequencing provides a highly-sensitive approach to rapidly determine the genetic causes of the underlying disorders found in these pregnancies, especially for high-risk couples (e.g. with preexisting conditions) or families that had a previously-affected pregnancy (e.g. suspicion for a hereditary genetic cause)”

About Rainbow Genomics
Rainbow Genomics is committed to providing clinically-validated and affordable genetic tests to patients in
Hong Kong, Japan, Singapore and other Asian countries. The company delivers clinical interpretations
specifically for Asians, based on expert understanding of their genetics, and medical care experience in Hong
Kong, Japan, and the United States. Rainbow Genomics specializes in providing whole genome & whole exome sequencing,
pharmacogenomic, hereditary cancer and polygenic risk assessment tests to enable physicians to use genomic information for diagnosis, treatment, and disease prevention. Visit us at rainbowgenomics.com.