August 18, 2008

Signature Genomic Laboroatories Reports Diagnostic Yield of Microarray Technology in Prenatal and Neonatal Specimens

Researchers at Signature Genomic Laboratories recently published the first large-scale prospective study comparing the detection rate of chromosomal abnormalities--missing or extra pieces of DNA--by microarray analysis in prenatal cases to that of neonatal cases referred with a variety of clinical findings, including congenital anomalies.

In the study, the findings of which will appear in the September issue of the journal Prenatal Diagnosis and were electronically published July 22, microarray analysis was performed on 151 prenatal specimens and 1375 postnatal specimens less than 3 months of age using the PrenatalChip(R) or SignatureChip(R) microarray, respectively. A clinically significant chromosome abnormality was detected in 11.4% of the neonates that had previous normal chromosome analysis or no chromosome analysis performed. In the prenatal population, abnormalities were detected in 1.3% of cases. However, the authors suggested this detection rate may be the result of an ascertainment bias because all prenatal cases had previous normal chromosome analysis, whereas only 12% of neonates had a previous normal chromosome analysis. In addition, almost half of the neonatal population was referred for dysmorphic features, a clinical indication unlikely to be identified in the prenatal population.

"Our results demonstrate the detection rate of causative chromosome abnormalities in infants with birth defects of unknown cause is more than three times that routine chromosome analysis, which is the current standard diagnostic tool," said Dr. Lisa G. Shaffer, Ph.D., President and CEO of Signature and lead author of the study. "In addition, although we detected chromosome abnormalities in only 1.3% of prenatal cases, the majority of abnormalities in the neonates would not have been identified by routine chromosome analysis, suggesting that widespread use of microarary analysis for prenatal diagnosis would yield higher detection rates than routine karyotyping."

About Signature Genomic Laboratories

Signature Genomic Laboratories, founded in 2003, was the first laboratory to provide microarray-based cytogenetic diagnostics with its proprietary SignatureChip(R) and is the leader in providing microarray-based chromosome analysis. Signature's worldwide client base includes clinical geneticists, neurologists, pediatricians, neonatologists, obstetricians, and the research community. Signature is CAP accredited, CLIA certified, and has clinical licenses from California, Rhode Island and Florida. Additional information about Signature Genomic Laboratories is available at