All-in-One Whole-Exome Sequencing Strategy for Fetal Anomaly Diagnosis

A new strategy that combines various sequencing data analyses for the prenatal diagnosis of fetuses with ultrasound abnormalities with no apparent genetic cause is reported in Prenatal Diagnosis this week. Currently, fetuses with ultrasound anomalies for which no genetic cause is identified via PCR or microarray analysis may then undergo exome analysis, though that is largely limited to single nucleotide variant (SNV) analysis. This approach, though, leads to a delay in reporting time. But simultaneously performing microarray and exome sequencing leads to additional costs. A team led by scientists from Radboud University has instead developed an all-in-one approach that simultaneously analyzes SNVs, copy number variants, and copy-number-neutral absence-of-heterozygosity from one set of whole-exome sequencing data to identify the most commonly occurring aneuploidies. In a one-year evaluation of the strategy in 415 prenatal samples, the research group shows that it is efficient in terms of reporting time, with genetic analyses being completed within two weeks of sampling, which also improved genetic counseling time. The approach is also cost-effective, they write, "as additional tests such as microarray and contamination tests on both maternal and fetal DNA are avoided.