Ying Chen1,2, Yiqian Liu3, Benjing Wang4, Jun Mao1,5, Ting Wang6, Kan Ye7, Yanlin Ye7, David S Cram3, Hong Li6. 1. Central Lab, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, Jiangsu, China. 2. Nanjing Medical University Affiliated Wuxi Maternity and Child Health Care Hospital, Wuxi, Jiangsu, China. 3. Berry Genomics Corporation, Beijing, China. 4. Gynecology Department, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, Jiangsu, China. 5. Obstetrics Department, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, Jiangsu, China. 6. Center for Reproduction and Genetics, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, Jiangsu, China. 7. Child Health Care Department, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, Jiangsu, China.
Abstract
OBJECTIVE: Inherited non-syndromic hearing loss (NSHL) is a common sensory disorder that afflicts otherwise healthy individuals. The aim of the study was to evaluate the performance of circulating single molecule amplification and re-sequencing technology (cSMART) for non-invasive prenatal testing (NIPT) of NSHL. METHOD: Neonatal inheritance of NSHL mutations was determined from bloodspots using SNaPshot genotyping. NIPT of cell-free DNA for fetal NSHL mutations in the GJB2, GJB3 and SLC26A4 genes was performed by a multiplex cSMART assay. The percentage of mutant alleles was used to deduce fetal DNA fractions and assign fetal genotypes. RESULTS: A total of 25 plasma samples selected with different fetal NSHL genotypes were coded and retrospectively analyzed by NIPT. Three normal fetuses, 18 carrier fetuses comprising seven GJB2 109G>A, four GBJ2 235delC, three GJB2 299-300delAT and four SLC26A4 IVS7-2A>G heterozygotes and four affected fetuses comprising two GJB2 109G>A homozygotes, one GBJ2 235delC homozygote and one compound GJB2 235delC/299-300delAT heterozygote were identified. All 25 fetal genotypes determined by the cSMART assay were concordant with neonatal genotypes. CONCLUSION: The cSMART assay applied to cell-free DNA isolated from maternal plasma of pregnant women is highly accurate for calling correct fetal NSHL genotypes.
OBJECTIVE: Inherited non-syndromic hearing loss (NSHL) is a common sensory disorder that afflicts otherwise healthy individuals. The aim of the study was to evaluate the performance of circulating single molecule amplification and re-sequencing technology (cSMART) for non-invasive prenatal testing (NIPT) of NSHL. METHOD: Neonatal inheritance of NSHL mutations was determined from bloodspots using SNaPshot genotyping. NIPT of cell-free DNA for fetal NSHL mutations in the GJB2, GJB3 and SLC26A4 genes was performed by a multiplex cSMART assay. The percentage of mutant alleles was used to deduce fetal DNA fractions and assign fetal genotypes. RESULTS: A total of 25 plasma samples selected with different fetal NSHL genotypes were coded and retrospectively analyzed by NIPT. Three normal fetuses, 18 carrier fetuses comprising seven GJB2 109G>A, four GBJ2 235delC, three GJB2299-300delAT and four SLC26A4 IVS7-2A>G heterozygotes and four affected fetuses comprising two GJB2 109G>A homozygotes, one GBJ2 235delC homozygote and one compound GJB2235delC/299-300delAT heterozygote were identified. All 25 fetal genotypes determined by the cSMART assay were concordant with neonatal genotypes. CONCLUSION: The cSMART assay applied to cell-free DNA isolated from maternal plasma of pregnant women is highly accurate for calling correct fetal NSHL genotypes.