Prenatal Diagnosis of Small Supernumerary Marker Chromosome 10 by Array-Based Comparative Genomic Hybridization and Microdissected Chromosome Sequencing.

Interpreting the clinical significance of small supernumerary marker chromosomes (sSMCs) in prenatal diagnosis is still an urgent problem in genetic counselling regarding the fate of a pregnancy. We present a case of prenatal diagnosis of mosaic sSMC(10) in a foetus with a normal phenotype. Comprehensive cytogenomic analyses by array-based comparative genomic hybridization (aCGH), sSMC microdissection with next-generation sequencing (NGS) of microdissected library, fluorescence in situ hybridization (FISH) with locus-specific and telomere-specific DNA probes and quantitative real-time PCR revealed that sSMC(10) had a ring structure and was derived from the pericentromeric region of chromosome 10 with involvement of the 10p11.