L1CAM mutations in three fetuses diagnosed by medical exome sequencing.

Objective: The L1 cell adhesion molecule (L1CAM) gene, encodes the L1 cell adhesion molecule, is involved in the central nervous system development. Its mutations result in L1 syndrome which is associated with brain malformation and nervous developmental delay.

Case Report: We presented three fetuses with hydrocephalus and agenesis of the corpus callosum detected by ultrasound, followed by medical exome sequencing (MES) test with L1CAM mutations: two known missense mutation c.

Secondary findings from non-invasive prenatal testing for common fetal aneuploidies by whole genome sequencing as a clinical service.

Objective: To report secondary or additional findings arising from introduction of non-invasive prenatal testing (NIPT) for aneuploidy by whole genome sequencing as a clinical service.

Methods: Five cases with secondary findings were reviewed.

Results: In Case 1, NIPT revealed a large duplication in chromosome 18p, which was supported by arrayCGH of amniocyte DNA, with final karyotype showing mosaic tetrasomy 18p.

Discordant results between fetal karyotyping and non-invasive prenatal testing by maternal plasma sequencing in a case of uniparental disomy 21 due to trisomic rescue.

Uniparental disomy (UPD) is an uncommon chromosome condition, but UPD involving chromosome 21 is rarely reported. We reported here a case who had first trimester screening test for Down syndrome, chorionic villus sampling for fetal karyotyping, quantitative fluorescence polymerase chain reaction (QF-PCR), as well as non-invasive prenatal testing (NIPT) by maternal plasma sequencing. There were discordant results between fetal karyotyping and NIPT due to UPD 21combined with confined placental mosaicism of trisomy 21.