Prenatal diagnosis of isochromosome 20q in a fetus with vertebral anomaly and rocker-bottom feet

• Main Authors: Aline Receveur, Sophie Brisset, Jelena Martinovic, Anne Bazin, Laurence Lhomann, Claire Colmant, Dominique Pineau, Valérie Gautier, Lucie Tosca, Gérard Tachdjian
• Format: Article
• Language: English
• Published: Elsevier 2017-10-01
• Series: Taiwanese Journal of Obstetrics & Gynecology
• Subjects: Chromosomal microarray analysis; Isochromosome 20q; Uncultured and cultured amniotic fluid; Fetal malformations
• Online Access: http://www.sciencedirect.com/science/article/pii/S1028455917302073

Objective: Isochromosome of the long arm of chromosome 20 (i(20q)) is a rare structural abnormality in prenatal diagnosis. Thirty prenatal cases of mosaic i(20q) have been reported, among which only four are associated with fetal malformations. We describe a new prenatal case of i(20q) with fetal malformations. Materials and methods: We also observed a discrepancy between uncultured and cultured amniotic fluid cells by using conventional cytogenetic, fluorescence in situ hybridization and array-SNP analysis. Results: The short arm deletion of chromosome 20 arising from the isochromosome encompassed two candidate genes PAX1 and JAG1 involved in cranio-facial and vertebral development. Conclusion: The data would allow establishing a phenotype–genotype correlation. Thus, we proposed to define a recognizable syndrome combining cranio-facial dysmorphism, vertebral bodies' anomalies, feet and cerebral malformations.