Prenatal diagnosis and molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome derived from chromosome 21q11.2-q21.1 and a literature review

• Main Authors: Chih-Ping Chen (Author), Ming Chen (Author), Chia-Hsun Wu (Author), Chen-Ju Lin (Author), Schu-Rern Chern (Author), Peih-Shan Wu (Author), Yen-Ni Chen (Author), Shin-Wen Chen (Author), Shun-Ping Chang (Author), Li-Feng Chen (Author), Wayseen Wang (Author)
• Format: Book
• Published: Elsevier, 2017-08-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Objective: We present prenatal diagnosis and molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome (sSMC) derived from chromosome 21q11.2-q21.1, and we review the literature of an sSMC(21) with a duplication of 21q11.2-q21.1. Case report: A 40-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 47,XX,+mar [18]/46,XX [4]. The parental karyotypes were normal. Prenatal ultrasound findings were unremarkable. aCGH analysis of cultured amniocytes revealed a 2.855-Mb duplication of 21q11.2-q21.1 encompassing the genes of LIPI, ABCC13 and NRIP1. Metaphase fluorescence in situ hybridization analysis on cultured amniocytes revealed a result of 47,XX,+mar .ish der(13/21) (D13/21Z1+) [10]. Spectral karyotyping analysis determined the origin of chromosome 21 in the sSMC. A female fetus was delivered with no phenotypic features of Down syndrome and no structural abnormalities. We discuss the genotype-phenotype correlation of LIPI, ABCC13 and NRIP1, and review the literature of an sSMC(21) associated with dup(21)(q11.2q21.1). Conclusion: aCGH is useful for identification of the nature and genetic component of a prenatally detected sSMC.

Item Description

1028-4559
10.1016/j.tjog.2017.06.004