title: [A case of pseudoisodicentric chromosome 18q detected at prenatal diagnosis].
abstract: Although trisomy 18 (Edwards' syndrome) or the terminal deletion syndromes of 18p and 18q have been occasionally detected, pseudoisodicentric chromosome 18 is a very rare constitutional chromosomal abnormality. We describe a case of pseudoisodicentric chromosome 18q without mosaicism, which was confirmed from fetal cells in the amniotic fluid used for prenatal diagnosis of multiple congenital anomalies. A 23-yr-old pregnant woman was suspected of having a fetal anomaly at 18(+3) weeks gestation. In sonography, the fetus showed multiple anomalies: bilateral overt ventriculomegaly in the brain, ventricular septal defect and valve anomaly in the heart, bilateral club foot, polydactyly, meningocele, and a single umbilical artery. The pregnancy was terminated and a conventional G-banded chromosome study was performed using amniotic fluid. Twenty metaphase cells among the cultured amniocytes showed a 46,XX,psu idic(18)(q22). Consequently, the fetus had partial trisomy (18pter-->q22) and partial monosomy (18q22-->qter). Both parents were confirmed to have a normal karyotype.
authors.affiliation: Department of Laboratory Medicine, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Cho
authors.forename: Gayoung
authors.initials: G
authors.lastname: Lim
authors.forename: So Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Min Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Kyung A
authors.initials: KA
authors.lastname: Lee
authors.forename: Jong Rak
authors.initials: JR
authors.lastname: Choi
authors.forename: Hee Joo
authors.initials: HJ
authors.lastname: Lee
authors.forename: Jin Tae
authors.initials: JT
authors.lastname: Suh
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Park
authors.forename: Eui
authors.initials: E
authors.lastname: Jung
mesh_terms: D000015:Abnormalities, Multiple / Q000175:diagnosis / Q000235:genetics*; D002503:Centromere; D002887:Chromosomes, Human, Pair 18; D005260:Female; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D014314:Trisomy; D016216:Ultrasonography, Prenatal; D055815:Young Adult