Prenatal diagnosis of fetal ring chromosome 18 with deletion: a case report

We hereby reported a case of ring chromosome 18 complicated by the deletion of 18p11.32p11.31 and 18q21.33q23 diagnosed prenatally by G-banding karyotype and chromosomal microarray analysis (CMA). Ultrasound scan indicated a single umbilical artery and intrauterine growth retardation at the second trimester. The result of G-banding karyotyping was 46, XN, r(18)(p11.3q21.3) and CMA indicated that there was a 3.3 Mb deletion at 18p11.32p11.31 and a 16.9 Mb deletion at 18q21.33q23. All these suggested that the fetus might present with clinical manifestations such as growth retardation, epilepsy, speech delay and growth hormone deficiency after birth, so the couple decided to terminate the pregnancy after genetic counseling. Key words: Chromosomes, human, pair 18; Ring chromosomes; Chromosome deletion; Prenatal diagnosis