Prenatal diagnosis of partial trisomy 3q resulting from t(3;14) in a fetus with multiple anomalies including vermian hypoplasia.

While genetic origin of Dandy-Walker complex has not yet fully elucidated, the complex has been known to be associated with structural and chromosomal abnormalities. A partial trisomy 3q was also identified in patients with DWC. 3q duplication syndrome is defined as duplications of large parts of 3q, especially 3q21-qter. Most cases with 3q duplication are diagnosed postnatally and the patients show typical features including various facial dysmorphisms, congenital heart defects, genitourinary malformations, and mental and growth retardation. Here we report a 28 year old nulliparous woman who was referred from the infertility clinic at 21 gestational weeks. Fetal ultrasonographic examination showed various abnormal findings including a ventricular septal defect, hydrocephalus, and hypoplasia of the cerebellar vermis. Fetal chromosome analysis was initially reported as 46,XY,der(14)(?::p11.2→qter). Array CGH followed by FISH allowed precise characterization of the der(14) chromosome and the initial karyotype of the fetus had been changed to 46,XY,add(14)(p11).ish der(14)t(3;14)(q26.1;p11)(tel3q+).arr 3q26.1q29(166249469-199288361)x3. Though further studies are required, gene clusters rather than a single gene might be responsible for the clinical features of the Dandy-Walker complex.