Prenatal diagnosis of a 4q33-4qter deletion in a fetus with hydrops

Objective: The 4q- syndrome comprises all microscopically visible deletions of the long arm of chromosome 4. Cases with 4q deletions represent a diverse group that share several phenotypic characteristics. We report the prenatal diagnosis of an isolated terminal 4q33 deletion in a fetus with hydrops. Method: A comprehensive workup, including an amniocentesis, was performed on a 32-week fetus presenting with massive hydrops and polyhydramnios. Results: The karyotype obtained from the amniotic fluid showed an unusual banding pattern on chromosome 4q. Fluorescent in situ hybridization revealed a 4q33-qter deletion. The proband shared several of the phenotypic characteristics of the 4q- syndrome. Multidisciplinary evaluation of the newborn confirmed the genotype and failed to identify another cause for the hydrops. Conclusion: We suggest that the broad spectrum of phenotypes expressed by patients with terminal 4q33 deletions includes hydrops fetalis.