Monosomy 5p, also known as Cri du chat syndrome, is a rare autosomal deletion syndrome characterized by a mewing cry (cri du chat) in infancy, multiple congenital anomalies, intellectual disability, microcephaly, and facial dysmorphism.

Fetal choroid plexus cysts (CPCs) are sonographically discrete, small cysts found in the choroid plexus within the lateral cerebral ventricles of the developing fetus at 14 to 24 weeks gestation. Imaging of the choroid plexus is performed in the transverse plane of the fetal head at the same level that the lateral cerebral ventricle is evaluated. The choroid plexus should be inspected bilaterally for the presence of cysts. The size of CPCs is not of clinical relevance (pmid:16100637).