Ring chromosome 6 syndrome is a rare chromosomal anomaly syndrome with highly variable phenotype principally characterized by prenatal/postnatal growth failure, intellectual disability, developmental delay, craniofacial dysmorphism (incl. microcephaly, microphthalmia, epicanthus, low-set and malformed ears, broad and flat nasal bridge, full lips, micrognathia), central nervous system anomalies (e.g. hydrocephalus, cortical atrophy, ventriculomegaly), short neck, and delayed bone age. Cardiac defects, limb anomalies, hip joint malformations, and seizures have also been reported.

Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation.