Ring chromosome 5 syndrome

Ring chromosome 5 syndrome (also known as ring 5, r(5) syndrome) is an extremely rare chromosomal disorder in which the two ends of chromosome 5 break and rejoin to form a circular or ring-shaped structure. This rearrangement typically results in the loss of genetic material from one or both ends (terminal deletions) of chromosome 5, and the clinical severity depends largely on the amount of chromosomal material lost. The ring chromosome may also exhibit instability during cell division, leading to mosaicism with cells that have lost the ring or contain duplicated rings, further contributing to phenotypic variability. Clinical features commonly reported in individuals with ring chromosome 5 include intrauterine and postnatal growth retardation, intellectual disability of variable severity, microcephaly, and distinctive craniofacial features such as a flat nasal bridge, micrognathia, low-set ears, and hypertelorism. Additional findings may include feeding difficulties in infancy, seizures, skeletal anomalies, and congenital heart defects. Some patients may also exhibit features overlapping with Cri-du-chat syndrome (5p deletion syndrome) if significant material from the short arm of chromosome 5 is lost, including a high-pitched cry in infancy. There is no specific cure or targeted therapy for ring chromosome 5 syndrome. Management is supportive and symptomatic, involving a multidisciplinary team that may include pediatricians, neurologists, cardiologists, and developmental specialists. Early intervention programs, speech therapy, physical therapy, and special education services are important components of care. Genetic counseling is recommended for affected families to discuss recurrence risk and the nature of the chromosomal rearrangement.

Common questions about Ring chromosome 5 syndrome