Ring chromosome 7 syndrome

Ring chromosome 7 syndrome (also known as ring 7, r(7) syndrome) is an extremely rare chromosomal disorder in which the two ends of chromosome 7 fuse together to form a ring structure, typically resulting in the loss of genetic material from one or both ends of the chromosome. This structural rearrangement is classified under ICD-10 as Q93.2 (chromosome replaced with ring, dicentric, or isochromosome). The condition arises most often as a de novo (new) event and is not typically inherited from a parent. The clinical features of ring chromosome 7 syndrome are variable depending on the amount and location of deleted genetic material, as well as the degree of ring instability during cell division, which can lead to mosaicism. Commonly reported features include prenatal and postnatal growth retardation (short stature), intellectual disability of variable severity, microcephaly, and facial dysmorphism. Additional findings may include skin abnormalities such as café-au-lait spots or other pigmentary changes (potentially related to mosaic loss of the ring chromosome), skeletal anomalies, and developmental delay. Some patients have been reported with features overlapping with Russell-Silver syndrome when significant deletion of chromosome 7 material occurs, particularly involving imprinted regions. There is no specific cure or targeted therapy for ring chromosome 7 syndrome. Management is supportive and symptomatic, involving multidisciplinary care that may include growth hormone therapy for short stature, early intervention programs, speech and occupational therapy for developmental delays, and regular monitoring for associated complications. Genetic counseling is recommended for affected families to discuss recurrence risk and prognosis.

Common questions about Ring chromosome 7 syndrome