Ring Chromosome 16

Ring chromosome 16 (RC16) is an ultra-rare chromosomal structural abnormality with only eight cases reported in the literature. Included in this case series are those eight published cases, plus our unpublished case, for a total of 9 cases involving RC16. It was found in this case series that deletions of variable sizes of the short arm of RC16 correlated well with clinical features, and deletions of the long arm of RC16 were not associated with any specific disorder or syndrome. The different sizes and forms of RC16 and ring instability, as well as a limited number of documented cases, all contribute to the challenge of making precise clinico-cytogenomic correlations for patients of RC16.