Ring Chromosome 15

Ring chromosome 15 (RC15) can be detected using cell-based karyotyping and fluorescence in situ hybridization (FISH) test to determine its structure and dynamic mosaicism and further characterized by DNA-based chromosome microarray analysis (CMA) or next-generation sequencing (NGS) to delineate its genomic imbalances. More than 100 cases of RC15 have been described in the literature. Patients with RC15 showed craniofacial dysmorphisms, intellectual disability, growth retardation, malformations in heart and limbs, skin pigmentation, and reproduction problems. Male patients of RC15 are usually infertile or subfertile with genital anomalies. Female patients of RC15 usually present normal sexual development and gonadal function with different reproduction outcomes. Most cases of RC15 occur de novo except for five cases of maternal and one case of paternal transmission of a RC15. Genomic imbalances in the RC15 provide more reliable clinic-cytogenomic correlations from candidate genes in the critical regions. A multidimensional clinical evaluation on neurology, cardiac, dermatology, orthopedics, ophthalmology, and fertility should be considered for patients with RC15.