<unk> , also known as ring<unk> , is a rare chromosomal disorder. Ring chromosomes occur when the ends of a chromosome lose material and fuse into a ring shape; in the case of ring<unk> , this occurs for chromosome<unk> , the last numbered human autosome.<unk>  is marked by a number of consistent traits, such as intellectual disability, speech delay, hypotonia, and hyperactivity. The condition has a similar phenotype to Phelan-McDermid syndrome, as the loss of the SHANK3 gene is implicated in both.
Ring chromosome 22
Ring chromosome 15
Ring chromosome 18
X chromosome
Y chromosome
Dup15q
Distal 18q-
Ethosome