Telomer-structure Chr<unk>  The syndrome is caused by the loss of genetic material near the end of the long arm (q) of chromosome<unk>  . The break that causes the telomere(s) to be lost occurs near the end of the chromosome, and is called a constitutional ring. These rings arise spontaneously ( it is rarely inherited). The genetic abnormality occurs randomly in sperm or egg cells or it may occur in early embryonic growth, if it occurs during embryonic growth the ring chromosome may be present in only some of a person's cells.
Ring chromosome 14 syndrome
Ring chromosome 20 syndrome
Smith Martin Dodd syndrome
Kaufman oculocerebrofacial syndrome
13q deletion syndrome
2q37 deletion syndrome
22q11.2 duplication syndrome
8p23.1 duplication syndrome