Suspicion of a<unk>  abnormality is typically raised due to the presence of developmental delays or birth defects. Diagnosis of ring 18 is usually made via a blood sample. A routine<unk>  analysis, or karyotype, is usually used to make the initial diagnosis, although it may also be made by microarray analysis. Increasingly, microarray analysis is also being used to clarify breakpoints. Prenatal diagnosis is possible via amniocentesis or chorionic villus sampling.
Ring chromosome 18
Ring chromosome 15
Ring chromosome 22
X chromosome
Y chromosome
Dup15q
Distal 18q-
Ethosome