Table 1.

Cytogenetic and molecular findings in patients with ring chromosomes.

Ring chr	Absolute size, Mb	Age/sex	Main phenotype features	Genome imbalance
8	147.6	1.4/male	Neuropsychological developmental delay; muscle hypotonia; microcephaly; anomalies of the face, hands, and feet	invdup8p23.1-p11.22, del8p23.3-p23.1
13	113.6	17/male	Neuropsychic and speech delay, anxiety, macrocephaly, microorchidism, multiple anomalies of the internal organs	del13q34
18	63.2	3/male	Delayed psychomotor and speech development, bilateral ptosis of the eyelids, tooth abnormalities, hypermobility of the joints and violations of skin pigmentation	del18p11.32-p11.21, del18q23
22	49.2	6/female	Delayed psychomotor and speech development, hyperactivity, sleep disorders, multiple developmental anomalies, Phelan–McDermid syndrome	dup22q13.32, del22q13.32-q13.33