Recognised symptoms are: * Only one set of genes on the two chromosomes function (haploinsufficiency) * Thrombocytopenia-absent radius (TAR syndrome), in case of a class II-deletion * Neurological-psychiatric problems: schizophrenia; epilepsy; learning problems; cognitive disabilities — mild to moderate; developmental delay — mild to moderate (milestones like sitting, standing and walking; come at a later period in childhood); children show an ataxic gait and fall down a lot * Dysmorphism: slightly unusual facial appearance; disturbed growth; skeletal malformations; small head (microcephaly); prominent forehead; bulbous nose; deep-set eyes; broad thumbs; broad toes; squint; very flexible joints; clavicular pseudoarthrosis (the collarbone doesn't develop normally) (class II-deletion); an extra transverse crease of the fifth finger (class II-deletion)); problems with the development of the vagina (Müllerian aplasia) * Eyes: cataracts * Heart abnormalities and cardiovascular anomalies (30% of the cases): anomalous origin of the coronary artery (Class II-deletion) * Kidneys: missing kidney or floating kidneys * Cancer: neuroblastoma * Sleep disturbances It is not clear whether the list of symptoms is complete. Very little information is known about the syndrome. The syndrome can have completely different effects on members of the same family. A common deletion is between 1.0–1.9Mb. Mefford states that the standard for a deletion is 1.35Mb. The largest deletion seen on a living human is over 5 Mb.
1q21.1 deletion syndrome
13q deletion syndrome
22q13 deletion syndrome
2q37 deletion syndrome
22q11.2 distal deletion syndrome
9q34 deletion syndrome
1p36 deletion syndrome
Chromosome 5q deletion syndrome