Recurrent interstitial microdeletion/duplications associated with mental retardation
| Name | Size (Mb)* | LCR | MIM | Clinical features |
| 1q21.1 microdeletion | 1.1 | + | 612474 | Mild-to-moderate MR, MC, cardiac abnormalities, cataracts, clear incomplete penetrance |
| 1q21.1 microduplication | 1.1 | + | 612475 | Autism or autistic behaviours, mild to moderate MR, microcephaly, mild FD |
| 1q41q42 microdeletion | 1.2 | − | − | MR, seizures, various dysmorphisms, cleft palate, diaphragmatic hernia |
| 2p15q16.1 microdeletion | 3.9 | − | − | MR, MC, receding forehead, ptosis, telecanthus, short palpebral fissures, downslanting palpebral fissures, broad/high nasal bridge, long/straight eyelashes, smooth and long philtrum, smooth upper vermillion border, everted lower lip, high narrow palate, hydronephrosis, optic nerve hypoplasia |
| 3q29 microdeletion | 1.6 | + | 609425 | MR, mild FD, including high nasal bridge and short philtrum |
| 3q29 microduplication | 1.6 | + | 611936 | Mild/moderate MR, MC, obesity |
| 7q11.23 microduplication | 1.5 | + | 609757 | MR, speech and language delay, autism spectrum disorders, mild FD |
| 9q22.3 microdeletion | 6.5 | − | − | MR, hyperactivity, overgrowth, trigonocephaly, macrocephaly, FD |
| 12q14 microdeletion | 3.4 | − | − | Mild MR, failure to thrive, proportionate short stature and osteopoikilosis |
| 14q11.2 microdeletion | 0.4 | − | − | MR, widely spaced eyes, short nose with flat nasal bridge, long philtrum, Cupid's bow of the upper lip, full lower lip, auricular anomalies |
| 15q13.3 microdeletion | 1.5 | + | 612001 | MR, epilepsy, hypotonia, short stature, microcephaly and cardiac defects |
| 15q24 microdeletion | 1.7 | + | − | MR, growth retardation, MC, digital abnormalities, genital abnormalities, hypospadias, loose connective tissue, high frontal hairline, broad medial eyebrows, downslanted palpebral fissures, long philtrum |
| 16p11.2 microdeletion/duplication | 0.6 | + | 611913 | Association with MR, autism, schizophrenia |
| 16p11.2p12.2 microdeletion | 7.1 | + | − | MR, flat facies, downslanting palpebral fissures, low-set and malformed ears, eye anomalies, orofacial clefting, heart defects, frequent ear infections, short stature, minor hand and foot anomalies, feeding difficulties, hypotonia |
| 16p13.1 microduplication | 1.6 | + | − | Association with autism, significance uncertain |
| 16p13.1 microdeletion | 1.6 | + | − | MR, MC, epilepsy, short stature, phenotypic variability |
| 17p11.2 microduplication † | 3.7 | + | 610883 | MR, infantile hypotonia, failure to thrive, autistic features, sleep apnoea, and structural cardiovascular anomalies |
| 17q21.31 microdeletion | 0.5 | + | 610443 | MR, hypotonia, long hypotonic face with ptosis, large and low set ears, tubular or pear shaped nose with bulbous nasal tip, long columella with hypoplastic alae nasi, broad chin |
| 19q13.11 microdeletion | 0.7 | − | − | MR, pre- and postnatal growth retardation, primary microcephaly, hypospadias, ectodermal dysplasia including scalp aplasia, dysplastic nails and dry skin |
| 22q11.2 microduplication | 3.7 | + | 608363 | Highly variable. MR, FD, for example widely spaced eyes and downslanting palpebral fissures, velopharyngeal insufficiency, conotruncal heart disease |
| 22q11.2 distal microdeletion | 1.4–2.1 | + | 611867 | MR, prematurity, prenatal/postnatal growth delay, mild skeletal abnormalities, arched eyebrows, deep set eyes, smooth philtrum, thin upper lip, hypoplastic alae nasi, small pointed chin |
| Xq28 microduplication | 0.4–0.8 | − | − | MR, severe hypotonia, progressive lower limb spasticity, absent or very limited speech |