Table 2

Recurrent interstitial microdeletion/duplications associated with mental retardation

NameSize (Mb)*LCRMIMClinical features
1q21.1 microdeletion1.1+612474Mild-to-moderate MR, MC, cardiac abnormalities, cataracts, clear incomplete penetrance
1q21.1 microduplication1.1+612475Autism or autistic behaviours, mild to moderate MR, microcephaly, mild FD
1q41q42 microdeletion1.2MR, seizures, various dysmorphisms, cleft palate, diaphragmatic hernia
2p15q16.1 microdeletion3.9MR, 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 microdeletion1.6+609425MR, mild FD, including high nasal bridge and short philtrum
3q29 microduplication1.6+611936Mild/moderate MR, MC, obesity
7q11.23 microduplication1.5+609757MR, speech and language delay, autism spectrum disorders, mild FD
9q22.3 microdeletion6.5MR, hyperactivity, overgrowth, trigonocephaly, macrocephaly, FD
12q14 microdeletion3.4Mild MR, failure to thrive, proportionate short stature and osteopoikilosis
14q11.2 microdeletion0.4MR, 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 microdeletion1.5+612001MR, epilepsy, hypotonia, short stature, microcephaly and cardiac defects
15q24 microdeletion1.7+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/duplication0.6+611913Association with MR, autism, schizophrenia
16p11.2p12.2 microdeletion7.1+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 microduplication1.6+Association with autism, significance uncertain
16p13.1 microdeletion1.6+MR, MC, epilepsy, short stature, phenotypic variability
17p11.2 microduplication 3.7+610883MR, infantile hypotonia, failure to thrive, autistic features, sleep apnoea, and structural cardiovascular anomalies
17q21.31 microdeletion0.5+610443MR, 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 microdeletion0.7MR, pre- and postnatal growth retardation, primary microcephaly, hypospadias, ectodermal dysplasia including scalp aplasia, dysplastic nails and dry skin
22q11.2 microduplication3.7+608363Highly variable. MR, FD, for example widely spaced eyes and downslanting palpebral fissures, velopharyngeal insufficiency, conotruncal heart disease
22q11.2 distal microdeletion1.4–2.1+611867MR, 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 microduplication0.4–0.8MR, severe hypotonia, progressive lower limb spasticity, absent or very limited speech
  • FD, facial dysmorphisms; LCR, low copy repeat; MC, microcephaly; MR, mental retardation.

  • * Common region.

  • Potocki–Lupski syndrome.