Variations of the signs and symptoms occur depending upon the area of chromosome 13 that is deleted.<unk> s from the centromere to<unk> 32 or any<unk> s including the<unk> 32 band are associated with slow growth, intellectual disability, and congenital malformations.<unk> s from<unk> 33 to the end of the chromosome are associated with intellectual disability. Intellectual disabilities range from very mild to very severe, and can co-occur with behavioral disorders and/or autism spectrum disorders. At birth, the main symptoms include low weight (due to intrauterine growth restriction), hypotonia, and feeding difficulties. Infants may also have cleft palate.<unk>  gives a characteristic appearance to affected individuals, potentially including microphthalmia (small eyes), hypertelorism (wide-set eyes), thin forehead, high palate, underdeveloped midface, small mouth, small nose, broad, flat nasal bridge, short neck, low hairline, irregular or wrongly positioned teeth, low-set ears, micrognathia (small jaw), tooth enamel defects, short stature, microcephaly (small head), a prominent, long philtrum, and earlobes turned inwards. Congenital heart disease is also associated with<unk> . Common defects include atrial septal defect, tetralogy of Fallot, ventricular septal defect, patent ductus arteriosus, pulmonary stenosis, and coarctation of the aorta. Defects of the endocrine system, digestive system, and genitourinary system are also common. These include underdevelopment or agenesis of the pancreas, adrenal glands, thymus, gallbladder, and thyroid; Hirschsprung's disease; gastric reflux, imperforate anus, retention testis, ectopic kidney, renal agenesis, and hydronephrosis. A variety of brain abnormalities are also associated with<unk><unk> . They can include epilepsy, craniosynostosis (premature closing of the skull bones), spastic diplegia, cerebral hypotrophy, underdevelopment or agenesis of the corpus callosum, cerebellar hypoplasia, deafness, and, rarely, hydrocephalus, Dandy–Walker syndrome, and spina bifida. The eyes can be severely damaged and affected individuals may be blind. They may also have coloboma of the iris or choroid, strabismus, nystagmus, glaucoma, or cataracts. Other skeletal malformations are found with<unk> , including syndactyly, clubfoot, clinodactyly, and malformations of the vertebrae and/or thumbs.<unk> s that include the<unk> 32 band, which contains the brain development gene ZIC2, are associated with holoprosencephaly; they are also associated with hand and foot malformations.<unk> s that include the<unk> 14 band, which contains the tumor suppressor gene Rb, are associated with a higher risk of developing retinoblastoma, which is more common in XY children.<unk>  of the<unk> 33.3 band is associated with hypospadias. Other genes in the potentially affected region include NUFIP1, HTR2A, PDCH8, and PCDH17. In males with<unk> , genital abnormalities are common. The meatus, or urinary opening, may appear on the underside of the penis (hypospadis), and/or the testes will not descend into the scrotum (cryptochidism). The scrotum will often be unusually small or abnormally divided into two sections (bifid scrotum); the penis may be unusually small (micropenis), and/or abnormal passage may be present between the scrotum and the anus (perineal fistula). In rare cases, the anal opening may be absent or covered by a thing membrane which can cause obstruction (anal atresia).
13q deletion syndrome
22q13 deletion syndrome
2q37 deletion syndrome
9q34 deletion syndrome
22q11.2 distal deletion syndrome
1q21.1 deletion syndrome
Chromosome 5q deletion syndrome
1p36 deletion syndrome