13q deletion syndrome | |
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Classification and external resources | |
DiseasesDB | 32696 |
13q deletion syndrome is a rare genetic disease caused by the deletion of some or all of the large arm of human chromosome 13. It causes intellectual disability and congenital malformations that affect a variety of organ systems.
Different areas of deletion are associated with different symptoms. Deletions from the centromere to 13q32 or any deletions including the 13q32 band are associated with slow growth, intellectual disability, and congenital malformations. Deletions from 13q33 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.
13q deletion syndrome 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 associated with 13q deletion syndrome. 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.