Trisomy 13 syndrome

Trisomy 13 syndrome, also known as Patau syndrome, is a severe chromosomal disorder caused by the presence of an extra copy of chromosome 13 in some or all of the body's cells. It is the third most common autosomal trisomy in live-born infants, after trisomy 21 (Down syndrome) and trisomy 18 (Edwards syndrome). The condition can result from full trisomy 13, translocation trisomy 13, or mosaic trisomy 13, which accounts for the range of ICD-10 codes associated with this diagnosis. Trisomy 13 affects virtually every organ system and is characterized by a distinctive pattern of severe congenital anomalies. Key features include holoprosencephaly (a failure of the forebrain to divide properly), severe intellectual disability, midline facial defects such as cleft lip and cleft palate (often bilateral), microphthalmia or anophthalmia (small or absent eyes), postaxial polydactyly (extra fingers or toes), congenital heart defects (particularly ventricular septal defects, atrial septal defects, and patent ductus arteriosus), scalp defects (cutis aplasia), and renal anomalies. Microcephaly, low-set malformed ears, and omphalocele may also be present. Affected infants typically have profound developmental delay and failure to thrive. The prognosis for trisomy 13 is very poor. The median survival is approximately 7 to 10 days, and more than 80% of affected infants do not survive beyond the first month of life. Approximately 5–10% survive beyond the first year, particularly those with mosaic trisomy 13, who may have a milder phenotype. There is no cure for trisomy 13. Treatment is supportive and palliative, focusing on comfort care and management of specific complications. Some families may elect surgical intervention for certain correctable anomalies such as heart defects, though this remains a subject of ethical discussion. Prenatal diagnosis is possible through amniocentesis, chorionic villus sampling, or non-invasive prenatal testing, and the condition may be suspected on prenatal ultrasound.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Trisomy 13 syndrome