Trisomy 13

Disease Overview

Trisomy 13 is a type of chromosome disorder characterized by having 3 copies of chromosome 13 in cells of the body, instead of the usual 2 copies. In some people, only a portion of cells contains the extra chromosome 13 (called mosaic trisomy 13), whereas other cells contain the normal chromosome pair.[1704][1705][1706] Trisomy 13 causes severe intellectual disability and many physical abnormalities, such as congenital heart defects; brain or spinal cord abnormalities; very small or poorly developed eyes (microphthalmia); extra fingers or toes; cleft lip with or without cleft palate; and weak muscle tone (hypotonia). Most cases are not inherited and result from a random error during the formation of eggs or sperm in healthy parents.[1705] Trisomy 13 is diagnosed based on the symptoms, clinical exam, and confirmed by the results of a chromosome test. Due to various life-threatening medical problems, many infants with trisomy 13 do not survive past the first days or weeks of life.[1705]

Synonyms

• Patau syndrome
• Chromosome 13, trisomy 13 complete
• Complete trisomy 13 syndrome
• D trisomy syndrome (formerly)