Chromosome 14 trisomy syndrome. Trisomy 14.
Incidence
Trisomy 14 has been reported mainly in abortuses, but rarely in liveborn infants; most living examples represent trisomy 14 mosaicism.
Clinical Characteristics
Chromosome 14, Trisomy Mosaic is a rare chromosomal disorder in which chromosome 14 appears three times (trisomy) rather than twice in some cells of the body. The term "mosaic" indicates that some cells contain the extra chromosome 14, whereas others have the normal chromosomal pair.The disorder may be characterized by growth delays before birth (intrauterine growth retardation); failure to grow and gain weight at the expected rate (failure to thrive) during infancy; delays in the acquisition of skills requiring the coordination of mental and physical abilities (psychomotor delays); and mental retardation. Affected infants also have distinctive abnormalities of the head and facial (craniofacial) region, such as a prominent forehead; deeply set, widely spaced eyes; a broad nasal bridge; and low-set, malformed ears. Additional craniofacial abnormalities may include an unusually small lower jaw (micrognathia); a large mouth and thick lips; and incomplete closure or abnormally high arching of the roof of the mouth (palate). Many affected infants also have structural malformations of the heart (e.g., tetralogy of Fallot). In some cases, additional physical abnormalities may also be present. In summary, it is related to the presence of an additional (third) chromosome in an otherwise diploid chromosome 14, associated with variable clinical manifestations consisting of growth and psychomotor delay, failure to thrive, minor facial abnormalities, cleft palate, congenital heart defect, body asymmetry, genital anomalies, and skin pigmentation.
Precipitants
None
Provocation Tests
None
Diagnostic Procedures
Karyotype. Chromosome 14 trisomy, but most living examples represent trisomy 14 mosaicism.