Synonyms:

Chromosome 4, Partial Trisomy 4p
Chromosome 4, Trisomy 4p
Chromosome 4p Syndrome

Chromosome 4, Trisomy 4p is a rare chromosome disorder in which all or a portion of the short arm (p)of chromosome 4 appears three times (trisomy) rather than twice in cells of the body. Associated symptoms and physical findings may vary greatly in range and severity from case to case. Such variability may depend upon the specific length and location of the deplicated (trisomic) portion of chromosome 4 p as well as other factors. Many affected infants may have feeding and breathing difficulties, characteristic malformations of the head and facial (craniofacial) area, and abnormalities of the hands and feet. Other features can include skeletal defects, genital abnormalities in affected males, or heart (cardiac) defects. Trisomy 4p is also characterized by severe mental retardation