Penta X Syndrome is a rare chromosomal disorder that affects females. Females normally have two X chromosomes. However, in those with Penta X Syndrome, there are three additional (or a total of five) X chromosomes in the nuclei of body cells (pentasomy X). The condition is typically characterized by moderate to severe mental retardation, short stature, malformations of the skull and facial (craniofacial) region, and/or other physical abnormalities. Characteristic craniofacial malformations may include upslanting eyelid folds (palpebral fissures), a flat nasal bridge, malformed ears, a short neck with a low hairline, and/or other findings. Penta X Syndrome may also be characterized by abnormal deviation (clinodactyly) or permanent flexion (camptodactyly) of the "pinkies" or fifth fingers; heart and/or kidney defects; deficient development of the ovaries and uterus; and/or other physical findings. The disorder results from errors during the division of reproductive cells in one of the parents.
(Please note that some of these organizations may provide information concerning certain conditions potentially associated with this disorder [e.g., craniofacial abnormalities, congenital heart defects, mental retardation].)
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