Notes

short stature. moderate to severe mental retardation.
unusually small head, a round face, upslanting eyelid folds, a flat nasal bridge, malformed ears, A short neck with a low hairline, widely spaced eyes; vertical skin folds that may cover the eyes’ inner corners (epicanthal folds); drooping of the upper eyelids (ptosis);a small jaw (micrognathia); thick lips; incomplete closure of the roof of the mouth (cleft palate); abnormal contact of the teeth of the upper jaw with those of the lower jaw (malocclusion); unusually shaped molars with large pulp spaces (taurodontism); and/or enamel defects, potentially resulting in premature loss of certain “baby” (deciduous or primary) teeth.

abnormal fusion of the forearm bones (radioulnar synostosis); narrow shoulders; and/or unusually small hands with abnormal deviation (clinodactyly) or permanent flexion (camptodactyly) of the fifth fingers. Additional findings may include overlapping toes; a foot deformity in which the sole is turned inward (metatarsus varus); and/or an abnormality in which the knees are unusually close together and the space between the ankles is increased (“knock knees” [genua valga]). Some affected females also have overflexion or bending (i.e., hyperflexion) or dislocations of multiple joints, including those of the fingers, wrists, shoulders, elbows, and/or hips. In addition, reports indicate that some affected individuals may have abnormal skin ridge patterns (dermatoglyphics) on the fingers and palms of the hands.

In some cases, Penta X Syndrome may be associated with certain structural malformations of the heart at birth (congenital heart defects). Such defects may include an abnormal opening in the fibrous partition (septum) that normally separates the two lower chambers of the heart (ventricular septal defect [VSD]); patent ductus arteriosus (PDA); and/or other malformations. In PDA, the channel that is present between the aorta and the pulmonary artery during fetal development fails to close after birth, leaving an abnormal opening between the arteries. (The pulmonary artery transports oxygen-depleted [deoxygenated] blood from the right ventricle to the lungs, where the exchange of oxygen and carbon dioxide takes place. The aorta is the main artery of the body that arises from the left ventricle and supplies oxygenated blood to body tissues.)

Some females with Penta X Syndrome also have certain kidney (renal) abnormalities, such as underdevelopment of the kidneys (renal hypoplasia), horseshoe kidney, and/or other findings. Horseshoe kidney is a congenital abnormality in which the two kidneys are joined at the base.

In some cases, affected females may also have an unusually small uterus, deficient development of the ovaries, and/or other abnormalities. In addition, delayed puberty has been reported in some instances.