Cryptorchidism, or failure of testicular descent, is a common human congenital abnormality with a multifactorial etiology that likely reflects the involvement of endocrine, environmental, and hereditary factors. Cryptorchidism can result in infertility and increases risk for testicular tumors. Testicular descent from abdomen to scrotum occurs in 2 distinct phases: the transabdominal phase and the inguinoscrotal phase (summary by Gorlov et al., 2002).

Difficulty in swallowing.

An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age.

A foot where the longitudinal arch of the foot is in contact with the ground or floor when the individual is standing; or, in a patient lying supine, a foot where the arch is in contact with the surface of a flat board pressed against the sole of the foot by the examiner with a pressure similar to that expected from weight bearing; or, the height of the arch is reduced.

An abnormality of vibrational conductance of sound to the inner ear leading to impairment of sensory perception of sound.

Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (see 300000), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).

Developmental hypoplasia of the mandible.

Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.

Passing the age when puberty normally occurs with no physical or hormonal signs of the onset of puberty.

Underdevelopment of the external ear.

Bilateral bulging of the lateral frontal bone prominences with relative sparing of the midline.

Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.

Increased volume and globular shape of the anteroinferior aspect of the nose.

Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape.

Constipation for longer than three months with fewer than 3 bowel movements per week, straining, lumpy or hard stools, and a sensation of anorectal obstruction or incomplete defecation.

The palpebral fissure inclination is more than two standard deviations below the mean.

An eye that is more deeply recessed into the plane of the face than is typical.

Premature development of the breasts.

Absence of one half of the vertebral body in the lumbar spine.

Epicanthus is a condition in which a fold of skin stretches from the upper to the lower eyelid, partially covering the inner canthus. Usher (1935) noted that epicanthus is a normal finding in the fetus of all races. Epicanthus also occurs in association with hereditary ptosis (110100).

Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior.

Accumulation of fluid in the peritoneal cavity during the fetal period.

One or more bent (flexed) toe joints that cannot be straightened actively or passively.

Thinned, deficient, or excessively arched ala nasi.

Underdevelopment of the toenail.

The ability of a joint to move beyond its normal range of motion.

Laterally protruding ear that lacks antihelical folding (including absence of inferior and superior crura).

Median longitudinal ear length greater than two SD above the mean determined by the maximal distance from the superior aspect to the inferior aspect of the external ear.

Distance between medial and lateral canthi is more than two standard deviations above the mean for age (objective); or, apparently increased length of the palpebral fissures.

Regional increase in the width (height) of the eyebrow.

Decreased number of hairs per unit area of skin of the scalp.

Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective).

Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period.

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention.

Head circumference below 2 standard deviations below the mean for age and gender at birth.

Cleft palate is a developmental defect of the palate resulting from a failure of fusion of the palatine processes and manifesting as a separation of the roof of the mouth (soft and hard palate).

Underdevelopment of the lower eyelid.

A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter.