Absence of both testes from the scrotum owing to failure of the testis or testes to descend through the inguinal canal to the scrotum.

Bilateral clubfoot deformity.

Short distance from the end of the finger to the most distal interphalangeal crease or the distal interphalangeal joint flexion point. That is, hypoplasia of one or more of the distal phalanx of finger.

The middle finger is more than 2 SD above the mean for newborns 27 to 41 weeks EGA or above the 97th centile for children from birth to 16 years of age AND the five digits retain their normal length proportions relative to each other (i.e., it is not the case that the middle finger is the only lengthened digit), or, Fingers that appear disproportionately long compared to the palm of the hand.

Syndactyly with fusion of the fingers two to four.

Syndactyly with fusion of toes two to five.

A soft tissue continuity in the anteroposterior axis between the second to the fifth fingers that extends distally to at least the level of the proximal interphalangeal joints.

In utero, the ductus arteriosus (DA) serves to divert ventricular output away from the lungs and toward the placenta by connecting the main pulmonary artery to the descending aorta. A patent ductus arteriosus (PDA) in the first 3 days of life is a physiologic shunt in healthy term and preterm newborn infants, and normally is substantially closed within about 24 hours after bith and completely closed after about three weeks. Failure of physiologcal closure is referred to a persistent or patent ductus arteriosus (PDA). Depending on the degree of left-to-right shunting, PDA can have clinical consequences.

Failure of the foramen ovale to seal postnatally, leaving a potential conduit between the left and right cardiac atria.

Congenital absence of the anus, i.e., the opening at the bottom end of the intestinal tract.

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

Underdevelopment of the external ear.

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.

A decreased magnitude of the sensory perception of sound.

A condition in which the helix is folded over to a greater degree than normal. That is, excessive curling of the helix edge, whereby the free edge is parallel to the plane of the ear.

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

An abnormal orientation of the earlobes such that they point out- and upward. That is, the lateral surface of ear lobe faces superiorly.

Distortion of the course of the normal folds of the ear and the appearance of supernumerary crura and folds.

Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time.

A degree of language development that is significantly below the norm for a child of a specified age.

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

Developmental hypoplasia of the mandible.

An abnormality of skull shape characterized by a decreased anterior-posterior diameter. That is, a cephalic index greater than 81%. Alternatively, an apparently shortened anteroposterior dimension (length) of the head compared to width.

Reduced width of the chest from side to side, associated with a reduced distance from the sternal notch to the tip of the shoulder.

Reduced length of the clavicles.

Reduced convexity of the occiput (posterior part of skull).

Vertical bony ridge positioned in the midline of the forehead.

Enlargement of the anterior fontanelle with respect to age-dependent norms.

Absence (aplasia) of the spleen.

Absence or abnormal closure of the choana (the posterior nasal aperture). Most embryologists believe that posterior choanal atresia results from a failure of rupture between the 35th and 38th day of fetal life of the partition which separates the bucconasal or buccopharyngeal membranes. The resultant choanal atresia may be unilateral or bilateral, bony or membranous, complete or incomplete. In over 90 per cent of cases the obstruction is bony, while in the remainder it is membranous. The bony type of atresia is commonly located 1-2 mm. anterior to the posterior edge of the hard palate, and the osseous septum varies in thickness from 1 to 10 mm. In the membranous form of choanal atresia the obstruction usually occurs further posteriorly. In approximately one third of cases the atresia is bilateral.

Distance between the commissures of the mouth more than 2 SD below the mean. Alternatively, an apparently decreased width of the oral aperture (subjective).

Inability of velopharyngeal sphincter to sufficiently separate the nasal cavity from the oral cavity during speech.

Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).

Increase in width of the nasal tip.

Thinned, deficient, or excessively arched ala nasi.

Distance between the hairline (trichion) and the glabella (the most prominent point on the frontal bone above the root of the nose), in the midline, more than two SD below the mean. Alternatively, an apparently decreased distance between the hairline and the glabella.

Increased breadth of the nasal bridge (and with it, the nasal root).

Cleft palate of the midline of the palate.

Posterior positions and/or vertical shortening of the infraorbital and perialar regions, or increased concavity of the face and/or reduced nasolabial angle.

Frontal hairline with bilateral arcs to a low point in the midline of the forehead.

Increased side-to-side width of the neck.

Columella extending inferior to the level of the nasal base, when viewed from the side.

Reduced distance from the anterior border of the naris to the subnasale.

Distance between nasal base and midline upper lip vermilion border more than 2 SD below the mean. Alternatively, an apparently decreased distance between nasal base and midline upper lip vermilion border.

A short discontinuity of the margin of the upper eyelid.

A nail that is diminished in length and width, i.e., underdeveloped nail.

Abnormally increased hair growth over much of the entire body.

The presence of excess amniotic fluid in the uterus during pregnancy.

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).