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).

Clubfoot is a congenital limb deformity defined as fixation of the foot in cavus, adductus, varus, and equinus (i.e., inclined inwards, axially rotated outwards, and pointing downwards) with concomitant soft tissue abnormalities (Cardy et al., 2007). Clubfoot may occur in isolation or as part of a syndrome (e.g., diastrophic dysplasia, 222600). Clubfoot has been reported with deficiency of long bones and mirror-image polydactyly (Gurnett et al., 2008; Klopocki et al., 2012).

Slippage of the FEMUR off the TIBIA.

Spoon-shaped, broad thumbs.

The presence of more than the normal number of carpal bones.

A deformity of foot and ankle in which the foot is bent down and outwards.

A delay in the process of formation and maturation of the epiphysis of one or more long bones.

A two-part calcaneus, a finding that probably results from delayed coalescence of two primary calcaneal centers of ossification.

Diminished length of one or more metacarpal bones in relation to the others of the same hand or to the contralateral metacarpal.

Diminished length of a metatarsal bone, with resultant proximal displacement of the associated toe.

Aortic dilatation refers to a dimension that is greater than the 95th percentile for the normal person age, sex and body size. In contrast, an aneurysm is defined as a localized dilation of the aorta that is more than 150 percent of predicted (ratio of observed to expected diameter 1.5 or more). Aneurysm should be distinguished from ectasia, which represents a diffuse dilation of the aorta less than 50 percent of normal aorta diameter.

Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum.

A hole between the two bottom chambers (ventricles) of the heart. The defect is centered around the most superior aspect of the ventricular septum.

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

A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).

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

A decreased magnitude of the sensory perception of sound.

External mechanical compression of the spinal cord.

The closed form of spina bifida with incomplete closure of a vertebral body with intact overlying skin.

Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.

Displacement of the femur from its normal location in the hip joint.

The presence of an abnormal lateral curvature of the spine.

Spondylolysis is an osseous defect of the pars interarticularis, thought to be a developmental or acquired stress fracture secondary to chronic low-grade trauma.

A deformity of the chest caused by overgrowth of the ribs and characterized by protrusion of the sternum.

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

Exaggerated convexity of the cervical vertebral column, causing the cervical spine to bow outwards and take on a rounded appearance.

The capability that a joint (or a group of joints) has to move, passively and/or actively, beyond normal limits along physiological axes.

Anterior tongue-like protrusions of the vertebral bodies.

Underdevelopment of the malar prominence of the jugal bone (zygomatic bone in mammals), appreciated in profile, frontal view, and/or by palpation.

Reduced depth of the orbits associated with prominent-appearing ocular globes.

A defect of the chest wall characterized by a depression of the sternum, giving the chest ("pectus") a caved-in ("excavatum") appearance.

Dislocation of the distal humerus out of the elbow joint, where the radius, ulna, and humerus meet.

An injury of the wrist with displacement of any of the eight carpal bones.

A developmental defect leading to the union of two adjacent vertebrae.

Narrowing of the lumen of the trachea.

Weakness or softness of the cartilage in the walls of the bronchial tubes.

Congenital tracheomalacia is a rare condition where the trachea is soft and flexible causing the tracheal wall to collapse when exhaling, coughing or crying, that usually presents in infancy, and that is characterized by stridor and noisy breathing or upper respiratory infections. Tracheomalacia improves by the age of 18-24 months.

A gap or groove in the upper lip. This is a congenital defect resulting from nonfusion of tissues of the lip during embryonal development.

Tooth agenesis in some form is a common human anomaly that affects approximately 20% of the population. Although tooth agenesis is associated with numerous syndromes, several case reports describe nonsyndromic forms that are either sporadic or familial in nature, as reviewed by Gorlin et al. (1990). The incidence of familial tooth agenesis varies with each class of teeth. Most commonly affected are third molars (wisdom teeth), followed by either upper lateral incisors or lower second premolars; agenesis involving first and second molars is very rare. Also see 114600 and 302400. Selective tooth agenesis without associated systemic disorders has sometimes been divided into 2 types: oligodontia, defined as agenesis of 6 or more permanent teeth, and hypodontia, defined as agenesis of less than 6 teeth. The number in both cases does not include absence of third molars (wisdom teeth). Faulty use of the terms, however, have confounded their use. The term 'partial anodontia' is obsolete (Salinas, 1978). Genetic Heterogeneity of Selective Tooth Agenesis Other forms of selective tooth agenesis include STHAG2 (602639), mapped to chromosome 16q12; STHAG3 (604625), caused by mutation in the PAX9 gene (167416) on chromosome 14q12; STHAG4 (150400), caused by mutation in the WNT10A gene (606268) on chromosome 2q35; STHAG5 (610926), mapped to chromosome 10q11; STHAG7 (616724), caused by mutation in the LRP6 gene (603507) on chromosome 12p13; STHAG8 (617073), caused by mutation in the WNT10B gene (601906) on chromosome 12q13; STHAG9 (617275), caused by mutation in the GREM2 gene (608832) on chromosome 1q43; STHAG10 (620173), caused by mutation in the TSPEAR gene (612920) on chromosome 21q22; and STHAGX1 (313500), caused by mutation in the EDA gene (300451) on chromosome Xq13. A type of selective tooth agenesis that was formerly designated STHAG6 has been incorporated into the dental anomalies and short stature syndrome (DASS; 601216). Of 34 unrelated patients with nonsyndromic tooth agenesis, van den Boogaard et al. (2012) found that 56% (19 patients) had mutations in the WNT10A gene (STHAG4), whereas only 3% and 9% had mutations in the MSX1 (STHAG1) and PAX9 (STHAG3) genes, respectively. The authors concluded that WNT10A is a major gene in the etiology of isolated hypodontia. Genotype-Phenotype Correlations Yu et al. (2016) observed that the most frequently missing permanent teeth in WNT10B-associated oligodontia were the lateral incisors (83.3%), whereas premolars were missing only 51.4% of the time, which they noted was a pattern 'clearly different' from the oligodontia patterns resulting from WNT10A mutations. They also stated that the selective pattern in WNT10B mutants was different from that associated with mutations in other genes, such as MSX1, in which second premolars are missing, and PAX9, in which there is agenesis of molars.

Posterior positioning of the nasal root in relation to the overall facial profile for age.

Forward prominence of the entire forehead, due to protrusion of the frontal bone.

Absence of concavity or convexity of the face when viewed in profile.

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

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).

Decreased length of nail.

A reduction of corneal clarity.

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).