Describes a foot digit resting on the dorsal surface of an adjacent digit when the foot is at rest. Initially clawing may be dynamic and only noticeable on walking. Over time the plantar plate tears, subluxation occurs at the metatarsophalangeal joint (MTPJ), and the deformity becomes permanent.

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.

A narrowing of the right ventricular outflow tract that can occur at the pulmonary valve (valvular stenosis), below the pulmonary valve (infundibular stenosis), or above the pulmonary valve (supravalvar stenosis).

Pyloric stenosis, also known as infantile hypertrophic pyloric stenosis, is an uncommon condition in infants characterized by abnormal thickening of the pylorus muscles in the stomach leading to gastric outlet obstruction. Clinically infants are well at birth. Then, at 3 to 6 weeks of age, the infants present with projectile vomiting, potentially leading to dehydration and weight loss.

The distal interphalangeal joint and/or the proximal interphalangeal joint of the fingers or toes cannot be extended to 180 degrees by either active or passive extension.

Legg-Calve-Perthes disease (LCPD) is characterized by loss of circulation to the femoral head, resulting in avascular necrosis in a growing child. Clinical pictures of the disease vary, depending on the phase of disease progression through ischemia, revascularization, fracture and collapse, and repair and remodeling of the bone. The disease occurs more frequently in boys, and most patients tend to be shorter than their peers. Both familial and isolated cases of LCPD have been reported (summary by Chen et al., 2004).

Multiple congenital contractures in different body areas.

Asthma is characterized by increased responsiveness of the tracheobronchial tree to multiple stimuli, leading to narrowing of the air passages with resultant dyspnea, cough, and wheezing.

Atopic dermatitis (ATOD), also known as eczema, is a common chronic pruritic inflammatory skin disease with a strong genetic component. Onset typically occurs during the first 2 years of life (review by Soderhall et al., 2007). Genetic Heterogeneity of Atopic Dermatitis Many inflammatory diseases, such as atopic eczema, are genetically complex, with multiple alleles at several loci thought to be involved in their pathogenesis. Several susceptibility loci for atopic dermatitis have been identified: ATOD1 on chromosome 3q21, ATOD2 (605803) on chromosome 1q21, ATOD3 (605804) on chromosome 20p, ATOD4 (605805) on chromosome 17q25.3, ATOD5 (603165) on chromosome 13q12-q14, ATOD6 (605845) on chromosome 5q31-q33, ATOD7 (613064) on chromosome 11q13.5, ATOD8 (613518) on chromosome 4q22.1, and ATOD9 (613519) on chromosome 3p24.

Increased prominence or roundness of soft tissues between zygomata and mandible.

A limitation of the ability to direct one's gaze above the horizontal meridian.