Webbing or fusion of the fingers or toes, involving soft parts only or including bone structure. Bony fusions are referred to as "bony" syndactyly if the fusion occurs in a radio-ulnar axis. Fusions of bones of the fingers or toes in a proximo-distal axis are referred to as "symphalangism".

A thumb with three phalanges in a single, proximo-distal axis. Thus, this term applies if the thumb has an accessory phalanx, leading to a digit like appearance of the thumb.

Familial isolated clinodactyly of fingers is a rare, genetic, non-syndromic, congenital limb malformation disorder characterized by angulation of a digit in the radio-ulnar (coronal) plane, away from the axis of joint flexion-extension, in several members of a single family with no other associated manifestations. Deviation is usually bilateral and commonly involves the fifth finger. Affected digits present trapezoidal or delta-shaped phalanges on imaging.

The distal and proximal transverse palmar creases are merged into a single transverse palmar crease.

Hypoplasia (congenital reduction in size) of the thumb.

Supernumerary digits located at the ulnar side of the hand (that is, on the side with the fifth finger).

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

An abnormal position of the hand in which the wrist is bent toward the radius (i.e., toward the thumb).

Bending or curvature of a thumb towards the ulnar side (towards the ring finger).

Underdevelopment of the radius.

Missing radius bone associated with congenital failure of development.

Underdevelopment of the humerus.

Hypoplastic/small middle phalanx of the fifth finger.

Arm shortening because of underdevelopment of one or more bones of the upper extremity.

Absent first metacarpal (long bone) of the hand.

An abnormality affecting the carpal bones of the wrist (scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, hamate).

Underdevelopment of the thenar eminence with reduced palmar soft tissue mass surrounding the base of the thumb.

A developmental defect characterized by reduced length of the first metacarpal (long bone) of the hand.

Clinodactyly refers to a bending or curvature of the fifth finger in the radial direction (i.e., towards the 4th finger).

A bending or abnormal curvature of the radius.

Underdevelopment of the ulna.

A limitation of the ability to place the forearm in a position such that the palm faces anteriorly (supination) and to place the forearm in a position such that the palm faces posteriorly (pronation).

Reduced muscle mass on the ulnar side of the palm, that is, reduction in size of the hypothenar eminence.

Proximal mislocalization of the thumb.

Bending of the diaphysis (shaft) of the ulna.

Limited ability to straighten the arm at the elbow joint.

Missing ulna bone associated with congenital failure of development.

Absent thumb, i.e., the absence of both phalanges of a thumb and the associated soft tissues.

Partial or complete duplication of distal phalanx of third toe.

Hypoplasia (congenital reduction in size) of the middle phalanx of the second finger, also known as the index finger.

Absent 2nd (index) finger.

A soft tissue continuity in the A/P axis between fingers 3 and 4.

One or more digit that appears disproportionately short compared to the hand/foot, whereby either the entire digit or a specific phalanx is shortened.

A soft tissue continuity in the anteroposterior axis between the thumb to the index finger that extends distally to at least the level of the proximal interphalangeal joints.

Y-shaped metatarsals are the result of a partial fusion of two metatarsal bones, with the two arms of the Y pointing in the distal direction. Y-shaped metatarsals may be seen in combination with polydactyly.

Amelia of one or both upper limbs.

Insertion of thumb at a more distal location than normal.

Absent 3rd finger.

A partial duplication, depending on severity leading to a broad or bifid appearance, affecting one or more of the phalanges of the thumb. As opposed to a complete duplication there is still a variable degree of fusion between the duplicated bones.

Underdevelopment of both forearm bones, the ulna and the radius, resulting in a shortened forearm.

Atrioventricular (AV) dissociation is present if the atria and the ventricles are under the control of two separate pacemakers. AV dissociation can occur in the absence of a primary AV conduction disturbance.

Double outlet right ventricle (DORV) is a type of ventriculoarterial connection in which both great vessels arise entirely or predominantly from the right ventricle.

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.

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 abnormality of the mitral valve characterized by insufficiency or incompetence of the mitral valve resulting in retrograde leaking of blood through the mitral valve upon ventricular contraction.

One or both of the leaflets (cusps) of the mitral valve bulges back into the left atrium upon contraction of the left ventricle.

Failure of the tricuspid valve to close sufficiently upon contraction of the right ventricle, causing blood to regurgitate (flow backward) into the right atrium.

One or more of the leaflets (cusps) of the tricuspid valve bulges back into the right atrium upon contraction of the right ventricle.

A tachycardia originating in the ventricles characterized by rapid heart rate (over 100 beats per minute) and broad QRS complexes (over 120 ms).

Bradycardia related to a mean resting sinus rate of less than 50 beats per minute.

Delay of conduction through the atrioventricular node, which is manifested as prolongation of the PR interval in the electrocardiogram (EKG). All atrial impulses reach the ventricles.

Third-degree atrioventricular (AV) block (also referred to as complete heart block) is the complete dissociation of the atria and the ventricles. Third-degree AV block exists when more P waves than QRS complexes exist and no relationship (no conduction) exists between them.

Critical congenital heart disease (CCHD) is a term that refers to a group of serious heart defects that are present from birth. These abnormalities result from problems with the formation of one or more parts of the heart during the early stages of embryonic development. CCHD prevents the heart from pumping blood effectively or reduces the amount of oxygen in the blood. As a result, organs and tissues throughout the body do not receive enough oxygen, which can lead to organ damage and life-threatening complications. Individuals with CCHD usually require surgery soon after birth.\n\nAlthough babies with CCHD may appear healthy for the first few hours or days of life, signs and symptoms soon become apparent. These can include an abnormal heart sound during a heartbeat (heart murmur), rapid breathing (tachypnea), low blood pressure (hypotension), low levels of oxygen in the blood (hypoxemia), and a blue or purple tint to the skin caused by a shortage of oxygen (cyanosis). If untreated, CCHD can lead to shock, coma, and death. However, most people with CCHD now survive past infancy due to improvements in early detection, diagnosis, and treatment.\n\nPeople with CCHD have one or more specific heart defects. The heart defects classified as CCHD include coarctation of the aorta, double-outlet right ventricle, D-transposition of the great arteries, Ebstein anomaly, hypoplastic left heart syndrome, interrupted aortic arch, pulmonary atresia with intact septum, single ventricle, total anomalous pulmonary venous connection, tetralogy of Fallot, tricuspid atresia, and truncus arteriosus.\n\nSome people with treated CCHD have few related health problems later in life. However, long-term effects of CCHD can include delayed development and reduced stamina during exercise. Adults with these heart defects have an increased risk of abnormal heart rhythms, heart failure, sudden cardiac arrest, stroke, and premature death.\n\nEach of the heart defects associated with CCHD affects the flow of blood into, out of, or through the heart. Some of the heart defects involve structures within the heart itself, such as the two lower chambers of the heart (the ventricles) or the valves that control blood flow through the heart. Others affect the structure of the large blood vessels leading into and out of the heart (including the aorta and pulmonary artery). Still others involve a combination of these structural abnormalities.

A congenital heart defect characterized by a specific combination of heart defects with a common atrioventricular valve, primum atrial septal defect and inlet ventricular septal defect.

A rare congenital vascular anomaly that results when the left superior cardinal vein caudal to the innominate vein fails to regress.

A kind of atrial septum defect arising from an enlarged foramen ovale, inadequate growth of the septum secundum, or excessive absorption of the septum primum.

An interatrial communication caused by a deficiency of the common wall between the superior vena cava (SVC) and the right-sided pulmonary veins. SVASD is commonly associated with anomalous pulmonary venous connection (APVC) of some or all of the pulmonary veins, which produces additional left-to-right shunting.

A ventricular septal defect that is confluent with and involves the membranous septum and is bordered by an atrioventricular valve, not including the type 3 VSDs.

Complete absence of the interatrial septum with common atrioventricular valve and two atrioventricular connections.

The trabecular septum is the largest part of the interventricular septum. It extends from the membranous septum to the apex and superiorly to the infundibular septum. A defect in the trabecular septum is called muscular VSD if the defect is completely rimmed by muscle.

Increase in size of the right atrium.

Any anomaly of the progression of electrical impulses through the heart.

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).

Pulmonary hypertension is defined mean pulmonary artery pressure of 25mmHg or more and pulmonary capillary wedge pressure of 15mmHg or less when measured by right heart catheterisation at rest and in a supine position.

Left ventricular non-compaction (LVNC) is characterized by prominent left ventricular trabeculae and deep inter-trabecular recesses. The myocardial wall is often thickened with a thin, compacted epicardial layer and a thickened endocardial layer. In some patients, LVNC is associated with left ventricular dilatation and systolic dysfunction, which can be transient in neonates.

Isolated abnormalities of the coronary artery origins. This may be in associated with other structural heart malformations but not the patterns of complex structural heart malformations which result in abnormal course of the coronary arteries.

Underdevelopment or reduced size of the heart right ventricle, often due to a reduced number of cells.

A bulging of the interatrial septum towards one side. In adults, atrial septal aneurysm can be defined as a protrusion of the aneurysm of >10 mm beyond the plane of the atrial septum as measured by transesophageal echocardiography.

A developmental anomaly of the heart characterized by the presence of three atria because the left atrium is divided by an abnormal septum.

Unroofed coronary sinus (CS) is a rare congenital cardiac anomaly in which there is partial (either focal or fenestrated) or complete absence of the roof of the CS, which results in a communication between the CS and the LA. Unroofed CS is the rarest type of atrial septal defect. It is often associated with persistent left superior vena cava (LSVC) and other forms of complex congenital heart disease, usually heterotaxia syndromes. The morphological types have been classified into 4 groups

A left-right reversal (or mirror reflection) of the anatomical location of the viscera of the abdomen.

Klippel-Feil syndrome (KFS) is a congenital anomaly characterized by a defect in the formation or segmentation of the cervical vertebrae, resulting in a fused appearance. The clinical triad consists of short neck, low posterior hairline, and limited neck movement, although less than 50% of patients demonstrate all 3 clinical features (Tracy et al., 2004). Genetic Heterogeneity of Klippel-Feil Syndrome Additional forms of KFS include autosomal recessive KFS2 (214300), caused by mutation in the MEOX1 gene (600147) on chromosome 17q21, autosomal dominant KFS3 (613702), caused by mutation in the GDF3 gene (606522) on chromosome 12p13, and autosomal recessive KFS4 (616549), caused by mutation in the MYO18B gene (607295) on chromosome 22q12. See also MURCS association (601076), in which Klippel-Feil anomaly is associated with urogenital anomalies.

Developmental hypoplasia of the mandible.

Missing or malformed long bones of the extremities with the distal parts (such as hands and/or feet) connected to the variably shortened or even absent extremity, leading to a flipper-like appearance, as opposed to other forms of limb malformations were either the hole limb is missing (such as amelia), or the distal part of a limb is absent (peromelia).

A displacement or misalignment of the humerus with respect to the other bones of the should joint. Note that a subluxation is a partial dislocation.

An abnormal osseous union (fusion) between the radius and the ulna.

An abnormality of skull shape characterized by a increased anterior-posterior diameter, i.e., an increased antero-posterior dimension of the skull. Cephalic index less than 76%. Alternatively, an apparently increased antero-posterior length of the head compared to width. Often due to premature closure of the sagittal suture.

Missing or malformed long bones of the upper limbs with the distal parts (the hands) connected to the variably shortened or even absent upper extremity, leading to a flipper-like appearance, as opposed to other forms of limb malformations were either the whole limb is missing (such as amelia), or the distal part of a limb is absent (peromelia).

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.

A broad chest.

Presence of only 11 pairs of ribs.

Underdeveloped scapula.

Low set, steeply sloping shoulders.

Underdevelopment of the deltoid muscle.

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.

Absence of the pectoralis major muscle.

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).

Cleft of the soft palate (also known as the velum, or muscular palate) as a result of a developmental defect occurring between the 7th and 12th week of pregnancy. Cleft soft palate can cause functional abnormalities of the Eustachian tube with resulting middle ear anomalies and hearing difficulties, as well as speech problems associated with hypernasal speech due to velopharyngeal insufficiency.

Diminished length of the neck.

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

A cutaneous indentation resulting from tethering of the skin to underlying structures (bone) of the intergluteal cleft.