An angulation of a digit at an interphalangeal joint in the plane of the palm (finger) or sole (toe).

Familial dilated cardiomyopathy is a genetic form of heart disease. It occurs when heart (cardiac) muscle becomes thin and weakened in at least one chamber of the heart, causing the open area of the chamber to become enlarged (dilated). As a result, the heart is unable to pump blood as efficiently as usual. To compensate, the heart attempts to increase the amount of blood being pumped through the heart, leading to further thinning and weakening of the cardiac muscle. Over time, this condition results in heart failure.\n\nIt usually takes many years for symptoms of familial dilated cardiomyopathy to cause health problems. They typically begin in mid-adulthood, but can occur at any time from infancy to late adulthood. Signs and symptoms of familial dilated cardiomyopathy can include an irregular heartbeat (arrhythmia), shortness of breath (dyspnea), extreme tiredness (fatigue), fainting episodes (syncope), and swelling of the legs and feet. In some cases, the first sign of the disorder is sudden cardiac death. The severity of the condition varies among affected individuals, even in members of the same family.

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.

Wolff-Parkinson-White syndrome is a condition characterized by abnormal electrical pathways in the heart that cause a disruption of the heart's normal rhythm (arrhythmia).\n\nThe heartbeat is controlled by electrical signals that move through the heart in a highly coordinated way. A specialized cluster of cells called the atrioventricular node conducts electrical impulses from the heart's upper chambers (the atria) to the lower chambers (the ventricles). Impulses move through the atrioventricular node during each heartbeat, stimulating the ventricles to contract slightly later than the atria.\n\nPeople with Wolff-Parkinson-White syndrome are born with an extra connection in the heart, called an accessory pathway, that allows electrical signals to bypass the atrioventricular node and move from the atria to the ventricles faster than usual. The accessory pathway may also transmit electrical impulses abnormally from the ventricles back to the atria. This extra connection can disrupt the coordinated movement of electrical signals through the heart, leading to an abnormally fast heartbeat (tachycardia) and other changes in heart rhythm. Resulting symptoms include dizziness, a sensation of fluttering or pounding in the chest (palpitations), shortness of breath, and fainting (syncope). In rare cases, arrhythmias associated with Wolff-Parkinson-White syndrome can lead to cardiac arrest and sudden death. The most common arrhythmia associated with Wolff-Parkinson-White syndrome is called paroxysmal supraventricular tachycardia.\n\nComplications of Wolff-Parkinson-White syndrome can occur at any age, although some individuals born with an accessory pathway in the heart never experience any health problems associated with the condition.\n\nWolff-Parkinson-White syndrome often occurs with other structural abnormalities of the heart or underlying heart disease. The most common heart defect associated with the condition is Ebstein anomaly, which affects the valve that allows blood to flow from the right atrium to the right ventricle (the tricuspid valve). Additionally, the heart rhythm problems associated with Wolff-Parkinson-White syndrome can be a component of several other genetic syndromes, including hypokalemic periodic paralysis (a condition that causes episodes of extreme muscle weakness), Pompe disease (a disorder characterized by the storage of excess glycogen), Danon disease (a condition that weakens the heart and skeletal muscles and causes intellectual disability), and tuberous sclerosis complex (a condition that results in the growth of noncancerous tumors in many parts of the body).

Aortic valve disease-2 (AOVD2) is characterized by bicuspid aortic valve (BAV) and dilation of the ascending aorta. Calcification of the valve and the aorta has been observed, and some patients exhibit coarctation of the aorta (Tan et al., 2012; Luyckx et al., 2019; Park et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of aortic valve disease, see AOVD1 (109730).

A form of anomalous pulmonary venous return in which not all pulmonary veins drain abnormally. Partial anomalous pulmonary venous return frequently involves one or both of the veins from one lung.

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 congenital malformation with abnormal connection between one of the coronary arteries and a heart chamber or another blood vessel.

Thickening of the heart walls in both ventricles.

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).

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

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 type of abnormal location of the ears in which the position of the ears is characterized by posterior rotation (the superior part of the ears is rotated towards the back of the head, and the inferior part of the ears towards the front).

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

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.

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.

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

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.

Parietal bossing is a marked prominence in the parietal region.

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

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).

A splitting of the nasal tip. Visually assessable vertical indentation, cleft, or depression of the nasal tip.

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).

Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip).

A marked tapering of the lower face to the chin.

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

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

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).

A gap in the lip or lips.

Abnormally increased hair growth referring to a male pattern of body hair (androgenic hair).