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).

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

Lateral deviation of the great toe (i.e., in the direction of the little toe).

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.

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

Fingers that are disproportionately narrow (reduced girth) for the hand/foot size or build of the individual.

Abnormal increase in width of the distal region of the metacarpal bones.

Any of the middle phalanges with short and wide phalanx that tapers distally. Bullet-shaped phalanges lack the normal diaphyseal constriction.

Coxa vara includes all forms of decrease of the femoral neck shaft angle (the angle between the neck and the shaft of the femur) to less than 120 degrees.

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.

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.

The presence of chronic increased pressure in the systemic arterial system.

Premature ventricular contractions (PVC) or ventricular extrasystoles are premature contractions of the heart that arise in response to an impulse in the ventricles rather than the normal impulse from the sinoatrial (SA) node.

A congenital malformation of the aortic valve characterized by leaflet deformation.

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.

A height above that which is expected according to age and gender norms.

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).

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

Abnormally low body weight.

Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.

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.

Anterior malposition of the anus.

Cholesteatoma is a benign but potentially destructive growth consisting of keratinizing epithelium located in the middle ear and/or mastoid process. In cholesteatoma, a skin cyst grows into the middle ear and mastoid. The cyst is not cancerous but can erode tissue and cause destruction of the 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 bilateral type of conductive hearing impairment.

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.

Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation.

Moderate mental retardation is defined as an intelligence quotient (IQ) in the range of 35-49.

The corpus callosum is the largest fiber tract in the central nervous system and the major interhemispheric fiber bundle in the brain. Formation of the corpus callosum begins as early as 6 weeks' gestation, with the first fibers crossing the midline at 11 to 12 weeks' gestation, and completion of the basic shape by age 18 to 20 weeks (Schell-Apacik et al., 2008). Agenesis of the corpus callosum (ACC) is one of the most frequent malformations in brain with a reported incidence ranging between 0.5 and 70 in 10,000 births. ACC is a clinically and genetically heterogeneous condition, which can be observed either as an isolated condition or as a manifestation in the context of a congenital syndrome (see MOLECULAR GENETICS and Dobyns, 1996). Also see mirror movements-1 and/or agenesis of the corpus callosum (MRMV1; 157600). Schell-Apacik et al. (2008) noted that there is confusion in the literature regarding radiologic terminology concerning partial absence of the corpus callosum, where various designations have been used, including hypogenesis, hypoplasia, partial agenesis, or dysgenesis.

Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum.

A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months.

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

Underdevelopment of the corpus callosum.

Absence of the septum pellucidum (meaning translucent wall in Latin - SP), also known as the ventricle of Sylvius. The septum pellucidum is a thin, triangular double membrane separating the frontal horns of the right and left lateral ventricles of the brain. It extends between the anterior portion of the corpus callosum, and the body of the fornix and its width varies from 1.5 to 3.0 mm.

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

Obstructive sleep apnea is a common, chronic, complex disease associated with serious cardiovascular and neuropsychologic sequelae and with substantial social and economic costs (Palmer et al., 2003).

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.

Compression of the spinal cord in the cervical region, generally manifested by paresthesias and numbness, weakness, difficulty walking, abnormalities of coordination, and neck pain or stiffness.

A type of Developmental delay characterized by a delay in acquiring motor skills.

Tendon reflexes that are noticeably more active than usual (conventionally denoted 3+ on clinical examination). Brisk reflexes may or may not indicate a neurological lesion. They are distinguished from hyperreflexia by the fact that hyerreflexia is characterized by hyperactive repeating (clonic) reflexes, which are considered to be always abnormal.

An increase in size of the ventricular system of the brain.

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.

Pachygyria is a malformation of cortical development with abnormally wide gyri with sulci 1,5-3 cm apart and abnormally thick cortex measuring more than 5 mm (radiological definition). See also neuropathological definitions for 2-, 3-, and 4-layered lissencephaly.

Craniosynostosis refers to the premature closure of the cranial sutures. Primary craniosynostosis refers to the closure of one or more sutures due to abnormalities in skull development, and secondary craniosynostosis results from failure of brain growth.

The repeated occurrence of bone fractures (implying an abnormally increased tendency for fracture).

Protrusion of abdominal contents through a defect in the abdominal wall musculature around the umbilicus. Skin and subcutaneous tissue overlie the defect.

Exaggerated anterior convexity of the thoracic vertebral column.

A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move.

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.

An abnormality in which the mandible is mislocalised posteriorly.

The presence of an abnormal lateral curvature of the spine.

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

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.

Partial dislocation of the atlantoaxial joint.

An abnormally increased rate of skeletal maturation. Accelerated skeletal maturation can be diagnosed on the basis of an estimation of the bone age from radiographs of specific bones in the human body.

An abnormal curvature of the spine in both a coronal (lateral) and sagittal (back-to-front) plane.

Decreased inferosuperior length of the sternum.

An omphalocele is an abdominal wall defect limited to an open umbilical ring, and is characterized by the herniation of membrane-covered internal organs into the open base of the umbilical cord. Omphalocele is distinguished from gastroschisis (230750), in which the abdominal wall defect is located laterally to a normally closed umbilical ring with herniation of organs that are uncovered by membranes (summary by Bugge, 2010). On the basis of clinical manifestations, epidemiologic characteristics, and the presence of additional malformations, Yang et al. (1992) concluded that omphalocele and gastroschisis are casually and pathogenetically distinct abdominal wall defects. Omphalocele can be a feature of genetic disorders, such as Beckwith-Wiedemann syndrome (130650) and the Shprintzen-Goldberg syndrome (182210).

Over curvature of the thoracic region, leading to a round back or if sever to a hump.

Reduced diameter of a long bone.

Reduced ability to move the femur outward to the side.

A form of developmental hypoplasia of the mandible in which the mandible is mislocalised posteriorly.

The odontoid process, or dens, is a bony projection from the axis (C2) upward into the ring of the atlas (C1) at the top of the spine. During embryogenesis, the body of the odontoid derives from the centrum of the atlas and separates from the atlas, fusing with the superior portion of the axis. If the odontoid is hypoplastic or absent, the attachments for the apical and alar ligaments are missing, allowing for excessive rotation of the atlas, craniocervical instability, and possibly cord compression (summary by Stevens et al., 2009).

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

Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.

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.

Prominent positioning of the premaxilla in relation to the rest of the maxilla, the facial skeleton, or mandible. Not necessarily caused by an increase in size (hypertrophy of) the premaxilla.

The presence of extra bones within a cranial suture. Wormian bones are irregular isolated bones which appear in addition to the usual centers of ossification of the cranium.

Congenital dysplasia of the hip (CDH) is an abnormality of the seating of the femoral head in the acetabulum. Its severity ranges from mild instability of the femoral head with slight capsular laxity, through moderate lateral displacement of the femoral head, without loss of contact of the head with the acetabulum, up to complete dislocation of the femoral head from the acetabulum. It is one of the most common skeletal congenital anomalies (summary by Sollazzo et al., 2000). Acetabular dysplasia is an idiopathic, localized developmental dysplasia of the hip that is characterized by a shallow hip socket and decreased coverage of the femoral head. Its radiologic criteria include the center-edge angle of Wiberg, the Sharp angle, and the acetabular roof obliquity. Most patients with acetabular dysplasia develop osteoarthritis (165720) after midlife, and even mild acetabular dysplasia can cause hip osteoarthritis (summary by Mabuchi et al., 2006). CDH occurs as an isolated anomaly or with more general disorders represented by several syndromes and with chromosomal abnormalities such as trisomy 18 (Wynne-Davies, 1970). Genetic Heterogeneity of Developmental Dysplasia of the Hip Developmental dysplasia of the hip-1 (DDH1) maps to chromosome 13q22; DDH2 (615612) maps to chromosome 3p21. DDH3 (620690) is caused by mutation in the LRP1 gene (107770) on chromosome 12q13.

Obstruction of conducting airways of the lung.

Lack of breathing with no movement of the respiratory muscles and no exchange of air in the lungs. This term refers to a disposition to have recurrent episodes of apnea rather than to a single event.

Stridor is a high pitched sound resulting from turbulent air flow in the upper airway.

Laryngomalacia is a congenital abnormality of the laryngeal cartilage in which the cartilage is floppy and prolapses over the larynx during inspiration.

An increased susceptibility to upper respiratory tract infections as manifested by a history of recurrent upper respiratory tract infections (running ears - otitis, sinusitis, pharyngitis, tonsillitis).

Pneumonia due to the aspiration (breathing in) of food, liquid, or gastric contents into the upper respiratory tract.

Increased susceptibility to aspiration pneumonia, defined as pneumonia due to breathing in foreign material, as manifested by a medical history of repeated episodes of aspiration pneumonia.

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.

Habitual flow of saliva out of the mouth.

An abnormally increased height of the forehead.

Decreased size of the teeth, which can be defined as a mesiodistal tooth diameter (width) more than 2 SD below mean. Alternatively, an apparently decreased maximum width of tooth.

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).

Posterior displacement of the tongue into the pharynx, i.e., a tongue that is mislocalised posteriorly.

Hyperplasia of the gingiva (that is, a thickening of the soft tissue overlying the alveolar ridge. The degree of thickening ranges from involvement of the interdental papillae alone to gingival overgrowth covering the entire tooth crown.

Abnormal narrowing of the choana (the posterior nasal aperture).

Facial contour, as viewed from the front, triangular in shape, with breadth at the temples and tapering to a narrow chin.

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.

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).

Width of the forehead or distance between the frontotemporales is more than two standard deviations above the mean (objective); or apparently increased distance between the two sides of the forehead.

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

Increased density/number and/or increased diameter of eyebrow hairs.

Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip.

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.

Increased height of the central portion of the eyebrow, forming a crescent, semicircular, or inverted U shape.

A turning outward of the lip or lips, that is, eversion of the lips.

Hypertrichosis is increased hair growth that is abnormal in quantity or location.

A oval and round, colored (usually medium-to dark brown, reddish brown, or flesh colored) lesion. Typically, a melanocytic nevus is less than 6 mm in diameter, but may be much smaller or larger.

Fragile, easily breakable hair, i.e., with reduced tensile strength.

Meeting of the medial eyebrows in the midline.

A soft tissue prominence of the ventral aspects of the fingertips. The term "persistent fetal fingertip pads" is often used as a synonym, but should better not be used because it implies knowledge of history of the patient which often does not exist.

Reduced density of hairs.

An eye that is protruding anterior to the plane of the face to a greater extent than is typical.

Glaucoma refers loss of retinal ganglion cells in a characteristic pattern of optic neuropathy usually associated with increased intraocular pressure.

Nearsightedness, also known as myopia, is an eye condition that causes blurry distance vision. People who are nearsighted have more trouble seeing things that are far away (such as when driving) than things that are close up (such as when reading or using a computer). If it is not treated with corrective lenses or surgery, nearsightedness can lead to squinting, eyestrain, headaches, and significant visual impairment.\n\nNearsightedness usually begins in childhood or adolescence. It tends to worsen with age until adulthood, when it may stop getting worse (stabilize). In some people, nearsightedness improves in later adulthood.\n\nFor normal vision, light passes through the clear cornea at the front of the eye and is focused by the lens onto the surface of the retina, which is the lining of the back of the eye that contains light-sensing cells. People who are nearsighted typically have eyeballs that are too long from front to back. As a result, light entering the eye is focused too far forward, in front of the retina instead of on its surface. It is this change that causes distant objects to appear blurry. The longer the eyeball is, the farther forward light rays will be focused and the more severely nearsighted a person will be.\n\nNearsightedness is measured by how powerful a lens must be to correct it. The standard unit of lens power is called a diopter. Negative (minus) powered lenses are used to correct nearsightedness. The more severe a person's nearsightedness, the larger the number of diopters required for correction. In an individual with nearsightedness, one eye may be more nearsighted than the other.\n\nEye doctors often refer to nearsightedness less than -5 or -6 diopters as "common myopia." Nearsightedness of -6 diopters or more is commonly called "high myopia." This distinction is important because high myopia increases a person's risk of developing other eye problems that can lead to permanent vision loss or blindness. These problems include tearing and detachment of the retina, clouding of the lens (cataract), and an eye disease called glaucoma that is usually related to increased pressure within the eye. The risk of these other eye problems increases with the severity of the nearsightedness. The term "pathological myopia" is used to describe cases in which high myopia leads to tissue damage within the eye.

A severe form of myopia with greater than -6.00 diopters.

Underdevelopment of the optic nerve.

An abnormal bluish coloration of the sclera.