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).

Vesicoureteral reflux (VUR) is characterized by the reflux of urine from the bladder into the ureters and sometimes into the kidneys. It is a risk factor for urinary tract infections. Primary VUR results from a developmental defect of the ureterovesical junction (UVJ). In combination with intrarenal reflux, the resulting inflammatory reaction may result in renal injury or scarring, also called reflux nephropathy (RN). Extensive renal scarring impairs renal function and may predispose patients to hypertension, proteinuria, and renal insufficiency (summary by Lu et al., 2007). Genetic Heterogeneity of Vesicoureteral Reflux A locus designated VUR1 maps to chromosome 1p13. VUR2 (610878) is caused by mutation in the ROBO2 gene (602431) on chromosome 3p12; VUR3 (613674) is caused by mutation in the SOX17 gene (610928) on chromosome 8q11; VUR4 (614317) maps to chromosome 5; VUR5 (614318) maps to chromosome 13; VUR6 (614319) maps to chromosome 18; VUR7 (615390) maps to chromosome 12; and VUR8 (615963) is caused by mutation in the TNXB gene (600985) on chromosome 6p21. A possible X-linked form has been reported (VURX; 314550).

A connection of the right and left kidney by an isthmus of functioning renal parenchyma or fibrous tissue that crosses the midline.

A developmental defect in which a kidney is located in an abnormal anatomic position.

A unilateral form of agenesis of the kidney.

Hypoplasia of the kidney.

A genital phenotype that is not clearly assignable to a single gender. Ambiguous genitalia can be evaluated using the Prader scale

Agenesis, that is, failure of the kidney to develop during embryogenesis and development.

A reduction in the level of performance of the kidneys in areas of function comprising the concentration of urine, removal of wastes, the maintenance of electrolyte balance, homeostasis of blood pressure, and calcium metabolism.

A lack of differentiation between renal cortex and medulla on diagnostic imaging.

A reduction in the count of nephrons per kidney.

An increase in amplitude of waves returned in ultrasonography of the kidney, which is generally displayed as increased brightness of the signal.

The presence of developmental dysplasia of the kidney.

Incomplete duplication of the ureter.

Abnormally small penis. At birth, the normal penis is about 3 cm (stretched length from pubic tubercle to tip of penis) with micropenis less than 2.0-2.5 cm.

Abnormal outpouching or sac-like dilatation in the wall of an atery, vein or the heart.

Any structural anomaly of the heart.

A deficiency or slowing down of growth pre- and postnatally.

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

Underdevelopment of the external 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.

An abnormality of the pinna, which is also referred to as the auricle or external ear.

A decreased magnitude of the sensory perception of sound.

Increased thickness of the helix of the ear.

Underdevelopment of the helix, i.e., of the outer rim of the pinna.

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.

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

The presence of a hernia of the diaphragm present at birth.

Generalized muscular hypotonia (abnormally low muscle tone).

Impairment of gas exchange within the lungs secondary to a disease process, neoplasm, or trauma, possibly resulting in hypoxia, hypercarbia, or both, but not requiring intubation or mechanical ventilation. Patients are normally managed with pharmaceutical therapy, supplemental oxygen, or both.

An abnormal morphology (form) of the face or its components.

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).

Facial height (length) is more than 2 standard deviations above the mean (objective); or, an apparent increase in the height (length) of the face (subjective).

Bizygomatic (upper face) and bigonial (lower face) width are both more than 2 standard deviations below the mean (objective); or, an apparent reduction in the width of the upper and lower face (subjective).

Accentuated, prominent philtral ridges giving rise to an exaggerated groove in the midline between the nasal base and upper vermillion border.

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).

Increased breadth of the nasal bridge (and with it, the nasal root).

Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective).

Diminished amniotic fluid volume in pregnancy.

A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error.