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).

Abnormal position of urethral meatus on the ventral penile shaft (underside) characterized by displacement of the urethral meatus from the tip of the glans penis to the ventral surface of the penis, scrotum, or perineum.

An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age.

A kind of short stature in which different regions of the body are shortened to a comparable extent.

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

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

A febrile seizure is any type of seizure (most often a generalized tonic-clonic seizure) occurring with fever (at least 38 degrees Celsius) but in the absence of central nervous system infection, severe metabolic disturbance or other alternative precipitant in children between the ages of 3 months and 6 years.

Abnormal coordination of muscles involved in speech.

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

Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior.

Impairment of certain skills such as reading or writing, coordination, self-control, or attention that interfere with the ability to learn. The impairment is not related to a global deficiency of intelligence.

A reduction in erythrocytes volume or hemoglobin concentration.

An abnormal reduction in numbers of all blood cell types (red blood cells, white blood cells, and platelets).

Protrusion of the contents of the abdominal cavity through the inguinal canal.

Absence of one half of the vertebral body.

An increased susceptibility to bronchitis as manifested by a history of recurrent bronchitis.

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.

Eczema is a form of dermatitis that is characterized by scaly, pruritic, erythematous lesions located on flexural surfaces.

An allergy is an immune response or reaction to substances that are usually not harmful.

Failure of the immune system to protect the body adequately from infection, due to the absence or insufficiency of some component process or substance.

Increased susceptibility to infections.

Increased susceptibility to otitis media, as manifested by recurrent episodes of otitis media.

Increased susceptibility to herpesvirus, as manifested by recurrent episodes of herpesvirus.

Periodic (episodic or recurrent) bouts of fever.

The palpebral fissure inclination is more than two standard deviations below the mean.

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.

Inability to sweat.

Petechiae are pinpoint-sized reddish/purple spots, resembling a rash, that appear just under the skin or a mucous membrane when capillaries have ruptured and some superficial bleeding into the skin has happened. This term refers to an abnormally increased susceptibility to developing petechiae.

Skin characterized by the lack of natural or normal moisture.

Laminar thickening of skin.

Development of gray hair at a younger than normal age.

A lesser degree of hair pigmentation than would otherwise be expected.

A reduced ability to heal cutaneous wounds.