A bacterial infection and inflammation of the skin und subcutaneous tissues.

Abnormally increased formation of dense trabecular bone tissue. Despite the increased density of bone tissue, osteopetrotic bones tend to be more fracture-prone than normal.

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

Persistent abnormal dilatation of the bronchi owing to localized and irreversible destruction and widening of the large airways.

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

An increased susceptibility to lower respiratory tract infections as manifested by a history of recurrent lower respiratory tract infections.

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

A meningitis caused by viral infection, with common causative organisms including herpes simplex virus, varicella-zoster virus, enterovirus, and CMV. A recurrent or chronic viral meningitis (particularly chronic enteroviral meningoencephalitis) can be a manifestation of unusual susceptibility to infection.

Molluscum contagiosum is a cutaneous viral infection that is commonly observed in both healthy and immunocompromised children. The infection is caused by a member of the Poxviridae family, the molluscum contagiosum virus. Molluscum contagiosum presents as single or multiple small white or flesh-colored papules that typically have a central umbilication. The central umbilication may be difficult to observe in young children and, instead, may bear an appearance similar to an acneiform eruption. The lesions vary in size (from 1 mm to 1 cm in diameter) and are painless, although a subset of patients report pruritus in the area of infection. On average, 11-20 papules appear on the body during the course of infection and generally remains a self-limiting disease. However, in immunosuppressed patients, molluscum contagiosum can be a severe infection with hundreds of lesions developing on the body. Extensive eruption is indicative of an advanced immunodeficiency state.

Inflammation of any part of the lung parenchyma.

A meningitis caused by bacterial infection, with common causative organisms including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b. A recurrent or invasive bacterial meningitis with encapsulated organisms can be a manifestation of unusual susceptibility to infection, particularly in antibody deficiencies, complement deficiencies, and asplenia.

Decreased levels of immunoglobulin A (IgA).

An abnormally increased level of immunoglobulin A in blood.

A granulomatous inflammation leading to multiple granuloma formation, which is a specific type of inflammation. A granuloma is a focal compact collection of inflammatory cells, mononuclear cells predominating, usually as a result of the persistence of a non-degradable product and of active cell mediated hypersensitivity.

A cellulitis caused by bacterial infection of the dermis and subcutaneous tissue, with common causative organisms including Streptococcus pyogenes and Staphylococcus aureus.

An abnormally increased level of immunoglobulin M in blood.

Increased susceptibility to bacterial infections as manifested by recurrent episodes of bacterial infection.

An increased susceptibility to bacterial meningitis as manifested by a medical history of recurrent episodes of bacterial meningitis.

The absolute number of B cells in the blood, per microlitre is above the upper limit of normal of the reference range for the appropriate sex and age-group.

A reduction in immunoglobulin levels of the IgG2 subclass in the blood circulation.

An increased susceptibility to cutaneous abscess formation, as manifested by a medical history of recurrent cutaneous abscesses.

Abnormal response of natural killer (NK) cells to stimuli.

Abnormal decrease of neutrophil oxidative burst, commonly measured through oxidation of dihydrorhodamine (DHR) using flow cytometry or through nitroblue tetrazolium test (NBT) using optical microscopy, upon stimulation with phorbol-12-myristate-13-acetate (PMA), E. coli or other ligands.

A diminished activity of the classical complement pathway as measured by the assay for 50% haemolytic complement (CH50) activity of serum.

An abnormally decreased level of immunoglobulin G (IgG) in blood.

Abnormal decrease of T cell proliferation in response to mitogenic stimuli. This is commonly measured through intracellular expression of Ki67, decreasing surface expression of carboxyfluorescein diacetate (CFSE), or 3H-thymidine incorporation. Length of incubation, specific stimulus and strength of stimulation may vary between laboratories.

An unusually severe infection by cytomegalovirus.

An abnormal deviation from normal levels of IgE immunoglobulin in blood.

An abnormal deviation from normal levels of IgG immunoglobulin in blood.

An abnormal deviation from normal levels of IgM immunoglobulin in blood.

Absent or undetectable level of isohemagglutinin. An isohemagglutinin refers to the naturally occurring antibodies in the ABO blood group system (i.e., anti-A in a group B person, anti-B in a group A person, and anti-A, anti-B, and anti-A,B in a group O person).

A reduced ability to synthesize postvaccination antibodies against a tetanus antigen, as measured by antibody titer determination following vaccination.

The inability to synthesize postvaccination antibodies against a pneumococcus antigen, as measured by antibody titer determination following vaccination.

Repeated bouts of sepsis, defined as life-threatening organ dysfunction caused by a dysregulated host response to infection.

Increased susceptibility to Pseudomonas aeruginosa infections as manifested by a severe or invasive infection with Pseudomonas aeruginosa.

Increased susceptibility to mycobacterial infections as manifested by recurrent or severe/disseminated infection with mycobacterial organisms, including Mycobacterium tuberculosis, non-tuberculous mycobacteria (NTM), or BCG.

Increased susceptibility to Giardia lamblia infections as manifested by recurrent episodes of Giardia lamblia infection.

Increased susceptibility to osteomyelitis of infectious aetiology, as manifested by recurrent or severe bone infection, multifocal osteomyelitis, or osteomyelitis caused by an atypical or opportunistic organism.

Presence of viable bacteria in the blood.

Localized fluid retention and tissue swelling caused by a compromised lymphatic system.

Tooth agenesis in some form is a common human anomaly that affects approximately 20% of the population. Although tooth agenesis is associated with numerous syndromes, several case reports describe nonsyndromic forms that are either sporadic or familial in nature, as reviewed by Gorlin et al. (1990). The incidence of familial tooth agenesis varies with each class of teeth. Most commonly affected are third molars (wisdom teeth), followed by either upper lateral incisors or lower second premolars; agenesis involving first and second molars is very rare. Also see 114600 and 302400. Selective tooth agenesis without associated systemic disorders has sometimes been divided into 2 types: oligodontia, defined as agenesis of 6 or more permanent teeth, and hypodontia, defined as agenesis of less than 6 teeth. The number in both cases does not include absence of third molars (wisdom teeth). Faulty use of the terms, however, have confounded their use. The term 'partial anodontia' is obsolete (Salinas, 1978). Genetic Heterogeneity of Selective Tooth Agenesis Other forms of selective tooth agenesis include STHAG2 (602639), mapped to chromosome 16q12; STHAG3 (604625), caused by mutation in the PAX9 gene (167416) on chromosome 14q12; STHAG4 (150400), caused by mutation in the WNT10A gene (606268) on chromosome 2q35; STHAG5 (610926), mapped to chromosome 10q11; STHAG7 (616724), caused by mutation in the LRP6 gene (603507) on chromosome 12p13; STHAG8 (617073), caused by mutation in the WNT10B gene (601906) on chromosome 12q13; STHAG9 (617275), caused by mutation in the GREM2 gene (608832) on chromosome 1q43; STHAG10 (620173), caused by mutation in the TSPEAR gene (612920) on chromosome 21q22; and STHAGX1 (313500), caused by mutation in the EDA gene (300451) on chromosome Xq13. A type of selective tooth agenesis that was formerly designated STHAG6 has been incorporated into the dental anomalies and short stature syndrome (DASS; 601216). Of 34 unrelated patients with nonsyndromic tooth agenesis, van den Boogaard et al. (2012) found that 56% (19 patients) had mutations in the WNT10A gene (STHAG4), whereas only 3% and 9% had mutations in the MSX1 (STHAG1) and PAX9 (STHAG3) genes, respectively. The authors concluded that WNT10A is a major gene in the etiology of isolated hypodontia. Genotype-Phenotype Correlations Yu et al. (2016) observed that the most frequently missing permanent teeth in WNT10B-associated oligodontia were the lateral incisors (83.3%), whereas premolars were missing only 51.4% of the time, which they noted was a pattern 'clearly different' from the oligodontia patterns resulting from WNT10A mutations. They also stated that the selective pattern in WNT10B mutants was different from that associated with mutations in other genes, such as MSX1, in which second premolars are missing, and PAX9, in which there is agenesis of molars.

An abnormal conical form of the teeth, that is, a tooth whose sides converge or taper together incisally.

An abnormal conical morphology of the incisor tooth.

Decreased number of hairs per unit area of skin of the scalp.

An abnormality of the hair of head.

An abnormal conical morphology of the primary incisor.

A tooth crown with its mesial and distal sides converging or tapering toward the incisal edge causing severe reduction of mesiodistal diameter

Decreased density/number of eyebrow hairs.

Inability to sweat.

Ectodermal dysplasia is a group of conditions in which there is abnormal development of the skin, hair, nails, teeth, or sweat glands.

Abnormally diminished capacity to sweat.

Skin characterized by the lack of natural or normal moisture.

A reduction of skin color related to a decrease in melanin production and deposition.

Reduced density of hairs.