MedGen

Progressive damage to mitochondrial DNA (mtDNA) during life is thought to contribute to aging processes. This notion is supported by the observation of an aging-related accumulation in human mtDNA of oxidative and alkylation derivatives of nucleotides, of small deletions and insertions, and of large deletions, although their low frequency raises questions about their functional significance (Michikawa et al., 1999). [from OMIM]

An autosomal recessive inherited skin disorder caused by mutations in the genes encoding keratins 5 and 14, collagen VII or laminin 5. It is characterized by skin fragility and the formation of blisters. The blisters may become large and ulcerated, resulting in skin infections and loss of body fluids. [from NCI]

Dystrophic epidermolysis bullosa (DEB) is a genetic skin disorder affecting skin and nails that usually presents at birth. DEB is divided into two major types depending on inheritance pattern: recessive dystrophic epidermolysis bullosa (RDEB) and dominant dystrophic epidermolysis bullosa (DDEB). Each type is further divided into multiple clinical subtypes. Absence of a known family history of DEB does not preclude the diagnosis. Clinical findings in severe generalized RDEB include skin fragility manifest by blistering with minimal trauma that heals with milia and scarring. Blistering and erosions affecting the whole body may be present in the neonatal period. Oral involvement may lead to mouth blistering, fusion of the tongue to the floor of the mouth, and progressive diminution of the size of the oral cavity. Esophageal erosions can lead to webs and strictures that can cause severe dysphagia. Consequently, malnutrition and vitamin and mineral deficiency may lead to growth restriction in young children. Corneal erosions can lead to scarring and loss of vision. Blistering of the hands and feet followed by scarring fuses the digits into "mitten" hands and feet, with contractures and pseudosyndactyly. The lifetime risk of aggressive squamous cell carcinoma is higher than 90%. In contrast, the blistering in the less severe forms of RDEB may be localized to hands, feet, knees, and elbows with or without involvement of flexural areas and the trunk, and without the mutilating scarring seen in severe generalized RDEB. In DDEB, blistering is often mild and limited to hands, feet, knees, and elbows, but nonetheless heals with scarring. Dystrophic nails, especially toenails, are common and may be the only manifestation of DDEB. [from GeneReviews]

Dystrophic epidermolysis bullosa (DEB) is a genetic skin disorder affecting skin and nails that usually presents at birth. DEB is divided into two major types depending on inheritance pattern: recessive dystrophic epidermolysis bullosa (RDEB) and dominant dystrophic epidermolysis bullosa (DDEB). Each type is further divided into multiple clinical subtypes. Absence of a known family history of DEB does not preclude the diagnosis. Clinical findings in severe generalized RDEB include skin fragility manifest by blistering with minimal trauma that heals with milia and scarring. Blistering and erosions affecting the whole body may be present in the neonatal period. Oral involvement may lead to mouth blistering, fusion of the tongue to the floor of the mouth, and progressive diminution of the size of the oral cavity. Esophageal erosions can lead to webs and strictures that can cause severe dysphagia. Consequently, malnutrition and vitamin and mineral deficiency may lead to growth restriction in young children. Corneal erosions can lead to scarring and loss of vision. Blistering of the hands and feet followed by scarring fuses the digits into "mitten" hands and feet, with contractures and pseudosyndactyly. The lifetime risk of aggressive squamous cell carcinoma is higher than 90%. In contrast, the blistering in the less severe forms of RDEB may be localized to hands, feet, knees, and elbows with or without involvement of flexural areas and the trunk, and without the mutilating scarring seen in severe generalized RDEB. In DDEB, blistering is often mild and limited to hands, feet, knees, and elbows, but nonetheless heals with scarring. Dystrophic nails, especially toenails, are common and may be the only manifestation of DDEB. [from GeneReviews]

The presence of squamous cell carcinoma of the skin. [from HPO]

Squamous cell carcinoma of the skin is a malignant tumor of squamous epithelium. [from HPO]

A finding of a localized protective response resulting from injury or destruction of tissues. Inflammation serves to destroy, dilute, or wall off both the injurious agent and the injured tissue. In the acute phase, inflammation is characterized by the signs of pain, heat, redness, swelling, and loss of function. Histologically, inflammation involves a complex series of events, including dilatation of arterioles, capillaries, and venules, with increased permeability and blood flow; exudation of fluids, including plasma proteins; and leukocyte migration into the site of inflammation. [from NCI]

The formation of fibrous tissue. [from NCI]

A malignant tumor arising from epithelial cells. Carcinomas that arise from glandular epithelium are called adenocarcinomas, those that arise from squamous epithelium are called squamous cell carcinomas, and those that arise from transitional epithelium are called transitional cell carcinomas (NCI Thesaurus). [from HPO]

A tumor (abnormal growth of tissue) of the skin. [from HPO]

Skin that splits easily with minimal injury. [from HPO]

A neoplasm that is composed of squamous epithelial cells. Squamous cell carcinoma is a representative example. [from NCI]

A usually aggressive malignant epithelial neoplasm composed of atypical cells which do not display evidence of glandular, squamous, or transitional cell differentiation. [from NCI]

A non-neoplastic or neoplastic disorder that affects the connective tissue. [from NCI]

Diseases that are caused by genetic mutations present during embryo or fetal development, although they may be observed later in life. The mutations may be inherited from a parent''s genome or they may be acquired in utero. [from MeSH]

A benign or malignant neoplasm that arises from and is composed of epithelial cells. This category include adenomas, papillomas, and carcinomas [NCIT:C3709]. [from HPO]

Structural or functional abnormalities of the fetus. Note that this section comprises terms that describe abnormalities that are specific to the fetus or differ from the corresponding general terms. A term from anywhere in the Human Phenotype Ontology can be applied to a fetus if appropriate. [from HPO]

Inflammatory and degenerative diseases of connective tissue structures, such as arthritis. [from NCI]

Any deviation from the normal structure or function of the skin or subcutaneous tissue that is manifested by a characteristic set of symptoms and signs. [from NCI]

Skin diseases characterized by local or general distributions of blisters. They are classified according to the site and mode of blister formation. Lesions can appear spontaneously or be precipitated by infection, trauma, or sunlight. Etiologies include immunologic and genetic factors. (From Scientific American Medicine, 1990) [from MONDO]