Ehlers-Danlos syndrome, classic type (Ehlers-Danlos syndrome type 1, Ehlers-Danlos syndrome type 2)
Incidence
Transmission of classical EDS is autosomal dominant. 1 in 5,000 live births.
Clinical Characteristics
Ehlers-Danlos syndromes (EDS) are a group of heterogenous inherited connective tissue disorders. The new classification defines six clinical forms, among which the so-called 'classical type' comprises former EDS types I and II. Major clinical diagnostic criteria are hyperextensible skin and joints, and atrophic cutaneous scars due to tissue fragility. Pattern of manifestations in types I-III including lax joints, hyperelastic skin, unusual "cigarette paper" scarring, and skin fragility. Examination may elicit Méténier's sign (easy eversion of upper lids) or Gorlin's sign (touching nose with tip of tongue). Other minor manifestations include astheny, molluscoid tumors, subcutaneous spheroids, joint (sub)luxations, muscular hypotony, and a family history of the disease. Very frequent signs include: eczema, striae, lordosis, flat foot, scoliosis, thin skin, arachnodactyly, shagreen patch, inguinal hernia, triangular face, pectus carinatum, umbilical hernia, hyperelastic skin, joint dislocation, purpura/petichiae, emphysema/lung cyst, glaucoma/buphthalmos, spina bifida occulta, talipes-varus/valgus, vascular hypertension, aortic root dilatation, hyperextensible joints, long/large/bulbous nose, high vaulted/narrow palate, prominent premaxillary region, tongue/gingiva/mucosa anomalies, long foot/arachnodactyly of toes. Frequent signs are the following: narrow face, prematurity, ear cartilage deficiency, mitral valve prolapse/incompetence. The following are occasional signs seen: myopia, kiphosis, broad nose, keratoconus, microcornea, microdontia, blue sclerae, long rib cage, dislocated lens, epicanthic folds, overlapping toes, retinal detachment, renal tubular defect, anodontia/oligodontia, short stature/dwarfism, auricular septal defect, abnormal dental position, wasted/poorly muscled build, mental retardation(degree not assessed). Transmission of classical EDS is autosomal dominant. The clinical diagnosis can be confirmed biochemically in these rare families by biochemical studies of collagen V secretion in cultured skin fibroblasts and by molecular studies.
Precipitants
none
Provocation Tests
none
Diagnostic Procedures
The clinical diagnosis can be confirmed biochemically in these rare families by biochemical studies of collagen V secretion in cultured skin fibroblasts and by molecular studies. Several types of Ehlers-Danlos syndrome have been related to mutations in collagen genes, but DNA diagnosis is not routinely available.