DESMOGENEZ IMPERFECT (desmogenesis imperfecta; grech, desmos leash, sheaf + genesis origin, education; synonym: withutis hyperelastica, cutis laxa, dermatolysis diffusa, fibrodysplasia elastica, dermatorhexis, Elers's syndrome — Danlosa) — the disease, to-rogo is the cornerstone inborn disturbance of development of collagenic structures in various bodies. Has family, hereditary character. On this sign of D. of N it is possible to consider an analog of imperfect bone formation (see. Bone formation imperfect ) and an imperfect chondrogenesis (see. Chondrogenesis imperfect ). Of N is included into a triad of processes of disturbance of formation of interstitial substance. The disease was for the first time described by A. Chernogubov in 1892. The term «desmogenez imperfect» entered by A. V. Rusakov in the 50th precisely reflects essence of process. Being dysplastic process, D. of N can be combined with disturbances of development of a skull, backbone, inborn heart diseases, neurofibromatosis (see), changes of muscles of type of inborn myatonias (see) etc.
At microscopic examination sharp reduction of amount of collagenic fibers in skin, ligaments, vessels, internals is found. Most sharply it is expressed in skin. The derma is thin, its structure is considerably simplified, the number of collagenic fibers is sharply reduced, fibers do not develop in bunches or bunches do not form a difficult interlacing inherent to them. Weak communication of skin with hypodermic cellulose causes the raised smeshchayemost of skin. Data light and a submicroscopy confirm a usual structure of collagenic fibers, however homogenization, myxomatous hypostasis, fragmentation, their disintegration on thin fibrilla are sometimes observed. Along with insufficient amount of collagenic fibers the hyperelastosis takes place. Chemical and physical. properties of collagenic and elastic fibers are opposite: collagen chemically labilen, and is mechanically very steady, elastic fibers are chemically exclusively steady, and are mechanically extremely fragile. Normal elastic fibers exist in an environment of the inextensible collagenic fibers protecting them from mechanical influences. At D. of N elastic fibers are deprived of this support and are easily torn. The hyperelastosis is especially expressed in places of a bigger smeshchayemost and in a nek-swarm of degree compensates a lack of collagenic fibers. Reduction of mechanical strength of internals at D. the N allows to assume underdevelopment and the argyrophil fibers making a considerable part of their basic fabric. Changes in vessels of different caliber and different areas of a body are expressed unequally.
The main signs of D. of N — sharp redistensibility and vulnerability of skin, weakness of sheaves, looseness of joints, easy vulnerability of vessels. E.g., delaying skin of a shoulder, the patient can cover with it a cinciput. The delayed skin easily is returned to the initial position. At the slightest injuries there are gaps and even separations of rags of skin.
Wounds and ulcers heal inertly with formation of the defective, thin, easily torn hems. In places, the most subject to mechanical influences (to area of knee and elbow joints, skin of shins), there are multiple hems which are an important diagnostic character. Under skin in points of pressure (knees, heels, elbows) the pseudoneoplasms representing a nekrotizirovanny fatty tissue or as A. V. Rusakov considered are formed lymphangiectasias (see), the scarrings of hypodermic gaps which are formed in the place. Seams on wounds of skin, on internals, on vessels are easily cut through. Weakness of sheaves causes looseness of joints, W. h a backbone, with a range of movements which is far surpassing fiziol, norms. The patient described by A. V. Rusakov, having bent a backbone of a kzada and having passed the head between knees, could lift language from a floor a needle («rubber», «gutta-percha» people). At such patients dislocations and incomplete dislocations of joints are frequent. N lead spontaneous ruptures of walls of vessels at D. to formation of hematomas in skin, muscles, internals, are the reason of profuse puerperal, gastric bleedings, hematencephalons, and the rupture of large vessels (renal, subclavial arteries) leads to fatal bleedings. The stratifying aneurisms, spontaneous ruptures of an aorta, lungs, intestines are described.
The diagnosis is based on specific displays of a disease and difficulties usually does not present.
Of N lasts all life, is followed by complications which can lead to a lethal outcome.
Some lines of D. of N (the torn skin, fragility of vascular walls, hems) can be acquired as a result of the long debilitating diseases which are followed by big losses of proteins. This form D. of N is reversible after performing the corresponding treatment.
Inborn D.'s treatment N is directed to fight against complications which prevention consists in elimination physical. retension.
Bibliography: Badalyan L. O., Tabolin V. A. and Veltishchev Yu. E. Hereditary diseases at children, M., 1971; Zverkova F. A. and Kachanov V. P. About Elers's syndrome — Danlosa, Vestn, dermas, and veins., No. 2, page 47, 1976; Kosin-skayan. C. Disturbances of development of the kostnosustavny device, page 30, 115, L., 1966; A. V. K Hares of physiology and pathology of some fabrics of internal environment (Imperfect desmogenez), M., 1954, bibliogr.; Heilmann K. M, NemetschekT. u. V 1 k 1 A. Das Ehlers — Danlos — Syndrom aus morpholo-gischer und chemischer Sicht, Virchows Arch. path. Anat., Bd 354, S. 268, 1971; McKusick V. A. Heritable disorders of connective tissue, St Louis, 1972.
T. P. Vinogradova.