Genetic diseases



homogentisuria photo homogentisuria - it is a rare genetic disorder that develops as a result of an absolute deficiency of the enzyme homogentisic acid, shown in black urine output.This disease is characterized by disorder of tyrosine metabolism, resulting in a homogentisic acid in urine is released in very large quantities.

homogentisuria adults often manifested centers pigmentation on the various organs and tissues are often observed the development of osteoarthritis.This is due to the fact that a congenital deficiency of the enzyme gomogentizinazy results in its accumulation in various tissues, often in the articular cartilage and tendons.The mental and physical development of people with this disease is absolutely not affected.

homogentisuria being a congenital systemic disease is very rare - 1 in 25,000 people, while having strong enough to bind to a specific geographic area of ​​the Dominican Republic, and Slovakia.This disease is directly linked to the breach of amino acid metabolism, inhe

rited recessive type.The exchange function of tyrosine subsequently comes exclusively to the stage of homogentisic acid.After that, due to the inherent lack of acid oxidase (an enzyme that breaks down the benzene ring of homogentisic acid), further transformation occurs, and accumulates in the sclera, cartilage, bone, skin and other organs, and then excreted in the urine.

homogentisuria a child is diagnosed shortly after birth - in the urine soaked diapers due to the release of large amounts of homogentisic acid are dark spots neotstiryvayuschiesya.

homogentisuria reasons

main cause of this disease is considered mutation processes in the genes responsible for the production of homogentisic oxidase, which helps splitting amino acids phenylalanine and tyrosine.As a result of these disorders in humans occurs accumulation of homogentisic acid.In most cases, the surplus, as well as a plethora of other compounds, is deposited in connective tissue, thereby causing blackening of the skin and cartilage.

also present a gradual accumulation of homogentisic acid in the joints, leading to the development of arthritis.Furthermore the substance in large amounts excreted in the urine secreted, which therefore in contact with air darkens considerably.

homogentisuria symptoms

The earliest and most characteristic feature is homogentisuria urine, which after interaction with the air very quickly darkens.In the future, often develops complicated pyelonephritis urolithiasis.It is also a characteristic feature of this disease is defeated spine and large joints, which in its clinical picture very similar chondrosis and ankylosing spondylitis.

For homogentisuria also characterized the following symptoms: change and pigmentation of the skin and sclera, limitation of movement, calcification, inflammation, destruction of articular cartilage, mechanical pain.Approximately 20% of patients present changes in the aortic valve, there is calcification of the ascending portion of the aorta and flaps as well as the fibrous ring.

By nesustavnym homogentisuria symptoms include pigmentation triangular groin, armpits, nose, sclera;calcification, and a bluish color of the outer ear.Heart murmurs may appear due to pigment deposition in the valve.Men are often found in the prostate gland stones.

Usually on the fourth decade of life in homogentisuria develops symptoms of progressive degenerative arthropathy.In this case, it marked the defeat large peripheral joints and spine with chondrocalcinosis (development of osteochondral bodies).Initial deposits pigment studinistom observed in the nucleus and the fibrous ring of intervertebral discs.Somewhat later involved the hip, shoulder and knee joints.The defeat of the small peripheral joints is observed.The first sign of spondylosis in adults is usually an acute syndrome disk clinically resembles ankylosing spondylitis.

addition at homogentisuria often identified quite severe functional impairment commonly associated with limited mobility and stiffness of the joints.Often found in the knee joint effusion, flexion contractures, crepitus.In some cases, the synovial fluid found fragments dark pigmented cartilage.

Diagnostics homogentisuria usually presents no difficulties.Most often, this disease can be diagnosed shortly after birth.All urine-soaked diapers are not leaving, even after proper washing dark spots.In the absence of this distinctive feature, the most informative diagnostic method is a method of determining the presence of an equivalent quantity in the urine and benzohinouksusnoy gomogentezinovoy acids.To obtain these results using enzymatic spectrophotometry and / or liquid chromatography.A very important point is to carry out the differential diagnosis with melaninuriey, porphyria, hemoglobinuria, hematuria, and a deficiency of vitamin C.

homogentisuria treatment

Unfortunately, at present a specific treatment homogentisuria not developed.In most cases, after a comprehensive survey shows a strict symptomatic therapy.In diseases of the musculoskeletal system recommended anti-inflammatory drugs, in urolithiasis is shown receiving antispasmodics, etc.It is mandatory intake of vitamin C in large doses.

Because of the genetic nature of homogentisuria develop specific preventive measures is not possible.

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