Ehler-Danlos syndrome

Introduction

Introduction to Eller-Danluo Syndrome Ehlers-Danlossyndrome (EDS) is also known as full-body elastic fiber dysplasia. Clinically, the skin and joints are overstretched, the tissue is easily damaged, the fragility is increased, the wound is not easy to heal, the vascular fragility is increased, the eye is abnormal and the internal organs are abnormal, and it is a collagen innate metabolic abnormality which is one of the main proteins of connective tissue. basic knowledge The proportion of illness: 0.005%-0.008% Susceptible people: no specific population Mode of infection: non-infectious Complications: congenital heart disease, mental retardation

Cause

Causes:

The etiology of the disease is not very clear at present, but it is generally believed to be caused by defects in the process of collagen transcription and translation caused by hypoplasia of mesoderm cells or by defects in various post-translation enzymes that make it difficult to synthesize.

Pathogenesis:

The pathogenesis of this disease is still not very clear, most of them have family history, and the incidence is mostly in line with autosomal dominant inheritance or autosomal recessive inheritance, and part of it is in line with X-linked recessive inheritance.

In recent years, due to the development of molecular biology and protein chemistry, the main components of extracellular matrix proteins and corresponding gene mutations have been identified. The application of new technologies, such as the use of transgenic animal models to observe the basic functions of matrix gene products, include Transcription factors, growth factors, differentiation factors and cytokines have made the study of the pathogenesis more in-depth. The current difficulty is to understand the relationship between specific gene mutations and clinical phenotypes, and the pathological mechanisms of mutations in order to formulate reasonable clinical treatment strategies.

Prevention

(1) Pre-marital examination: Pre-marital examination (i.e., marital health care) is an important link to ensure the happiness of both men and women after marriage and the health of offspring. The key points of pre-marital examination are:

① Investigation of genetic diseases, including detailed inquiries on the health status of both men and women and their family members, past medical history and medical treatment, especially the presence or absence of congenital malformations, hereditary medical history and consanguineous marriage history. Chromosomal testing or genetic diagnosis to detect carriers;

②Comprehensive physical examination, mainly for acute infectious diseases, tuberculosis, or severe heart, liver, kidney disease, chronic inflammation of the urinary tract and other diseases that can seriously threaten the health of the individual or spouse, as well as the woman's severe anemia, diabetes, etc. Detection of diseases affecting the fetus, and mobilization to be cured before marriage;

③ The examination of male and female reproductive organs can detect diseases such as genital malformation and hermaphroditism, so that measures can be taken as early as possible.

Complication

Elaire-Danlos Syndrome Complications Complications Congenital Heart Disease Intellectual Depression
1. Type I: Selective joint habitual dislocation, joint effusion, foot deformity, lumbar spine deformity, and venous aneurysm often occur.

2. Type III: It can be complicated with abnormal joints such as patella, shoulder, hip, and clavicle, combined with chronic dislocation.

3. Type IV: bleeding may be complicated, and death is often caused by arterial rupture or perforation of the digestive tract.

4. Type V: It can be complicated by bone and joint deformity and joint hematoma, and it is easy to combine with congenital heart disease, especially mitral valve prolapse.

5. Type IX: It is often complicated by severe mental retardation and the formation of hernia, such as umbilical hernia, indirect inguinal hernia, etc.

Symptom

Ehler-Danlos Syndrome Symptoms Common Symptoms Trauma Unresponsive Joint Deformities Pulmonary Stenosis Atrial Septal Defect Mitral Valve Prolapse Increased Skin Fragility
Often premature infants, often accompanied by early rupture of membranes, infants showed hypotonia.

1. The common features of this syndrome are

(1) The skin and blood vessels are fragile, and the skin is easily torn if it is slightly damaged, the wound healing is slow, the subcutaneous blood vessels are more fragile, and ecchymosis is easily formed in light injuries.

(2) The skin is overstretched, which can pull out very long skin folds. In old age, the skin sags, especially on the elbows, and the skin of the whole body becomes thinner.

(3) If the range of motion of the joints is too large, the patella, shoulder, hip, clavicle and temporomandibular joint are easily dislocated, and children with excessive joint movement are prone to fall. The patient can stretch automatically or passively.

(4) The beam arm test was positive.

(5) Often accompanied by secondary infection.

(6) Sometimes combined with cardiac malformations such as mitral valve prolapse, abnormal aortic arch, bivalve aortic valve, pulmonary stenosis, atrium, ventricular septal defect, tetralogy of Fallot, etc.

(7) Others: Various hernias can occur, such as umbilical hernia, indirect inguinal hernia, hiatal hernia, etc. Pulmonary lesions such as lung rupture, pneumothorax, emphysema, etc., dental caries or periodontitis can also occur.

2. This syndrome and its 11 subtypes are introduced as follows

(1) Type I: also known as Gravis type, the most common type, also known as severe type, and more common in premature infants. Since the fetal membranes are mainly from the fetus, the fragility of the connective tissue increases, so the fetal membranes rupture early, and the newborn may have congenital In children, due to excessive joint movement, it is difficult to control, and often falls. With the growth and development of children, selective joint habitual dislocation, joint effusion, foot deformity, lumbar deformity, and often venous aneurysm may occur.

(2) Type II: also known as Mitis type, this type is a mild type of type I. Hypermobility of the joints is common, and there may also be loose skin on the palms, often with wrinkles on the soles of the feet, increased skin fragility, and wound healing after trauma. Slow, this type has milder symptoms than type I.

(3) Type III: This type is also known as benign hypermobility type. This type is characterized by joint hypermobility, mainly manifested in abnormal joints such as patella, shoulder, hip, and clavicle, combined with chronic dislocation, and mild skin and bone deformities.

(4) Type IV: subcutaneous hemorrhage type, arterial type or Sack type, no skin hyperextension, but thin skin, can penetrate the subcutaneous reticular vein, easy to bleed, and often die due to arterial rupture or perforation of the digestive tract , rarely live to the age of 20, sometimes combined with a variety of congenital cardiovascular system abnormalities, including tetralogy of Fallot, atrial septal defect, pulmonary artery and aorta abnormalities, etc. This type of patients can develop aortic dissecting aneurysm, and Hemangiomas are prone to spontaneous rupture, and aortic root dilatation may also occur, resulting in aortic regurgitation.

(5) Type V: The symptoms of hyperextension of the skin are the same as those of type I, but the hypermobility of the joints is relatively mild and limited, and there are often bone and joint deformities and joint hematomas. Cubic valve prolapse is more common.

(6) Type VI: In addition to the above common features of this syndrome, there are also Marfan syndrome-like symptoms such as keratoconus, lens dislocation, retinal detachment, spider fingers, scoliosis, etc. Therefore, this type is also called Marfan-like hyperactivity syndrome.

(7) Type VII: also known as multi-joint laxity type, with multi-joint laxity as its main clinical manifestation, which may cause unresponsiveness.

(8) Type VIII: periodontitis type, patients with this type have increased skin fragility, are prone to post-traumatic hemorrhage, and hyperactive joints are limited to fingers. The clinical manifestations are characterized by periodontitis.

(9) Type IX: This type is mostly manifested as mental retardation. In addition to skin overstretching and increased skin fragility, there are many severe mental retardation and the formation of hernia, such as umbilical hernia and indirect inguinal hernia.

(10) Type Ⅹ: It is a type of platelet dysfunction. In addition to the common features of Ehler-Danlos syndrome, this type is specific for platelet aggregation dysfunction.

(11) Type XI: It is a type of joint laxity, which is characterized by hypermobility of the joints, especially shoulder dislocation.

In addition to the above symptoms, neuromuscular symptoms can also occur in Heller-Danlos syndrome, and central nervous system symptoms are mainly caused by intracranial aneurysms, such as severe subarachnoid hemorrhage caused by rupture of cerebral aneurysm, internal carotid artery cavernous Symptoms of compression caused by sinus fistulas, tortuosity of retinal blood vessels, proliferative retinitis or retinal detachment caused by dilation and grand mal seizures, etc., muscle symptoms include muscle dysplasia with muscle weakness, and muscle atrophy.

Examine

laboratory test

1. Hematological examination: patients with repeated gastrointestinal bleeding may have varying degrees of anemia, thrombocytopenia, abnormal coagulation factors and positive beam arm test.

2. Immunological examination: common IgA, IgG or IgM decreased and E-rosette formation decreased.

X-ray examination.

1. Display: There are scattered small round calcified nodules under the skin, and the two sides are often arranged symmetrically. The most common is on the extensor side of the limbs. The nodules of the lower limbs can be seen inside and outside. Surrounded by dense shadows, also diffuse or speckled calcifications.

2. Widening of elbow and knee joint space: subluxation or dislocation, osteoporosis, even extremity osteolysis, delayed bone development and skull ossification.

3. Other skeletal abnormalities: long ulnar styloid process, osseous union of ulna and radius, short proximal phalanx of the fifth finger, clubfoot, redundant teeth, kyphosis, and various chest abnormalities.

4. Cardiovascular angiography: can show aortic stenosis, aortic insufficiency, mitral insufficiency, spontaneous rupture of the main artery, dissecting aortic aneurysm, arteriovenous fistula and other congenital heart malformations.

Diagnosis

Diagnosis and differential diagnosis of Erler-Danlos syndrome
According to the three main symptoms of fragile skin and blood vessels, skin hyperextension, and excessive joint range of motion, the syndrome can be diagnosed. Combined with the abnormal findings of other organs or systems, the subtype can be specifically determined.

Differential diagnosis

1. Marfan syndrome mostly occurs at the same time with skeletal abnormalities such as slender limbs, spider fingers, etc., eye abnormalities can appear lens dislocation, glaucoma and high myopia, etc., cardiovascular system abnormalities can appear progressive expansion of the ascending aorta, Accompanied by aortic valve insufficiency, prominent pulmonary artery, etc. In addition, there may be a special face, that is, a rectangular head, a long and narrow face, and a high arched palate. Although there is joint relaxation and hyperextension, there is no symptom of fragile skin hyperextension.

2. Pseudoxanthoma elastica is distributed symmetrically in the skin folds, with small yellowish plaques or small nodular lesions in clusters or reticulates, as well as loose skin, insufficiency of blood vessels in the extremities, abnormal pulse, myocarditis and main symptoms. Cardiovascular abnormalities such as arteritis, characteristic changes of vascular-like pigmented patterns on the fundus, but no joint laxity.

3. Skin laxity This disease is mainly manifested as skin laxity, especially in the large folds, the loose skin is obviously draped or premature. Generally, there is no excessive joint movement. In this disease, when the skin is pinched by hand and then relaxed, its retraction force Very poor, it is difficult to distinguish this disease from Ehler-Danlos syndrome type IX, both have lysine oxidase deficiency, but the two genetic methods are different, the disease is more common in autosomal dominant inheritance.

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