Introduction
Ma Fang syndromeThere are also congenital mesoderm dysplasia, Marchesani syndrome, spider indications, and limb slenderness. It is characterized by peripheral connective tissue malnutrition, skeletal abnormalities, internal eye diseases and cardiovascular abnormalities, and is a hereditary disease characterized by connective tissue as a basic defect.
Cause
(1) Causes of the disease
The disease is autosomal dominant, and Dietz et al. (1991) mapped the disease gene to 15q15~q21.3 through linkage analysis of the family. In many tissues of the human body such as endocardium, heart valve, large blood vessels, bones, etc., there are accumulation of mucopolysaccharide such as chondroitin sulfate A or C, which affects the structure and function of elastic fibers and other connective tissue fibers, so that corresponding Organ dysplasia and dysfunction. Abraham et al (1982) suggested that aortic elastin is abnormal, desmosome and isopsin protein are reduced, and lysyl residues are correspondingly increased, which is the main change of the disease. The urinary hydroxyproline excretion increased, and the blood mucin and mucopolysaccharide also increased.
(two) pathogenesis
Through the family's linkage gene mapping dominant inheritance, it can be proved from the increase of urinary hydroxyproline excretion in patients, this disease is elastic fiber defect, that is, abnormal collagen metabolism. Connective tissue fibers are important components in the body's tissue structure, so when it is abnormal, it affects the whole body's organs (mesoderm tissue), especially the bones and cardiovascular system. The spider's fingers and the depressed chest or the stern chest indicate an excessive increase in the longitudinal axis of the tubular bones, fingers and ribs of the extremities, possibly due to defects in the periosteal fiber composition. There is acidic mucopolysaccharide deposition in the middle layer of the aorta and pulmonary artery. The disease has a family tendency and is autosomal dominant.
Pathology: gross eye changes, ascending aorta dilatation, chronic aortic dissection, heart valve showed mucinous edema, valve balloon, chord thickening, cardiac hypertrophy and mitral calcification and dermatoglyph Abnormal, etc. The pathological changes of this syndrome are most prominent and representative of the cardiovascular system. Microscopically, the aortic middle layer elastic tissue is sparse and fragmented, with smooth muscle changes in an irregular thread shape, the amount of collagen increases, and it is seen that the metachromatic substance is scattered in the middle layer. Aortic dissection tumors showed cytoplasmic necrosis and moderate degeneration of the elastic fibers, accompanied by smooth muscle bundle disorders. The histopathological changes of the aortic valve are normal structural destruction and loss, cystic degeneration and loss of tissue fibroblasts. Pathological changes in the skin manifested as vacuolar degeneration and dislocation of elastic fibers. Synovial changes in the joints are also elastic fiber degeneration, collagen increase and metachromatic sacs.
symptom
1. Skeletal lesions are the main lesions, and are easy to prompt diagnosis, the incidence rate is 80% to 97.2%.
(1) The body is thin and tall, and the limbs are slender, especially the forearms and thighs: 1 height >180cm; 2 finger distance> height (both hands stretch, two middle finger distance - height >7.6cm, diagnostic value); 3 lower body ( From the pubic symphysis to the sole of the foot > upper body (from the top of the head to the pubic symphysis), the ratio is > 0.92 (normal person ≤ 0.92).
(2) Spider finger/toe-like changes: 1 finger (toe) is particularly long, with a typical spider-like change, hand to height ratio >11%, foot to height ratio >15%; 2 thumb sign: The thumb is adducted, the other 4 fingers are fists, the tip of the thumb is beyond the lower edge of the palm, and about half of the patients have this sign; 3 wrist sign: holding the hand under the styloid process of the other hand with one hand The thumb and the little finger can be contacted under no-pressure conditions, with 82% of the sign; 4 metacarpal index and phalanx index are increased, the normal metacarpal index is <8, and the metacarpal index of the patient is >8.4 ( 8.4 to 10.5). 5 Other finger (toe) anomalies: There may be a clubbing, a finger (toe), a thin palm, and a flat foot.
(3) Skull lesions: 1 long, narrow, convex; 2 skull index > 75.9; 3 eyes are too wide or too narrow, mandibular length; 4 teeth are not aligned, lack of wisdom teeth, etc.; 5 ears forward Or drooping, the ear wheel is meager, shaped like an old man.
(4) changes in thoracic and spinal deformities: 1 chicken breast, flat chest, funnel chest; 2 hunchback, spine or spine.
2. The incidence of ocular lesions is between 63.8% and 68.3%.
(1) Dislocation or subluxation of bilateral lens, the incidence of which accounted for 83% to 86.8% of ocular lesions, and all patients with high dislocation.
(2) Retinal detachment, iris tremor, cataract (occurring in the late stage of the disease), strabismus, pupil dilation, secondaryglaucomaWait.
3. Cardiovascular disease is one of the main clinical features of this disease. It can be as early as 5 years old and as late as 60 years old, and it is progressive. The clinical incidence rate was 38.5%-60%; the incidence of pathological examination was 95%-100%, and the main lesions were aortic necrosis and cystic dilatation.
(1) Aortic lesions: according to the incidence of aortic root expansion with aortic valve insufficiency, ascending aortic aneurysm, aortic dissection and so on. Bowers believes that ascending aortic dilatation with or without aortic regurgitation is one of the features of the diagnosis of equine syndrome; and those with aortic regurgitation, mostly male, with diastolic murmur and rheumatic sex The location of the valvular insufficiency is different, mostly located in the 2nd to 4th ribs on the right edge of the sternum. In recent years, some scholars have pointed out that the separation of dissection in pregnant women is mostly Ma Fang syndrome.
(2) mitral valve prolapse: due to mitral valve mucoid degeneration, the leaflets become thin, too long or the chordae tendon elongation caused by mitral valve prolapse. Severe cases complicated by mitral insufficiency.
(3) Coronary artery involvement: causing angina or myocardial infarction.
(4) Other congenital cardiovascular malformations: such as atrial septal defect, ventricular septal defect, patent ductus arteriosus, pulmonary umbilical stenosis and dilatation.
(5) Heart enlargement, arrhythmia, etc.
Cardiovascular disease is the main cause of death in Ma Fang syndrome, accounting for 70% to 90% of the cause of death.
4. Central nervous system lesions
(1) Dural bulging: It is one of the characteristics of this disease. It is more common in lumbosacral dural bulging. Its characteristics are: 1 high incidence rate (63%~66.7%); 2 and other three signs (skeletal malformation, lens dislocation, aortic lesions) has no relationship with severity; more than 3 asymptomatic; 4 can be found by X-ray photograph, CT/MRI examination; 5 can also be combined with meningioma, extracellular matrix Caused by defects.
(2) Subarachnoid cysts.
(3) pelvic meningocele.
5. Other parts
(1) Subcutaneous fat is rare and muscle development is poor.
(2) joint relaxation, expansive shrinkage lines or wrinkles.
(3) Inguinal hernia, umbilical hernia, and transverse hernia.
1. The diagnosis of this syndrome is based on
(1) Special bone changes, that is, the tubular bone is slender, especially with the finger and the metacarpal bone. The cortical bone is thin and slender and changes like a spider.
(2) Congenital cardiovascular abnormalities.
(3) Eye symptoms.
(4) Family history.
Three of the above four clinical criteria can be diagnosed, and only two of the first three changes can be diagnosed as incomplete equine syndrome.
2. Mckusick (1995) lists cardiovascular abnormalities in horse syndrome as
(1) aortic dilatation (ascending aorta, descending aorta), aortic dissection, aortic stenosis, patent ductus arteriosus.
(2) Pulmonary artery abnormalities (pulmonary artery dilatation, pulmonary aneurysm).
(3) septal defect (atrial septal defect, ventricular septal defect).
(4) abnormal valve and accompanied by subacute bacterial endocarditis.
diagnosis
The disease must be differentiated from the following diseases: 1 homocystonia; 2 rheumatic aortic regurgitation; 3 familial mitral valve prolapse or aortic valve prolapse; 4 familial aortic annulus dilatation; 5 congenital contracture spider-like finger (toe) and other identification.
complication
1. Cardiovascular is most likely complicated by aortic idiopathic dilatation, aortic stenosis, aortic dissection and mitral anomalies.
2. Ocular lesions can be complicated by dislocation or subluxation, high myopia, glaucoma, retinal detachment, iritis and so on.
3. Nervous system lesions can be complicated by subarachnoid hemorrhage and internal carotid aneurysm, epileptic seizures. In addition, patients with Ma Fang syndrome can also have spina bifida, spinal cord bulging, syringomyelia.
treatment
(a) treatment
1. The principle of treatment for prevention and treatment of cardiovascular complications, medical support for symptomatic treatment, surgical treatment when conditions are available.
2. Treatment measures There is currently no specific treatment.
(1) general treatment: 1 to avoid strenuous exercise; 2 to prevent infection; 3 to make up a lot of vitamin C, which is beneficial for the formation of collagen by hydroxylation of proline and lysine.
(2) Complications of internal medicine prevention and treatment: 1 assimilating androgen to promote protein synthesis and prevent connective tissue damage. Oral dehydrogenationMethyl testosterone(methandrostenolone) 5mg, 1 time / d, long-term use. 2 patients with no heart failure can use beta blockers to reduce ascending aortic pressure, prevent QT interval prolongation and ventricular arrhythmia. oralPropranolol(propranolol) 10 mg / time, 3 times / d; oral metoprolol (betaloc) 12.5 ~ 50mg / time, 2 ~ 3 times / d. 3 Active prevention and treatment of heart failure and arrhythmia. 4 prevention and treatment of eye lesions.
(3) Surgical treatment: surgical indications: 1 severe aortic insufficiency or mitral insufficiency, 2 aortic dissection or arterial dissection, 3 combined with other congenital malformations, 4 eye lesions, etc. , as appropriate, correct or seek early surgery.
(two) prognosis
The natural course of the Ma Fang syndrome, although the individual speed of the lesions varies greatly, but the overall prognosis is sinister. According to a survey by Mardoch et al, one in three patients with horse syndrome died before the age of 32, and 2/3 died at the age of 50. In 1995, Sileveman reported that the average age of Ma Fang syndrome was only 40 years old. The main cause of death is mostly caused by cardiovascular disease. The most common are aortic aneurysm rupture, pericardial tamponade or aortic regurgitation and heart failure due to mitral valve prolapse or myocardial ischemia, severe arrhythmias.
prevention
1. Ma Fang syndrome drug treatment, the main purpose is to slow or delay the occurrence of cardiovascular disease, prevention and treatment of ventricular arrhythmia.
2. Regular follow-up review, life-long application of beta blockers.
3. Limiting the amount of physical activity can slow down and delay the onset and development of cardiovascular disease.
简体中文