What is Ataxia-Telangiectasia?

Capillary dilatation ataxia syndrome is a rare, complicated and poor prognosis neurocutaneous syndrome, also known as capillary dilatation ataxia syndrome, ataxia telangiectasia, ataxia Capillary vasodilation sign, Lovis-Bar sign. This disease is an autosomal recessive genetic disease, and the vast majority are sporadic cases. Clinical features include cerebellar ataxia that develops during infancy and early childhood, dilation of capillaries and conjunctival capillaries, recurrent paranasal sinus and lung infections, proneness to malignant tumors, and mixed immunodeficiency.

Basic Information

nickname

Ataxia telangiectasia, ataxia capillary telangiectasia

English name

ataxia telangiectasia syndrome

English alias

ATS, Louis-Bar syndrome

Visiting department

Neurology

Common causes

The pathogenesis is unclear, and the disease may be related to factors such as autoimmunity, abnormal tissue differentiation, DNA synthesis and repair defects

Common symptoms

1. Nervous system symptoms 2. Skin symptoms 3. Other manifestations such as respiratory infections, lung infections, etc.

Causes of telangiectasia ataxia syndrome

The pathogenesis of telangiectasia is unclear. Parents do not develop the disease. Peer disease occurs equally and there is an equal chance of men and women being involved. It is an autosomal recessive disease. The parents of most patients are married to non-close relatives and also have close relatives. Married. The disease may be related to factors such as autoimmunity, abnormal tissue differentiation, DNA synthesis and repair defects.

Clinical manifestations of telangiectasia ataxia syndrome

Neurological symptoms

The neurological symptoms of this disease are mainly cerebellar ataxia, which occurs in infancy and mainly affects the trunk and head. Children learn to walk with gait, their legs are very wide, followed by intentional tremor in the upper limbs. , Closed eyes and difficult to establish positive signs; children with delayed walking age, tendon reflexes weakened or disappeared, diaphragmatic reflexes are flexion, most children may be accompanied by dance-like movements or hand-foot asthma, can be masked by prominent cerebellar symptoms, Have nystagmus and cerebellar dysarthria, some children have pseudo-oculomotor nerve palsy, compensatory actions such as turning head to neck and blinking are often used to fix the target, physical and intellectual developmental retardation; after adolescence, most patients have spinal Impaired symptoms such as deep sensory disturbances and extensor diaphragmatic reflexes; muscular atrophy, weakness, and muscle twitching in the distal limbs can occur in adults.

2. Skin symptoms

Most children develop dilated capillaries at the age of 3 to 6 years old. Some children are already present at birth and may be late to puberty. The exposed part of the eyeball conjunctiva is similar to conjunctivitis and gradually disappears near the cornea. , Later appear in the eyelids, bridge of the nose, cheeks, external ears, neck, elbows and popliteal fossils, often exposed or irritated areas, the skin may have brown spots like pigmentation or loss of hair dull gray, because the facial subcutaneous Fat atrophy, reduced skin elasticity, and facial expressions with moderate scleroderma; in addition, chronic seborrheic blepharitis and seborrheic dermatitis are also common.

3. Other performance

Patients often have low humoral and cellular immune functions, especially the lack of secreted IgA, which is prone to recurrent respiratory infections, such as paranasal sinusitis, bronchitis and pneumonia, and otitis media. Repeated pulmonary infections can cause extensive fibrosis of the lungs, with clubbing fingers (toes) and pulmonary insufficiency. Most of the children had sexual dysfunction and did not have secondary sexual characteristics. Scoliosis can occur in the late stage of the disease due to limited mobility. Patients are prone to malignant tumors, mainly malignant lymphoma and lymphocytic leukemia. Loss of appetite may occur if liver function is affected.

Examination of telangiectasia ataxia syndrome

1. The percentage of lymphocytes in peripheral blood is reduced;

2. IgA, IgE deficiency or decrease;

3. Serum alpha-fetoprotein is higher than normal;

4. Cerebrospinal fluid examination is normal;

5. The EMG shows a decrease in the amplitude of the nerve evoked potentials, and the late manifestations are slower motor and sensory conduction speeds;

6. X-ray examination showed signs of chronic paranasal sinusitis, pneumonia, bronchiectasis or pulmonary fibrosis in some patients;

7. Cranial CT scan showed atrophy of the cerebellum and dilation of the fourth ventricle.

Diagnosis of telangiectasia ataxia syndrome

Diagnosis can be made based on typical clinical manifestations such as cerebellar ataxia, conjunctival capillary dilatation, recurrent severe respiratory infections, etc., which occur in infancy, and can be confirmed if laboratory and cellular and humoral immune function are low.

For atypical cases, such as no telangiectasias, no or only a history of mild respiratory infections, those with low serum immunoglobulins or low IgG but not low IgA but elevated, need to rely on detailed medical history, symptoms and signs, and laboratory Inspection and other data, and comprehensive analysis can make a diagnosis.

Differential diagnosis of telangiectasia ataxia syndrome

Early ataxia should be distinguished from acute infectious cerebellar ataxia, juvenile spinal hereditary ataxia, and hereditary polyradiculoneuritis; capillary dilatation should be distinguished from cerebral facial hemangioma syndrome and cerebellar retina Hemangiomatosis and other phases are identified; pigmented plaques should be distinguished from nodular sclerosis.

Complications of telangiectasia ataxia syndrome

Various symptoms and signs can appear. People with progressive cerebellar ataxia may be complicated by gaze nystagmus, strabismus, ocular movement difficulties, mask appearance, speech insufficiency, and mental retardation. Those with repeated respiratory infections are susceptible to B-cell lymphoma, Leukemia, breast cancer, and endocrine diseases often die from chronic infections and tumors.

Treatment of telangiectasia ataxia syndrome

Patients with respiratory infections are given effective antibiotics to control the infection. Immunoglobulin therapy can prevent infections and is beneficial to enhance the body's immune function. Drugs such as thymosin transfer factor can be used, with uncertain results. Levamisole can increase the lymphocyte conversion rate in patients with this disease. Bone marrow transplantation and thymus transplantation are still in the experimental stage. Diazepam (diazepam) can reduce involuntary movements, phenothiazines can relieve dance-like movements, and patients with intermediate and advanced stages can take vitamin E for treatment.

Prognosis of telangiectasia ataxia syndrome

Most patients with this disease often cannot walk independently due to ataxia and muscle atrophy around the age of 10. The main cause of death is pulmonary infection.

Prevention of telangiectasia ataxia syndrome

Genetic diseases are difficult to treat and genetic counseling should be performed. Preventive measures include avoiding marriages between close relatives, genetic testing of carriers, prenatal diagnosis and selective abortion, etc. to prevent the birth of children. Early diagnosis and treatment of sporadic patients can prolong survival.