Axondroplazija – Dwarfism

Description dwarfism

Axondroplazija – It is a genetic disease, that causes dwarfism (slight increase). With this disease, bone and cartilage grow properly. This is the most common cause of dwarfism.

If you have a patient achondroplasia growth does not exceed 130 cm. Most growth retardation occurs in the humerus (the bone between the shoulder and elbow) and femur (the bone between the hip and the knee). It may also meet facial hypoplasia.

Achondroplasia is the most common form of inherited disproportionate short stature. It is found in one case, 26000 – 40000 Births.

Reasons for achondroplasia

Achondroplasia is a genetic disorder. It is caused by mutations in the FGFR3, and stored in the fourth chromosome. At the same time it inhibits the growth of cartilage. FGFR3 encodes protein, called fibroblast growth factor 3. This protein is responsible for the bone growth of the organism. FGFR3 in achondroplasia can not act properly, and bone growth, cartilage slows. This leads to shorter bones, abnormal shape of bones, and low growth.

Gene achondroplasia can be passed from one generation to another. If a parent has the disorder, It exists 50% the likelihood of gene transfer achondroplasia to offspring. In most cases (80% -90%) Achondroplasia is the result of a spontaneous mutation (sudden genetic defect), It occurs in developing embryos.

Risk Factors dwarfism

Factors, which increase the likelihood of achondroplasia:

I have achondroplasia from a parent;

• Children, in which the mutated FGFR3 gene;
• Adult father's age can also cause spontaneous mutations.

The symptoms of achondroplasia

The symptoms of achondroplasia may take the form of:

• A small increase, shortened limbs, which are noticeable at birth;
• Adults usually reach a height 1-1,3 m;
• A large head and prominent forehead;
• Parts of the face can be underdeveloped;
• At birth, the legs appear straight, but, when the child begins to walk, develops deformity of the knee or bending the legs;
• Arms and legs are normal, but their fingers are short;
• Bending the arm at the elbow may be restricted, but usually restricts patients with achondroplasia from doing any act;
• Children can develop curvature of the lower back and toddle walking;
• Dental problems.

Other symptoms include:

• Weight problems;
• Crooked legs;
• Inflammation of the middle ear, especially in children. If you do not take appropriate measures, this may lead to hearing loss;
• Dental problems;
• Gidrocefaliя (water on the brain);
• Neurological diseases and diseases of the respiratory tract;
• Fatigue, pain and numbness in:
• Lower Back;
• Problems with the spine.

Patients, which have two copies of the mutated gene (eg, one from each parent, also known as homozygous) generally die a few weeks or months after birth. They, who have only one copy (eg, from only one parent, heterozygous) have a normal life expectancy and intelligence, although the development of motor skills in children often takes longer and there is an increased risk of death during the first year of life due to problems with the respiratory system. In adulthood, they, usually, independent in their daily activities and life.

Diagnosis of achondroplasia

Diagnosis includes:

• Clinical evaluation;
• Radiographs.

It can be used molecular genetic testing, to detect mutations in the FGFR3 gene. Such testing 99% probability reveals problems and available in modern clinical laboratories. A doctor can diagnose disorders in the newborn during the observation of physical symptoms. To make sure, that dwarfism is caused by achondroplasia, X-rays may be needed.

It is important to ensure, that the patient does not develop spinal stenosis . The doctor evaluates the degree of bladder control. Weakness and loss of bladder control – symptoms of spinal stenosis.

Treatment

Unfortunately, there are currently no methods, that can cure achondroplasia. As it is now known, that achondroplasia is caused by the absence of growth factor receptor FGFR3, scientists are exploring ways to create additional growth factors, which can bypass the missing receptor and lead to normal bone growth. This method of treatment may, will appear in the future.

Medication

Treatment of human growth hormone has been used for over a decade and slightly increases the rate of bone growth, at least the first year of life. Several studies, in which children, receiving treatment with growth hormone reached more (or normal) growth.

Surgery

Surgery is sometimes necessary, to correct certain skeletal deformation.

The merger of the vertebrae – operation, allowing to connect the individual vertebrae. Surgery is indicated in patients with significant spinal kyphosis.
Laminectomy – dissection of the spinal canal surgery, to relieve pressure pressure on the spinal cord from spinal stenosis. Spinal stenosis, narrowing of the spinal canal, It is the most serious complication of achondroplasia.
Osteotomy – leg bones are cut and fastened in the correct anatomical position. The procedure is indicated for patients with severe deformation of the knee or curved legs.

While primarily used osteotomy, to correct the deformation, In recent years, the procedures for lengthening bones for children with short stature, including patients with achondroplasia. The procedures are lengthy and traumatic. Common complications, sometimes very serious. In combination with growth hormone, these procedures can somewhat increase growth.