Description achondroplasia
Achondroplasia is a common cause of dwarfism. It occurs as a sporadic mutation in approximately 80% of cases (associated with advanced paternal age) or it may be inherited as an autosomal dominantgenetic disorder.
Achondroplasia meaning of the word comes from Greek. It means underdevelopment cartilage. But not say anything about the nature of the disease. Name chondrodystrofie is practically the same, but is no longer used. Achondroplasia is the most common cause of disproportionate dwarfism. In adult patients achieve an increase in diameter of 125 centimeters.
Achondroplasia is an autosomal dominant inherited disease. This means that the affected parent have a 50% probability that they will be born equally affected child. However, most mutations (errors in DNA) a so called. De novo. Thus, the healthy parents with the birth of a handicapped child. Mutations occur exclusively in the paternal germ line, the frequency increases with the age of the fathers (> 35 years).
In 99% of mutations located in the gene for receptor ligamentous growth factor (FGFR 3 gene).Occurrence achondroplasia is measured in the range of 1:15 000 to 1:40 000 live-born infants. It affects both sexes and all ethnic groups. Three to five percent of patients die within the first year of life due to some of the complications listed in the following text.
Risk factors achondroplasia
A risk factor is increasing age the child’s father. Generally at such risk age group considered to men over 35 years. Other risk factors are obviously sick parents, who have a 50% risk for the birth of a sick child. When the mutation arose de novo risk is only slightly higher than the risk in the population, ie 1:15 40000 births.
prevention of achondroplasia
Prevention of healthy parents is not possible. Men should not nechávavat giving birth to “old age”.Affected parents then ask them how much they want children. With a 50% probability that the child will be sick. However, some patients with achondroplasia achondroplasia perceive as a disease, there are entire families affected by the disease. Patients pairs can be done prenatal examination mutation of the FGFR 3 gene. Ultrasound can detect achondroplasia from the 24th week of pregnancy. Previously it can about with the help of ultrasound speculate when measuring the length of the femur, which is usually reduced.
The symptoms of achondroplasia
As already mentioned, achondroplasia is called representative. Of disproportionate dwarfism.Children are born with shortened proximal (closer to the body) parts of the limbs and relatively long, narrow thorax. Characterized by a large head with protruding forehead. Birth length is only slightly less so at first glance it is not too noticeable newborn. With age, growth retardation highlights.Patients usually have normal intelligence. Delayed motor development is the rule. It is caused by reduced muscle tension, problems with balancing big heads, sometimes added yet narrowing of the spinal canal. Skull bones grow abnormally. This results in a smaller face portion. The teeth are crowded. Infants (children under one year of age) have lower muscular tension. Even that is transverse later posazování and first steps. Over time, the muscle tension normalized. If not, the child should be examined by a specialist. It may be a spinal cord compression. Some joints are limited moving, while others excessively. Patients have problems with my spine, before they occur arthritis joints.
treatment of achondroplasia
Treatment of such diseases as yet unknown. But what can affect the complications of the disease.In childhood, it is necessary to take care of the airway and treat their infection. Care must be taken to correct motor development, they are generally useful rehabilitation exercises. Surgically may affect a little too small. They do a prolongation (renewal) limbs. Performance, however, is a lengthy process, several stages and not entirely painless. The benefits of growth hormone therapy is not completely clear. It is not clear correlate between the total cost of treatment and the fact that baby grows a few centimeters. The effect is also very individual. It is very important psychosocial assistance. There are companies in patients with achondroplasia (eg. Tom Thumb), that are willing to patients and their families to advise and assist in difficult situations and play an important role in the integration of such children and later adults in the group.
complications of achondroplasia
Infants are generally delayed. Parents would be with them, however, they should be patient and when posazování or walking is to not force anything. Often anxious parent will cause more mischief than good. The infant then, for example, may appear so. Gibbus (shoulder) in the lumbar spine.Usually it is only transitional and does not need special care. Lower muscular tension that accompanies mainly infants should normalize over time and the baby should classmates in motor development to catch up. If not, it is better to visit a specialist. It is possible that problems with movement is caused by a narrowing of the spinal canal. Infants may appear more frequent breaks in breathing (apnea). The cause can be narrowed spinal cord compression in output from the brain to the base of the skull, where the breathing center. Nasopharynx is due to a reduction midface also narrowed to do can still add reduced lung volume narrowing the infant’s chest.
School children suffer similar reasons as infant apnea frequent respiratory infections and middle ear. Repeated middle ear infections lead to the accumulation of fluid or pus in the ear. This can result in hearing loss the child and consequently poor speech development. Adults with achondroplasia tend to put on weight. Together with the already deformed joints this leads to various orthopedic disorders. Frequent are curved leg in O called. Varus. Cervical and lumbar spine are very stressed. All this leads to frequent complaints of how back pain, difficulty walking. When narrowed spinal canal, leads to the oppression of radicular when exiting the spinal cord. There are sensory disturbances such as various itching, pain, burning and the like. In individuals with achondroplasia must think of the difficulties in intubation, which is caused by narrowed the nasopharynx. Not recommended for epidural anesthesia.
Other names: Chondrodystrofie