Achondroplasia: What to know

Achondroplasia is an uncommon genetic condition that causes in low height and bent legs. It’s caused by a genetic mutation that’s more common in the offspring of older males.

Dwarfism is a condition in which a person’s development is limited owing to medical or genetic causes. Although dwarfism can be caused by a variety of factors, achondroplasia is responsible for around 90% of instances. Achondroplasia is a genetic ailment that can run in families, although most people who have it don’t have a parent who has it.

The genetics of achondroplasia, including the mutation that causes it, are discussed in this article. We also go through how heritable the condition is, who is most prone to have it, and what symptoms it causes.

Meaning

Achondroplasia
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Achondroplasia is a condition that inhibits bone development, according to a study from 2021. It can cause a variety of symptoms, including:

  • large head size
  • short digits
  • stiff elbows
  • short stature
  • bowed legs

These symptoms, according to the analysis, can have a major impact on people’s quality of life and capacity to accomplish everyday chores. Shorter height combined with tight elbows, for example, might make it harder to reach goods. Walking with bowed legs can be difficult and uncomfortable.

As a result of abnormal bone growth, people with achondroplasia can develop lumbar spinal stenosis. This condition causes the nerves in the spine to be compressed, resulting in pain, weakness, and mobility issues. It’s a serious complication that’s the leading cause of disability in achondroplasia people later in life.

Sleep apnea and hearing issues are two further achondroplasia consequences. The condition also reduces people’s life expectancy by about ten years compared to the general population.

The condition has no known treatment. Doctors, on the other hand, might prescribe a variety of therapy choices for achondroplasia symptoms and problems. These may include the following:

  • ear tubes for middle ear problems
  • guided bone growth
  • spinal fusions

These therapies can help people with achondroplasia minimize their symptoms and enhance their capacity to conduct daily duties.

Causes

A mutation in the FGFR3 gene leads to achondroplasia.

Genetic mutations are variations in genes that result in individual variances. Genes give instructions to cells in the body and control how they develop, interact, and perish. Any stage of this process can be influenced by genetic mutations, which can result in a wide range of features.

The fibroblast growth factor 3 (FGFR3) protein is encoded by the FGFR3 gene. This protein has an impact on cell division, maturation, and the formation of structures like bones. Overactive FGFR3 is caused by FGFR3 gene mutations, which might impact growth.

The FGFR3 gene mutation that causes achondroplasia causes a reduction in bone development in certain people.

Mutations in genes happen all the time and are typically innocuous. They may appear for no apparent cause. Prenatal exposure to pollutants, on the other hand, may increase the likelihood of FGFR3 gene alterations, according to some inconsistent data. As a result, this might be a risk factor for achondroplasia, however additional study is needed to prove the link.

is it hereditary?

Because parents transmit genes on to their children, achondroplasia can run in families. Someone who carries a FGFR3 gene mutation may pass it on to their kid, who may subsequently get the condition.

Achondroplasia, on the other hand, is uncommon, and according to a 2020 study, roughly 80% of people with the condition had parents of ordinary height. These parents’ chances of having another kid with the condition are extremely slim.

When one or both parents have achondroplasia, the situation becomes more complicated. If both parents have the condition, there is a chance that:

  • 25% chance that the child will have homozygous achondroplasia, which causes death during infancy
  • 50% chance that the child will have achondroplasia
  • 25% chance that the child will have average stature

Who does it affect?

A variety of other genetic variables can influence the likelihood of developing achondroplasia. Despite having parents who do not have achondroplasia, the age of the father can increase the probability of a person getting the FGFR3 gene mutation. Children born to fathers over the age of 34 are more likely to develop achondroplasia as they grow older if they carry the FGFR3 gene mutation.

According to research, around 1 in every 15,000 children will have the condition. However, skeletal dysplasia affects one out of every 1,875 children whose dads are beyond the age of 50 at the time of their birth. Skeletal dysplasia, which includes achondroplasia, is a collection of conditions that damage bone and cartilage cells.

It’s unknown if additional variables have a role in the development of achondroplasia.

According to a comprehensive evidence assessment published in 2020, achondroplasia is more frequent in specific parts of the world, such as North Africa, Sub-Saharan Africa, and the Middle East. The authors do note, however, that the quality of data from these areas is weak, and that additional research is required.

Conclusion

Achondroplasia is a bone-growth condition caused by a rare genetic mutation. It causes a number of issues that have an impact on everyday life, such as difficulties walking and reaching.

Achondroplasia people can pass on the genetic mutation that causes the condition to their offspring. Many offspring of people who have the condition, on the other hand, will not develop it.

If the father is above 35 years old at the time of the kid’s birth, the chances of the child developing achondroplasia rise.

Sources:

  • https://pubmed.ncbi.nlm.nih.gov/31294928/
  • https://www.cancer.gov/publications/dictionaries/cancer-terms/def/fgfr3-gene
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7540685/
  • https://www.medicalnewstoday.com/articles/achondroplasia
  • https://www.ncbi.nlm.nih.gov/books/NBK1152/
  • https://www.ncbi.nlm.nih.gov/books/NBK559263/

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