Genetic diseases: Fragile X Syndrome

Definition

In our post today about genetic diseases We'll talk about Fragile X Syndrome. This term is used to describe a genetic disorder that is currently the most common form of inherited intellectual disability. It's also the second most common genetic cause that primarily affects men and is transmitted by women.

Causes

Fragile X Syndrome appears due to mutations in the gene FMR1 X-linked. This gene contains the instructions for making a protein called FMRP, which is important for normal brain development. The fact that the X chromosome is affected by the mutation is the main reason why the disorder is seen more often and with greater severity in men, who only have one copy of that chromosome. In women, who have two copies of the X chromosome, the effects are less severe, and symptoms may not even appear (although they can pass it on to their children).

Genetics of the disease

The gene FMR1 It is responsible for producing a protein, FMRP, which prevents intellectual disability and also influences the formation of connective tissue (joints, etc.). When the gene mutates, it is inactivated, decreases, or completely ceases production of the FMRP protein. Therefore, depending on the amount of protein produced, the affected person suffers from a series of abnormalities, including intellectual disability, to a greater or lesser extent.

Symptoms

The most common symptoms are those associated with cognition and behavior, usually with delayed speech or language development before the age of two. Most affected individuals have mild to moderate intellectual disabilities. However, they may present with other symptoms such as a broad forehead, macrocephaly, prominent ears, and even metabolic problems.

Diagnosis

Many of the symptoms of fragile X syndrome are similar to other diseases, although the severity of the symptoms can vary greatly from one person to another, so if fragile X syndrome is suspected, a genetic test should be done to identify changes in the FMR1 gene , This test is a blood test using specific molecular biology techniques . In www.genotica.com We have tests that study this disease, such as the test SXF expansion study , by Lorgen.

Treatment

There is currently no cure for FXS, but some symptoms can be treated with educational, behavioral, or physical therapy and medication . Along with Down syndrome, FXS is one of the most common genetic causes of mental retardation.