A rare disease is defined as a disease that affects fewer than 1 in 2.000 people. However, despite of X Fragile Syndrome (FXS) being a rare disease, it is the first cause of inherited intellectual disability. For this reason, we want to focus on this pathology.
Fragile X Syndrome is a genetic disorder caused by the transcriptional silencing of the FMR1 gene (Xq27.3) due to the progressive expansion and subsequent methylation of (CGG)n trinucleotide repeats in the 5′-untranslated region of the gene. FMR1 codes for the fragile X mental retardation protein (FMRP), a protein needed for normal brain development.
FXS is an X-linked dominant disorder, which affects both males and females. However, females often have milder symptoms than males. The clinical phenotype is variable, with mild to severe intellectual deficit that may be associated with behavioural disorders and characteristic physical features (high forehead, prominent and large ears, hyperextensible finger joints… between others).
FXS can be diagnosed by testing a person’s DNA from a blood test. For example, the Adellgene® Fragile X Screening allows the molecular diagnosis of the disease. Although 80% of people with X Fragile Syndrome are not diagnosed, diagnosis of FXS can be helpful to the family because it can provide a reason for a child’s intellectual disabilities and behaviour problems. This makes it possible that the family and other caregivers to learn more about the disorder and manage care so that the child can reach his or her full potential.
Currently, there is no cure for FXS. Nevertheless, therapy to learn to talk, walk, and interact with others, can help people learn these important skills. Besides, medicine can be used to help control issues, such as behaviour problems. To develop the best treatment plan, people with FXS, parents, and health care providers should work closely with one another, and with everyone involved in treatment and support, which may include teachers, childcare providers, coaches, therapists, and other family members.
Finally, the FXS is only one of many existing rare diseases, and we must continue trying to make these patients’ life easier.