What is Fragile X?
Fragile X syndrome (FSX) is the most frequent inherited form of intellectual disability. The disorder is caused by an expansion of a trinucleotide segment (CGG) in the Fragile X Mental Retardation-1 gene (FMR1) located in the X chromosome. This leads to a very low or loss of production of the FMRP protein. The severity of the disease is dependent on the number of repeats of the trinucleotide segment. Healthy individuals range from 5 to 44 repeats, there is a borderline zone between 45-54 repeats (carriers do not show fragile X phenotype, but present ataxia, and/or anxiety among others), and a partial mutation (PM) where individuals range between 55 and 200 repeats. Finally, having more than 200 CGG repeats leads to Fragile X. The expansion of the number of repeats happens during the maternal transmission of the X chromosome (rarely of the paternal).
Signs and symptoms
Signs that a child might have FXS include developmental delays not sitting, walking, or talking at the same time as other children the same age); learning disabilities (trouble learning new skills); and social and behavior problems (such as not making eye contact, anxiety, trouble paying attention, hand flapping, acting and speaking without thinking, and being very active).
Children with Fragile X
It estimated to have a worldwide prevalence between 1:5,000-7,000 men and 1:4,000-6,000 women from different ethnic groups.
Diagnosis of Fragile X
FXS can be diagnosed by testing a person’s DNA from a blood test. There is no cure for FXS. However, treatment services can help people learn important skills. Services can include therapy to learn to talk, walk, and interact with others. In addition, medicine can be used to help control some issues, such as behavior 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.
Sources and useful links:
Centers for Disease Control and Prevention (CDC)