Fragile X Syndrome is the most commonly inherited cause of intellectual diability. The FMR1 gene on the X chromosome is responsible for the deficiency of the FMRP (Fragile Mental Retardation Protein). Symptoms can include: learning difficulties, autism, severe anxiety, seizures in 20-25% of boys, attention deficit, and hyperactivity. FX affects 1 in 4,000 boys and 1 in 6,000 girls. FX is carried by 1 in 260 women and 1 in 800 men. A woman who carries the gene that causes an X-linked condition has a 50/50 chance of passing it to a child, whether it is a son or daughter. This is because she has two X chromosomes, and she passes one or the other for a son or daughter. A man with the same X-linked gene passes it to all of his daughters and none to his sons. This is because he passes his only X chromosome to his dauthers and his Y chromosome to his sons.
Nicolas, who is 3 years old had genetic testing which led to the discovery of our Fragile X diagnosis just after birth. Monica had a repeat (or genetic stutter, 140) on one X chromosome. This caused the full mutation to be passed on to Nicolas. Santiago, who is 6 year old, is not affected, which means he got the other X chromosome. We have learned so much since our diagnosis! For instance, the number of genetic repeats does not correspond to the intellectual ability of the person with FX. The range of ability varies from mildly affected to severe. Early intervention is crutial! We have come a long way! While developmental delays may cause Nicolas to adapt to learning on a different level, we are proud of the fact that he is continuing to learn daily! Behavior and potty training remain difficult. The inability to express himself seems to be the determining cause of acting out at times. He also gets overstimulated which makes going places very challenging.
We thank you in advance for your contribution. Research and early intervention really play a role in whether Nicolas and other children with Fragile X can live independent lives.