Fragile X Syndrome

Fragile X syndrome is also called as Martin–Bell syndrome, or Escalante's syndrome is a genetic syndrome. Nearly half of all children with fragile X syndrome meet the criteria for a diagnosis of autism. It is an inherited cause of intellectual disability especially among boys.

Aside from intellectual disability, prominent characteristics of the syndrome may include an elongated face, large or protruding ears, flat feet, larger testes and low muscle tone. Recurrent otitis media and sinusitis is common during early childhood. Speech may be cluttered or nervous. Behavioral characteristics may include stereotypic movements (e.g., hand-flapping) and atypical social development, particularly shyness, limited eye contact, memory problems, and difficulty with face encoding. Some individuals with fragile X syndrome also meet the diagnostic criteria for autism

Fragile X syndrome is a genetic disorder which occurs as a result of a mutation of the fragile X mental retardation 1 (FMR1)gene on the X chromosome, most commonly an increase in the number of CGG tri nucleotide repeats in the 5' un translated region of FMR1. Mutation at that site is found in 1 out of about every 2000 males and 1 out of about every 259 females. Occurrence of the disorder itself is about 1 in every 3600 males and 1 in 4000–6000 females. Although this accounts for over 98% of cases, FXS can also occur as a result of point mutations affecting FMR1. Due to the fact that there are no current treatments or cures for the underlying defects of FXS, it is even more critical for medical science to innovate new and efficacious pharmacological treatments as well as targeted behavioral interventions.

A Sweden screening study in 2003 estimated an overall prevalence of FXS in the general population of 2.3/10,000 (or 1 in 4,425). Other estimates suggest it is present in 1 in 4,000 males and 1 in 8,000 females but that this may be an underestimation. Prevalence depends on the population studied.The premutation is far more common. Two to four times as many females as males carry the gene abnormality. This has an estimated prevalence of 1 in 130-260 females and 1 in 250-810 males