Fragile X Syndrome is a genetic disorder that is acquired by children from genetic defects passed on by parents, which presents with hampered growth, development and brain functions. This rare inherited ailment is also known as Martin-Bell Syndrome and is more often seen in young boys than girls. Fragile X syndrome is a chronic illness that triggers major complications and the affected individual usually requires constant support from a caregiver, apart from lifelong medical treatment.

Also Read: Alagille Syndrome: How This Genetic Disorder Negatively Influences The Liver And Heart In Children
Fragile X Syndrome

Causes Of Fragile X Syndrome:

Fragile X syndrome is caused by chromosomal defects in the FMR1 gene. This gene is located on the X chromosome, which along with the Y chromosome are the two sex chromosomes in the human system. While men have one X chromosome and one Y chromosome, women have two X chromosomes within the system.

The faulty or mutated FMR1 gene results in either the lack of synthesis or impaired production of a protein called fragile X mental retardation protein 1. The chief role of this protein is to regulate the coordination and development operations of the nervous system. Since this function is hampered, fragile X syndrome prompts various developmental delays and stunted growth in affected children.


Fragile X syndrome gives rise to a spectrum of symptoms owing to the restricted advancement of nervous system functions. These comprise:

  • Constrained and delayed development of mobility, control and coordination activities in the system, such as learning how to sit, stand, walk in babies and toddlers
  • Delayed development of speech abilities, with stuttering
  • Hampered brain functions, with difficulty learning and grasping new concepts
  • Autism
  • Obstructed development of social and behavioural skills
  • Attention deficit hyperactivity disorder
  • Mood swings, with depression and anxiety
  • Problems with sleeping continuously at night
  • The occasional onset of seizures
  • Distorted facial features, like a large forehead, very elongated face
  • Abnormally protruding ears, forehead and chin
  • Loosely hanging joints, with unstable connective tissue structures, like in spinal muscular atrophy
  • Flat feet

Also Read: Spinal Muscular Atrophy: Causes, Symptoms Of This Genetic Disorder With World's Most Expensive Drug


The diagnosis of fragile X syndrome is generally confirmed between the ages of 3 and 4 in young boys and girls. In many cases, girls tend to display only odd facial or bodily features with minimal or no nervous system impairment, while boys exhibit more serious complications of limited thinking, behavioural and intellectual skills.

The doctor carefully studies the external appearance of the child and records any irregular facial aspects of the ears, forehead, face and chin after a thorough physical examination. The child’s parents are also enquired whether they already suffer from fragile X syndrome and the physician also asks if any close family members have the genetic disorder.

The instance of fragile X syndrome, abbreviated as FXS, is verified once the medical expert carries out a DNA blood test known as the FMR1 DNA test. This assay helps to identify any mutations present in the FMR1 gene and conclude the reason for the health anomaly in children.


There is no cure for fragile X syndrome. It is a chronic condition that begins in early childhood due to inherited genetic defects from parents and the affected child requires lifelong medical care and support.

To help children with fragile X syndrome learn to walk, talk and cultivate social skills, specialised and trained teachers, therapists and healthcare providers work together in building these basic abilities. Furthermore, the parents of the affected child are also coached on how to handle the daily needs and medical care requirements of those with fragile X syndrome.

In this manner, the overall quality of life of the child affected by fragile X syndrome can be enhanced and they can go on to complete their schooling and college education and seek basic jobs. However, since the mental capabilities are damaged more in boys than girls in fragile X syndrome, medical experts have reported a better outcome of treatment in women than in men. The majority of affected boys suffer from restricted brain functions and stunted mental growth owing to hampered nervous system development.

Additionally, to cope with symptoms of depression, anxiety, the doctor prescribes antidepressants and anxiolytic medications to uplift moods, improve mental functions, productivity and overall wellbeing.