All you wanted to know about Fragile X Syndrome

Fragile X syndrome is an inherited condition that causes intellectual disability.

What is Fragile X Syndrome?

Fragile X syndrome or (FXS) is a genetic condition which is the most common inherited cause of Autism and intellectual disability. It occurs across all races and castes and affects males more severely than females. It is also called Martin-Bell syndrome or Escalante syndrome.

Symptoms of Fragile X Syndrome

There are certain signs and symptoms that are typical in those afflicted with Fragile X syndrome:

1. Physical characteristics – These include a long face, large ears, high arched palate, highly flexible joints (especially fingers), low muscle tone and enlarged testes at puberty (macro-orchidism).

2. Medical conditions – Serious health conditions that occur as a consequence of Fragile X syndrome are hernia, , visual defects , seizures , recurrent ear infections and a heart murmur (abnormal sound heard by a physician using a stethoscope) due to weak connective tissues in multiple organ systems in the body . In adult life some men develop hand tremors and difficulty in walking due to lack of balance. Some women may develop premature ovarian failure or POF in which their ovaries stop functioning before 40 years of age. This means getting pregnant may be a challenge unless the problem is treated. Early menopause leads to its share of problems like dry skin and osteoporosis due to lack of oestrogen secreted by the ovaries.

3. Speech and language – This may range from one end of the spectrum to another but men are more severely affected than women. Women are able to read and write without difficulty and can also follow instructions. Men however have trouble with pronunciation, reading and understanding simple instructions and giving meaningful responses in a discussion. They also have difficulty in altering pitch, tone and loudness; some may stutter and others may repeatedly ask the same question. In the case of children, they may talk much later than their peers and some may not ever be able to talk.

4. Intelligence – Most people suffering from FXS have IQs ranging from mild to moderate. They have an inability to think, reason and learn due to limited intellectual capacity. They may have anxiety, attention disorders and learning problems whereas they are generally good at remembering pictures and visual patterns. Females have almost normal cognitive development , thus showing that both sexes have different strengths and weaknesses making a thorough evaluation an absolute necessity. Problem areas include organising information, solving problems and thinking about abstract ideas. Children with FXS are categorized as special children and can often do well academically with special coaching. Adults can usually hold down simple jobs.

5. Sensory – Our five senses are that of sight, smell, taste, touch and hearing. People with FXS have sensory overload to even minor sounds for example, a dog barking is enough

to upset them. They do not like to change their locations. They are very sensitive to textures of clothes they are wearing. They shy away from even a light touch.

Fragile X Syndrome Causes

Fragile X syndrome is a genetic disorder and can get be inherited from either parent. Fragile x syndrome inheritance details include:

1. It is a known genetic mutation disorder on the FMR1 gene on the X chromosome. It is a form of X-linked dominant trait. The affected X chromosome can be inherited from any parent. Men will only give it to their daughters while a woman may give it to a child of either sex. In the latter scenario, the male child is severely affected while in the female child, the symptoms may range from mild to severe.

2. The transmission of the aberrant X chromosome increases with each passing generation.

3. The affected gene, named FMR1 does not produce the correct protein. This results in several abnormalities; mental disability is the most important feature of FXS.

Fragile X Syndrome Diagnosis

A series of tests can determine whether or not a person has Fragile X syndrome. If detected, various management options are available.

Fragile X syndrome has many characteristics similar to autism and attention deficit hyperactivity disorder or ADHD. In fact, when a diagnosis of autism is made, the child must also be evaluated for FXS. FXS is the commonest cause of autism, and most males and few females have the characteristic autistic features of repetitive actions, flapping hands and walking on toes. ADHD is also commonly seen more in males than females with FXS. They exhibit symptoms like being constantly in motion and unable to focus on a task.

FXS can be diagnosed in the pregnant woman by amniocentesis or chorionic villi biopsy. It can be diagnosed using a blood sample or a tissue sample from the inner cheek for the presence of the defective FMR1 gene on the X chromosome. This DNA analysis uses techniques like Polymerase Chain Reaction or PCR and Southern blot analysis. Chromosomal studies identify the aberrant gene with the help of a microscope.

As of now, screening for FXS is not a part of a regular screening during pregnancy. The doctor may ask for the test if there is a history of FXS of unknown cause or mental disability in the family or in case the person is autistic or has a learning disability. Also included are women with POF (premature ovarian failure) or a family history of POF.

Fragile X Syndrome Treatment

There is no known cure for this disorder. The treatment is tailor-made according to each individual case. Broadly, it consists of:

1. Drug Therapy: Drug therapy is used to deal with some of the symptoms of Fragile X syndrome Various psychiatric medications are used to alleviate sleep problems, seizures, hyperactivity, sensory over-stimulation and mood instability. Anxiety,

depression and obsessive-compulsive disorders may co-exist along with FXS and must be promptly addressed.

2. Behaviour Therapy: This is useful in extreme cases of sensory overload to calm down the person and prevent him from getting alarmed or confused. With behaviour therapy, patients can learn to control symptoms like scratching due to inability to tolerate the texture of clothing, which may be socially inappropriate.

3. Speech Therapy: This is of immense value to teach a child various aspects of language like pronunciation, word processing and slowing down the speech. Those children who cannot speak can develop non-verbal means of communication and work with the family so that the child is not frustrated due to the inability to communicate.

4. Physical therapy: To improve motor skills used in writing, using a computer or riding a cycle, working with a physiotherapist is important. During college and adult years an occupational therapist is of benefit to identify strengths that can be turned into a skill or career in order to earn a living.

5. Educational guidance: For children with FXS enrolled in school, special coaching can be undertaken to ensure that they are on par with the rest of the class with the help of a team of specialists. Some children may need to be put in a school especially for children with similar problems.