Fragile X syndrome (FXS)

Question 1

Features

Answer 1

The most common inherited cause of development disability known

• and should always be considered.

FXS presents as a classic physical phenotype with:

• large prominent ears
• long narrow face
• macro-orchidism
• intellectual disability.

Question 2

Diagnosis

Answer 2

Cytogenic test (karyotyping): screening tests

• e.g. reproductive screening

DNA test (specific for full mutation as well as carriers)

Question 3

Management

Answer 3

Careful genetic appraisal and counselling

Assessment of child’s capabilities

Multidisciplinary assessment inc. developmental disability unit

Referral for integration of speech and language therapy, special education, behaviour management

Pharmacological treatment of any epilepsy, or attention or mood behaviour disorders

Medications may determine whether the child remains in the community or not