spectrum disorder (ASD). Comprehensive and multidisciplinary evaluation of patients with ID or ASD is essential for

prudent management of any probable underlying condition. Herein we report a 4 years and 3 months old boy with

speech delay, previously admitted to other clinics many times without any definite diagnosis. Physical examination

revealed that he had hyperactivity, poor eye contact and dysmorphic features. He had global developmental delay and

symptoms of ASD. The patient who had dysmorphic features was referred to pediatric genetics department with the

suspicion of FXS. Southern Blot analysis revealed CGG repeat expansion in the range of full mutation. Maternal southern

blot analysis revealed expanded CGG repeat in the range of premutation, and the family was given genetic counseling.

The patient is still being followed-up at the developmental pediatrics department with an individual education program

and other supportive treatments.

Children with FXS typically present with developmental delay. Although motor delays are often seen, these tend to be

mild, and affected males most commonly come to hospital because of speech delay as the patient in this case. The

present patient has both FXS and ASD diagnosis. As children with FXS may not have gross physical features, any child

who has developmental delay, borderline intellectual abilities, ID or ASD with an unknown etiology should undergo

molecular testing for fragile X syndrome. It was aimed in this case to emphasize the importance of comprehensive and

multidisciplinary evaluation of all patients referred with speech delay.

Keywords: Autism spectrum disorder, Fragile X syndrome