Different Clinical Faces of the Same Gene Mutation: Fragile X Mental Retardation 1 Disorders

Abstract

The fragile X mental retardation 1 gene located on the X-chromosome plays a role in protein synthesis of the same name (fragile X mental retardation protein). The normal allele of this gene has 5-40 CGG repeats, wherein >200 repeats of the same trinucleotide are called full mutations and 55-200 repeats are called premutations. These mutations cause different clinical pictures, which sometimes overlap each other, such as fragile X syndrome, fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated primary ovarian insufficiency (FXPOI), autism spectrum disorders, and attention deficit hyperactivity syndrome. These phenotypes, which make up different faces of mutations in the same gene, are grouped under the term fragile X-related diseases. The disease is more common in men; however, asymptomatic women are also affected. Therefore, careful evaluation of other family members, as well as patients, is important especially for early recognition and management of neuropsychiatric symptoms. This article aimed to emphasize the importance of evaluating family members to manage genetic diseases among the family by focusing on a 19-year-old female patient who presented with neuropsychiatric findings and FXTAS and FXPOI phenotypes.

Keywords

• fmr1 gene
• fragile x syndrome
• fmr1 disorders