A novel technique to measure intellectual disability in patients with fragile X syndrome has been devised at the University of California, Davis.
Fragile X syndrome is the most common form of inherited intellectual impairment.
Nearly one third of patients diagnosed with fragile X syndrome also have some degree of autism, and the mutation underlying fragile X syndrome is the most commonly known single gene cause of autism.
The research team claim to have developed specific and quantitative means of measuring levels of the fragile X mental retardation 1 (FMR1) protein (FMRP), which is mutated in fragile X syndrome.
Fragile X syndrome is caused by low levels of the FMRP protein, which is thought to play a role in communication between nerve cells.
Presently, tests for fragile X syndrome determine the presence of the mutation by measuring the number of repeats at the DNA and mRNA level.
Dr. Paul Hagerman and colleagues at the University of California, Davis developed a sensitive and highly specific test for FMRP protein.
The method used is able to detect protein throughout the biologically-relevant range of protein concentrations and is readily adaptable for large-scale use.
According to Iwahashi et al "[this] method should prove to be a powerful tool for further investigation of the relationships between FMRP and the diverse clinical phenotypic domains [of fragile X syndrome].
" Such domains include not only autism and autism spectrum disorders, but also developmental delay, behavioral difficulties, anxiety, ADHD, and mood. Involvement among carriers of smaller (premutation) alleles can also involve developmental delays and/or autism spectrum disorders."
The study appears in the Journal of Molecular Diagnostics.