Fragile X Syndrome (FXS)

Fragile X Syndrome (FXS) is an X-linked dominant genetic disorder, representing the most common monogenic cause of inherited intellectual disability and Autism Spectrum Disorder (ASD). Over 99% of cases result from abnormal expansion of triplet repeat sequences (CGG) on the FMR1 gene, with the remainder caused by point mutations or deletions in FMR1.
Based on the number of CGG repeat sequences, FXS variants are classified as normal (<45), intermediate (45-54), premutation (55-200), and full mutation (>200). Clinically, identifying premutation carriers, particularly in females, is crucial for reducing the risk of having children with FXS. Additionally, newborn screening for CGG repeat sequences can effectively predict disease onset and severity. FXS is listed in the "Second Batch of Rare Diseases Catalog" jointly formulated by the National Health Commission and five other departments.
AXBIO's fourth-generation sequencing platform offers advantages such as long reads, high accuracy, no GC bias, and ultra-low cost. It addresses limitations of traditional FXS gene detection methods by accurately sequencing the highly complex FMR1 gene CGG repeat region, enabling precise detection of CGG repeat numbers.