Awareness and knowledge of pediatricians regarding genetic testing for Fragile X syndrome in Japan: A National Survey of Pediatricians Managing Developmental Delay/Intellectual disability

Background

Fragile X syndrome (FXS) commonly cause developmental delay, intellectual disability, and autism spectrum disorder. Although genetic testing has been available and included in Japan's national health insurance since 2016, the number of cases diagnosed with FXS remains low. This study aimed to explore the levels of awareness and understanding of FXS among pediatricians managing developmental delay/ intellectual disability in Japan, particularly between pediatrician with and without clinical genetics certification (or clinical experience with FXS).

Methods

A survey involving 1217 certified pediatric neurologists from the Japanese Society of Pediatric Neurology and 367 members of the Japanese Society of Pediatric Genetics was conducted. Additional participants were recruited from an online mailing list of 1469 pediatric neurologists. The survey comprised questions on demographics, knowledge about FXS, and genetic testing practices. The responses were analyzed using Chi-square and Fisher's exact tests, and a p-value <0.05 was considered statistically significant.

Results

Out of 386 respondents, 326 had experience ordering some kind of genetic testing, including 78 certified clinical geneticists. Knowledge gaps were significant between clinical geneticists and non-genetic specialists. While 20 % of non-genetic specialists were unaware of insurance-covered FXS genetic testing, this percentage was lower among those with clinical experience in FXS cases. Many respondents, irrespective of certification, struggled to determine the indications for requesting FXS genetic testing. Furthermore, non-genetic specialists reported more difficulty providing genetic counseling owing to the psychological burden on mothers.

Conclusion

This study highlights the necessity for expanding education and training on FXS among pediatricians in Japan. Addressing these knowledge gaps may enhance FXS diagnostic rates and improve the management of affected individuals and families. Future efforts should focus on strengthening the collaboration between clinical geneticists and general pediatricians and establishing reliable genetic counseling support systems.