Japanese pediatric neurologist's decision regarding genetic testing for patients with developmental delay/intellectual disability: A nationwide survey

Background

Advances in genetic analysis technology are increasing the opportunities for developmental delay/intellectual disability (DD/ID) cases to reach genetic diagnosis. However, the decision to perform genetic testing depends on the physician's decision; furthermore, the accessibility of genetic testing varies by country or region.

Methods

Japanese certified pediatric neurologists participated in an online survey from February to March 2023 to assess their attitudes toward genetic testing for DD/ID.

Results

The study enrolled 266 pediatric neurologists, including 41 certified clinical geneticists. In Japan, G-banding emerged as the most common first-line genetic testing for DD/ID. For DD/ID without physical and behavioral abnormalities, 30 % of pediatric neurologists indicated that they would not perform genetic testing compared with 15 % of clinical geneticists. 75.6 % of certified clinical geneticists reported experience submitting chromosomal microarray analysis (CMA), while only 39.2 % of pediatric neurologists had experience submitting CMA.

Conclusion

Differences in the decision of indication for genetic testing for DD/ID cases were shown to be influenced by specialized genetic training. Improved education and access to genetic specialists may help standardize genetic diagnosis in Japan. On the other hand, a standardized testing policy, especially for non-genetic specialists, is needed to make genetic testing for DD/ID more widely available.