Objectives: To assess paediatricians' use of genetic testing for children with global developmental delay (GDD).
Study design: We developed and piloted a questionnaire assessing the use of genetic tests in children with GDD and awareness of relevant guidelines. All practicing Quebec paediatricians were contacted. Paediatricians who did not evaluate children with GDD in their practice were excluded. Descriptive and statistical analyses were performed with SPSS.
Results: Of the 651 paediatricians, 225 answered (34.5%) and 141 were eligible. Only 31.9% were familiar with at least one guideline about genetic tests for the investigation of children with GDD, but 93.6% had ordered genetic testing for children with GDD (Fragile X testing [92.9%], karyotype [87.2%] and chromosomal microarray [63.8%]). Based on vignettes, 20.6% of participants would order genetic tests for isolated GDD and 95.0% for GDD with dysmorphic features and microcephaly. Only 56.7% ordered Fragile X testing for a girl with GDD and a known family history of Fragile X syndrome. Use of tests for isolated GDD was increased in presence of maternal pregnancy, compared with absence of pregnancy (44.7% and 27.7%, respectively). More participants would order genetic tests for a child with GDD and fetal exposure to alcohol (69.5%) than isolated GDD (20.6%).
Conclusions: Even though paediatricians often order genetic testing for children with GDD, practices and knowledge regarding testing are not optimal. As new and more complex genetic tests are developed, up-to-date training about the use of genetic tests for children with GDD needs to be integrated into paediatrics residency programs and continuous medical education.
Keywords: Bioethics; Chromosomal microarray; Clinical ethics; Fragile X; Genetic testing; Global developmental delay.