The frontiers of sequencing in undiagnosed neurodevelopmental diseases.

Characterized by impairments in brain and central nervous system development, neurodevelopmental diseases causes are highly heterogeneous. Although many of these diseases are individually rare, collectively more than 3% of the children are reported to be affected with a type of neurodevelopmental diseases worldwide, and many remain undiagnosed even with current genomic tools. Identifying the genetic causes of these diseases allows better clinical management and expands our understanding of human neurodevelopment. Over the past decade, expansion of genomic sequencing and some methodologic improvements have improved molecular diagnostic yield as well as the discovery of novel genetic causes for wide spectrum of neurodevelopmental diseases. Here we review the current diagnostic workflow and propose ways of improving the diagnostic yield.