MMAB and autism: The connection between stuttering and sleep is further supported by a recent large-scale multi-ancestry GWAS meta-analysis of short and long sleep duration95, which identified five genes associated with sleep duration that overlap with our stuttering findings: PTPB2, SRPK2, KCTD10, MMAB and SLC39A8. In addition, for traits without available sex-stratified summary statistics, genetic correlation analysis revealed increased risk of autism and impaired beat synchronization.