Trisomy 21 in forensic autopsies: Review of a 20-year period.

•Forensic autopsy cases of decedents with trisomy 21 are very rare (0.14% of all autopsy cases during a 20-year-period).•In 69.6% of the cases, the manner of death was classified as natural with fatal infections being the main cause of death. The study did not reveal any homicidal or suicidal deaths.•When assessing allegations of medical malpractice, the higher susceptibility, and the higher risk for fatal courses of presumed uncomplicated e.g. respiratory infections in patients with trisomy 21 must be kept in mind.