Abstract

A 45 year old woman presenting with periodic hypersomnia for 17 years is reported on. She would sleep for three weeks followed by the same period awake. Polysomnography in the somnolent period disclosed an excess of total sleeping time with remarkably increased stage 1, 3/4, and REM sleep, without cataplexy or sleep paralysis. HLA typing was incompatible with narcolepsy or REM sleep behavioural disorder. Her chromosomes showed premature centromere division with chromatid puffing in areas of constitutive heterochromatin, which is exclusively found in the syndrome of infants termed Roberts’ syndrome/SC phocomelia. Other laboratory findings were not normal. It is suggested that the present case is a novel sleep disorder related to a unique chromosomal aberration.