Narcolepsy-like symptoms in a patient with down syndrome and without obstructive sleep apnea

The study reports on a 33-year-old Caucasian female with Down syndrome and narcolepsy-like symptoms.

After medical and genetic screening, docturnal polysomnography followed by a Multiple Sleep Latency Test and HLA typing were performed. The patient was medication free and reported a number of cataplexy attacks everyday. Each time that she came to the sleep disorders clinic, she was observed to have cataplexy. She also felt extremely drowsy. A mean sleep latency of 8.8 minutes with 4 sleep-onset rapid eye movement periods in the Multiple Sleep Latency Test, with no other sleep disorder that accounts for the symptoms, was obtained. The patient was DQB1*0301, DQB1*0602, as revealed by the last high-resolution serologic typing.