Association Between HLA Antigens and Different Types of Hypersomnia

Abstract

<h3>To the Editor.—</h3> A close association has been reported between HLA antigens and narcolepsy.^1-3Over the past two years we compared various types of hypersomnia in 56 patients. Thirty-four narcoleptics and 13 patients with idiopathic central nervous system hypersomnia, all unrelated and white, were included in the statistics (Table). These patients were diagnosed on the basis of a clinical interview and polygraphic recordings of at least five daytime naps. Polygraphic recordings were scored blind with regard to the results of HLA determinations. All narcoleptics exhibited excessive daytime sleepiness, cataplexy, and sleep-onset rapid eye movement periods during nap recordings. All idiopathic hypersomniacs had severe excessive daytime sleepiness without cataplexy and short sleep latencies but no sleep-onset rapid eye movement periods during naprecordings. Sleep apnea and nocturnal myoclonus were ruled out in all idiopathic hypersomniac patients by two all-night polygraphic recordings. Fifty-four HLA antigens of loci A, B, C, and