cataplexy

plural cataplexies

1. countableuncountablemedicineAn abrupt loss of muscle tone, sometimes associated with narcolepsy.

   1 more example

   Narcolepsy has been associated with the human leukocyte antigen (HLA) system, a 4-megabase region of chromosome 6, which is divided into three subregions: class I, class II, and class III. Class II HLA antigens have been strongly associated with autoimmune diseases. The class II antigen, DQB1*0602, has been associated with narcolepsy. Most (90%-100%) patients with narcolepsy/cataplexy across all ethnic groups have this allele. In addition, 35% to 56% of patients who have narcolepsy without cataplexy also have this allele. However, 20% of the normal population also has the allele, reducing its usefulness in diagnostic testing.

   2013 May 1, James M. Parish MD, FCCP, “Genetic and Immunologic Aspects of Sleep and Sleep Disorders”, in Chest, volume 143, number 5, →DOI, pages 1489–1499