Related Experiment Video
Updated: Dec 6, 2025

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
A strange New Year's Eve: triggers in Kleine-Levin syndrome
Garance Vaillant1,2,3, Marie Martin4, Elisabeth Groos1,2
1National Reference Center for Kleine-Levin Syndrome, Paris, France.
Abstract:
Kleine-Levin syndrome is a rare neurological disease of unknown cause beginning typically during adolescence, characterized by remittent-relapsing episodes of severe hypersomnia associated with cognitive and behavioral disturbances. Triggering factors at Kleine-Levin syndrome onset include infection, sleep deprivation, as well as alcohol, drug, and substance intake. A young woman had 6 episodes over 2 years, including hypersomnia, confusion, derealization, cognitive impairment, anxiety, feeling of being scrutinized, anorexia (and sweet craving once) but no hypersexuality. The first episode started after a party where she experienced a complete, 4-hour-long blackout despite moderate alcohol intake. The patient suspected having been poisoned. Twenty-five months after the party, when Kleine-Levin syndrome was eventually diagnosed, her long hair was analyzed and exogenous γ-hydroxybutyrate was found in the tips (corresponding to the party time). This case illustrates the interest of looking for γ-hydroxybutyrate in the hair when Kleine-Levin syndrome starts after a party.
Related Concept Videos
Inborn Errors of Metabolism
Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
ATP Synthase: Structure
Cystic Fibrosis: Pathogenesis
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation,...
Pleiotropy
Transducer Mechanism: Enzyme-Linked Receptors
Major types that are helpful drug targets include:

