An Australian study (2004) of overdose admissions between 1987 and 2002 found alprazolam, which happens to be the most prescribed benzodiazepine in Australia and the United States, to be more toxic than diazepam and other benzodiazepines. They also cited a review of the Annual Reports of the American Association of Poison Control Centers National Data Collection System, which showed alprazolam was involved in 34 fatal deliberate self-poisonings over 10 years (1992–2001), compared with 30 fatal deliberate self-poisonings involving diazepam. In a New Zealand study (2003) of 200 deaths, Zopiclone, a benzodiazepine receptor agonist, had similar overdose potential as benzodiazepines. Pathophysiology
Benzodiazepines bind to a specific benzodiazepine receptor, thereby enhancing the effect of the neurotransmitter gamma-aminobutyric acid (GABA) and causing CNS depression. In overdose situations this pharmacological effect is extended leading to a more severe CNS depression and potentially coma  or cardiac arrest. Benzodiazepine-overdose-related coma may be characterised by an alpha pattern with the central somatosensory conduction time (CCT) after median nerve stimulation being prolonged and the N20 to be dispersed. Brain-stem auditory evoked potentials demonstrate delayed interpeak latencies (IPLs) I-III, III-V and I-V. Toxic overdoses of benzodiazepines therefore cause prolonged CCT and IPLs. Diagnosis
The diagnosis of benzodiazepine overdose may be difficult, but is usually made based on the clinical presentation of the patient along with a history of overdose. Obtaining a laboratory test for benzodiazepine blood concentrations can be useful in patients presenting with CNS depression or coma of unknown origin.
Cytokine receptor-like factor 1 is a protein that in humans is encoded by the CRLF1 gene. Function
This gene encodes a member of the cytokine type I receptor family. The protein forms a secreted complex with cardiotrophin-like cytokine factor 1 and acts on cells expressing ciliary neurotrophic factor receptors. The complex can promote survival of neuronal cells. Clinical significance
Mutations in this gene are associated with two conditions, both rare:

Cold-induced sweating syndrome, characterized by profuse hyperhidrosis in cold environmental temperature and characteristic craniofacial and skeletal features)
Crisponi syndrome (CS), characterized by neonatal-onset paroxysmal muscular contractions, abnormal function of the autonomic nervous system and craniofacial and skeletal manifestations such as thick and arched eyebrows, a short nose with anteverted nostrils, full cheeks, an inverted upper lip and a small mouth.It is unknown whether the two conditions are distinct clinical entities or a single clinical entity with variable expressions. Other characteristic features in CRLF1 mutation include marfanoid habitus with progressive kyphoscoliosis and craniofacial characteristics including dolichocephaly, a slender face with poor expression, a nose with hypoplastic nares, malar hypoplasia and prognathism. References
Further reading
External links
GeneReviews/NCBI/NIH/UW entry on Cold-Induced Sweating Syndrome including Crisponi Syndrome
OMIM enries on Cold-Induced Sweating Syndrome including Crisponi Syndrome
Human CRLF1 genome location and CRLF1 gene details page  in the UCSC Genome Browser.This article incorporates text from the United States National Library of Medicine, which is in the public domain.