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.
Prior to its onset, patients may present with the neurological signs and symptoms of hyponatraemic encephalopathy such as nausea and vomiting, confusion, headache and seizures. These symptoms may resolve with normalisation of the serum sodium concentration. Three to five days later, a second phase of neurological manifestations occurs correlating with the onset of myelinolysis. Observable immediate precursors may include seizures, disturbed consciousness, gait changes, and decrease or cessation of respiratory function.The classical clinical presentation is the progressive development of spastic quadriparesis, pseudobulbar palsy, and emotional lability (pseudobulbar affect), with other more variable neurological features associated with brainstem damage. These result from a rapid myelinolysis of the corticobulbar and corticospinal tracts in the brainstem.In about ten per cent of people with central pontine myelinolysis, extrapontine myelinolysis is also found. In these cases symptoms of Parkinsons disease may be generated. Causes
The most common cause is overly-rapid correction of low blood sodium levels (hyponatremia). Apart from rapid correction of hyponatraemia, there are case reports of central pontine myelinolysis in association with hypokalaemia, anorexia nervosa when feeding is started, patients undergoing dialysis and burn victims. There is a case report of central pontine myelinolysis occurring in the context of refeeding syndrome, in the absence of hyponatremia.It has also been known to occur in patients suffering withdrawal symptoms of chronic alcoholism. In these instances, occurrence may be entirely unrelated to hyponatremia or rapid correction of hyponatremia.