Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The etiology of the Rett syndrome (RS) is unknown. Reduced function of biogenic amines has been described. Symptoms of central apnea, hyperventilation, hypothermia, peripheral analgesia, muscle rigidity, myoclonic jerks, hand stereotypy and seizures occur in RS and have been suggested as a result of elevated central beta-endorphins. It was hypothesized that a dysfunctional modulation of endogenous opiate systems and biogenic amines may be present. Cerebrospinal fluid (CSF) from 12 girls with RS was studied for beta-endorphin immunoreactivity, and biogenic amines. Lactates and pyruvate levels were measured. Eleven of the 12 girls had elevated beta-endorphin immunoreactivity in CSF, 4 girls had reduced biogenic amines and 6 girls had elevated pyruvate and lactate levels. Whether the elevated beta-endorphin immunoreactivity is a primary disorder or is a result of secondary feedback mechanisms is unknown. Naltrexone, an antiopioid drug, may reduce symptoms.
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PMID:Cerebrospinal fluid studies in the Rett syndrome: biogenic amines and beta-endorphins. 169 44

Rett syndrome is a neurological disorder of females characterized by dementia, autism, movement disorders and an abnormality of respiratory control. A 14-year-old girl with Rett Syndrome underwent spinal fusion surgery under general anaesthesia. No exacerbation of the respiratory control defect with surgery and anaesthesia was observed. Hypothermia, ongoing blood loss and a normal anion gap acidosis were encountered, but were not attributable to features of this disorder.
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PMID:Anaesthesia and Rett syndrome: a case report. 275 49

Two elderly females with Rett syndrome are reported with evidence of a slowly progressive central and distal peripheral nervous system involvement. Thermography in 4 girls confirmed distal hypothermia of the extremities in a glove and stocking distribution. Unilateral sympathectomy during surgery for scoliosis in one of them resulted in increased warmth and physical growth of the foot and nails, compared to the uninjured side. This suggests increased sympathetic tone as the probable cause of distal hypothermia, vasomotor instability and dystrophy of the feet in this disorder. In an attempt to identify a marker, girls with clinically classical Rett syndrome had plasma and urinary cell evaluation for an unusual glycolipid. A blind study using a small number of patients failed to prove absolute specificity and additional studies are required to evaluate its validity as a marker for Rett syndrome.
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PMID:Rett syndrome: new observations. 282 48

The 5q14.3 deletion syndrome is a rare chromosomal disorder characterized by moderate to severe intellectual disability, seizures and dysmorphic features. We report a 14-year-old boy with 5q14.3 deletion syndrome who carried a heterozygous deletion of the myocyte-specific enhancer factor 2c (MEF2C) gene. In addition to the typical neurodevelopmental features of 5q14.3 deletion syndrome, he showed recurrent hypoglycemia, appetite loss and hypothermia. Hormonal loading tests using insulin, arginine and growth hormone-releasing factor revealed that growth hormone was insufficiently released into serum in response to these stimuli, thus disclosing the hypothalamic dysfunction in the present case. To uncover the biological roles of MEF2C in the hypothalamus, we studied its expression in the postnatal mouse brain. Notably, neuropeptide Y (NPY)-positive interneurons in the hypothalamic arcuate nuclei highly expressed MEF2C. In contrast, the Rett syndrome-associated protein, Methyl-CpG binding Protein 2 (MECP2) was barely expressed in these neurons. MEF2C knockdown or overexpression experiments using Neuro2a cells revealed that MEF2C activated the endogenous transcription of NPY. Conversely, siRNA-mediated knockdown of MECP2 led to derepression of the Npy gene. These data support the concept that MEF2C and MECP2 share common molecular pathways regulating the homeostatic expression of NPY in the adult hypothalamus. We propose that individuals with 5q14.3 deletion syndrome may exhibit neuroendocrine phenotypes through the functional loss of MEF2C in the postnatal hypothalamus.
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PMID:Neuroendocrine phenotypes in a boy with 5q14 deletion syndrome implicate the regulatory roles of myocyte-specific enhancer factor 2C in the postnatal hypothalamus. 2383 6

Sudden unexpected death occurs in one quarter of deaths in Rett Syndrome (RTT), a neurodevelopmental disorder caused by mutations in Methyl-CpG-binding protein 2 (MECP2). People with RTT show a variety of autonomic nervous system (ANS) abnormalities and mouse models show similar problems including QTc interval prolongation and hypothermia. To explore the role of cardiac problems in sudden death in RTT, we characterized cardiac rhythm in mice lacking Mecp2 function. Male and female mutant mice exhibited spontaneous cardiac rhythm abnormalities including bradycardic events, sinus pauses, atrioventricular block, premature ventricular contractions, non-sustained ventricular arrhythmias, and increased heart rate variability. Death was associated with spontaneous cardiac arrhythmias and complete conduction block. Atropine treatment reduced cardiac arrhythmias in mutant mice, implicating overactive parasympathetic tone. To explore the role of MeCP2 within the parasympathetic neurons, we selectively removed MeCP2 function from cholinergic neurons (MeCP2 ChAT KO), which recapitulated the cardiac rhythm abnormalities, hypothermia, and early death seen in RTT male mice. Conversely, restoring MeCP2 only in cholinergic neurons rescued these phenotypes. Thus, MeCP2 in cholinergic neurons is necessary and sufficient for autonomic cardiac control, thermoregulation, and survival, and targeting the overactive parasympathetic system may be a useful therapeutic strategy to prevent sudden unexpected death in RTT.
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PMID:Methyl-CpG binding-protein 2 function in cholinergic neurons mediates cardiac arrhythmogenesis. 2815 85