Patients with SLC6A5 mutations were significantly more likely to have had recurrent infantile apnoeas (RR1.9; P < 0.005) than those with GLRA1 mutations.
We suggest that determination of BChE activity and phenotype by the micro automated method is well suited to pre-operative screening and detection of at-risk of prolonged apnea in persons receiving succinylcholine in the healthy population of western Iran.
This present study provides an additional piece of support to the hypothesis that the ChF1 and ChS1 are alleles determining the synthesis of usual and atypical cholinesterase together with the likelihood of ChU1ChD1 heterozygotes having occasional suxamethonium apnoea.
Decreased activity of plasma cholinesterase is responsible for prolonged apnea during anesthesia using neuromuscular blockers such as suxamethonium and mivacurium.
The present report represents the 1st case in which a peripheral nerve stimulator has been used to substantiate the increased succinylcholine sensitivity of a patient heterozygous for the silent and the fluoride-resistant gene, and the 2nd published case of prolonged apnea following succinylcholine in a patient carrying the Ef1 Es1 genotype for abnormal serum cholinesterase.
Whole blood cholinesterase levels decreased to less than 10% of the original value by 15 min post WoundStat™ treatment and gradually decreased until the onset of apnoea or until euthanasia.
The clinically most important variant is atypical (D70G) BChE because people with this variant have 2 hours of apnea after receiving a dose of succinylcholine that is intended to paralyze muscles for 3-5 minutes.
An atypical form of butyrylcholinesterase or the absence of its activity leads to prolonged apnea following administration of the muscle relaxant suxamethonium.
By routine preoperative blood examination, 92 of 100 cases of suxamethonium apnoea resulting from a genetic abnormality of plasma cholinesterase can be anticipated.
Mutations in human CHAT cause a congenital myasthenic syndrome due to impaired synthesis of ACh; this severe variant of the disease is frequently associated with unexpected episodes of potentially fatal apnea.
For example, electrophysiologic studies in patients suffering from sudden episodes of apnea pointed to a defect in acetylcholine resynthesis and CHAT as the candidate gene (Ohno et al., Proc Natl Acad Sci USA 98:2017-2022, 2001); refractoriness to anticholinesterase medications and partial or complete absence of acetylcholinesterase (AChE) from the endplates (EPs) has pointed to one of the two genes (COLQ and ACHE ( T )) encoding AChE, though mutations were observed only in COLQ.
Mutations in the acetylcholine transferase (CHAT) gene cause a pre-synaptic CMS, typically associated with episodic apnoea and worsening of myasthenic symptoms during crises caused by infections, fever or stress.
Mutations in <i>CHAT</i>, encoding choline acetyltransferase, cause congenital myasthenic syndrome with episodic apnea (CMS-EA), a rare autosomal recessive disease characterized by respiratory insufficiency with cyanosis and apnea after infections, fever, vomiting, or excitement.