Version 2.77

Description

Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder that is characterised by muscle weakness of the limbs. It is the result of an autoimmune reaction, where antibodies are formed against presynaptic voltage-gated calcium channels in the neuromuscular junction (the connection between nerves and the muscle that they supply). Around 60% of those with LEMS have an underlying malignancy, most commonly small cell lung cancer; it is therefore regarded as a paraneoplastic syndrome (a condition that arises as a result of cancer elsewhere in the body).

In LEMS, antibodies against voltage-gated calcium channels (VGCC), particularly the P/Q-type VGCC, decrease the amount of calcium that can enter the nerve ending, hence less acetylcholine can be mobilized to the neuromuscular junction. Apart from skeletal muscle, the autonomic nervous system also requires acetylcholine neurotransmission; this explains the occurrence of autonomic symptoms in LEMS. P/Q voltage-gated calcium channels are also found in the cerebellum, explaining why some experience problems with coordination. The antibodies bind particularly to the part of the receptor known as the "domain III S5-S6 linker peptide". Antibodies may also bind other VGCCs. Some have antibodies that bind synaptotagmin, a protein involved in calcium-regulated vesicle transport, rather than against VGCC. Many people with LEMS, both with and without VGCC antibodies, have detectable antibodies against the M1 subtype of the acetylcholine receptor; it is thought that their presence participates in a lack of compensation for the slow calcium influx. Copyright Text is available under the Creative Commons Attribution/Share-Alike License. See http://creativecommons.org/licenses/by-sa/3.0/ for details. Source: Wikipedia, Wikipedia

Basic Part Properties

Part Display Name
Voltage-gated calcium channel P/Q type binding Ab
Part Type
Component (Describes the core component or analyte measured)
Created On
2006-05-09

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https://fhir.loinc.org/CodeSystem/$lookup?system=http://loinc.org&code=LP40154-4

Language Variants Get Info

Tag Language Translation
zh-CN Chinese (China) PQ 型电压门控钙离子通道结合抗体
Synonyms: PQ 型电压门控钙离子通道结合 Ab;电压门控钙离子通道 PQ 型结合 Ab;电压门控钙离子通道 PQ 型结合抗体
pl-PL Polish (Poland) Kanały wapniowe bramkowane napięciem typu PQ.Ab
Synonyms: Przeciwciała do kanałów wapniowych typu PQ