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Decreased miniature endplate potentials

MedGen UID:
381306
Concept ID:
C1853952
Finding
Synonym: Decreased miniature endplate potentials (MEPP)
 
HPO: HP:0003402

Definition

An abnormal reduction in the amplitude of the miniature endplate potentials, i.e. the postsynaptic response to transmitter released from an individual vesicle at the neuromuscular junction. [from HPO]

Term Hierarchy

Conditions with this feature

Familial infantile myasthenia
MedGen UID:
140751
Concept ID:
C0393929
Disease or Syndrome
Congenital myasthenic syndromes (CMS) are a group of inherited disorders affecting the neuromuscular junction (NMJ). Patients present clinically with onset of variable muscle weakness between infancy and adulthood. These disorders have been classified according to the location of the defect: presynaptic, synaptic, and postsynaptic. CMS6 is an autosomal recessive CMS resulting from a presynaptic defect; patients have onset of symptoms in infancy or early childhood and tend to have sudden apneic episodes. Treatment with acetylcholinesterase inhibitors may be beneficial (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 3A
MedGen UID:
898378
Concept ID:
C4225372
Disease or Syndrome
Slow-channel congenital myasthenic syndrome (SCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the AChR channel, specifically from prolonged opening and activity of the channel, which causes prolonged synaptic currents resulting in a depolarization block. This is associated with calcium overload, which may contribute to subsequent degeneration of the endplate and postsynaptic membrane. Treatment with quinine, quinidine, or fluoxetine may be helpful; acetylcholinesterase inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Myasthenic syndrome, congenital, 1B, fast-channel
MedGen UID:
909200
Concept ID:
C4225405
Disease or Syndrome
Fast-channel congenital myasthenic syndrome (FCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor (AChR) channel, specifically from abnormally brief opening and activity of the channel, with a rapid decay in endplate current and a failure to reach the threshold for depolarization. Treatment with pyridostigmine or amifampridine may be helpful; quinine, quinidine, and fluoxetine should be avoided (summary by Sine et al., 2003 and Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital myasthenic syndrome 4A
MedGen UID:
908188
Concept ID:
C4225413
Disease or Syndrome
Slow-channel congenital myasthenic syndrome (SCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor channel, specifically from prolonged opening and activity of the channel, which causes prolonged synaptic currents resulting in a depolarization block. This is associated with calcium overload, which may contribute to subsequent degeneration of the endplate and postsynaptic membrane. Treatment with quinine, quinidine, or fluoxetine may be helpful; acetylcholinesterase inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).

Professional guidelines

PubMed

Patten BM
Muscle Nerve 1978 May-Jun;1(3):190-205. doi: 10.1002/mus.880010304. PMID: 86952

Recent clinical studies

Etiology

Rocha MC, Pousinha PA, Correia AM, Sebastião AM, Ribeiro JA
PLoS One 2013;8(9):e73846. Epub 2013 Sep 5 doi: 10.1371/journal.pone.0073846. PMID: 24040091Free PMC Article
Banwell BL, Ohno K, Sieb JP, Engel AG
Neuromuscul Disord 2004 Mar;14(3):202-7. doi: 10.1016/j.nmd.2003.11.004. PMID: 15036330
Baraka A
Middle East J Anaesthesiol 1993 Feb;12(1):9-35. PMID: 8316155
Baraka A
Can J Anaesth 1992 May;39(5 Pt 1):476-86. doi: 10.1007/BF03008713. PMID: 1596973
Engel AG, Lambert EH, Mulder DM, Torres CF, Sahashi K, Bertorini TE, Whitaker JN
Ann Neurol 1982 Jun;11(6):553-69. doi: 10.1002/ana.410110603. PMID: 6287911

Diagnosis

Régal L, Shen XM, Selcen D, Verhille C, Meulemans S, Creemers JW, Engel AG
Neurology 2014 Apr 8;82(14):1254-60. Epub 2014 Mar 7 doi: 10.1212/WNL.0000000000000295. PMID: 24610330Free PMC Article
Baraka A
Middle East J Anaesthesiol 1993 Feb;12(1):9-35. PMID: 8316155
Baraka A
Can J Anaesth 1992 May;39(5 Pt 1):476-86. doi: 10.1007/BF03008713. PMID: 1596973
Maselli RA, Richman DP, Wollmann RL
Neurology 1991 Sep;41(9):1497-504. doi: 10.1212/wnl.41.9.1497. PMID: 1891103
Patten BM
Muscle Nerve 1978 May-Jun;1(3):190-205. doi: 10.1002/mus.880010304. PMID: 86952

Therapy

Trobec T, Žužek MC, Sepčić K, Kladnik J, Kljun J, Turel I, Benoit E, Frangež R
Biomed Pharmacother 2020 Jul;127:110161. Epub 2020 May 4 doi: 10.1016/j.biopha.2020.110161. PMID: 32380389
Yoshikawa H, Iwasa K, Satoh K, Takamori M
J Autoimmun 1997 Feb;10(1):11-6. doi: 10.1006/jaut.1996.0111. PMID: 9080295
Baraka A
Middle East J Anaesthesiol 1993 Feb;12(1):9-35. PMID: 8316155
Lee DC, Kim YI, Liu HH, Johns TR
Muscle Nerve 1983 Jul-Aug;6(6):442-7. doi: 10.1002/mus.880060608. PMID: 6312309
Patten BM
Muscle Nerve 1978 May-Jun;1(3):190-205. doi: 10.1002/mus.880010304. PMID: 86952

Prognosis

Maselli RA, Arredondo J, Vázquez J, Chong JX, Bamshad MJ, Nickerson DA, Lara M, Ng F, Lo VL, Pytel P, McDonald CM
Ann N Y Acad Sci 2018 Feb;1413(1):119-125. Epub 2018 Jan 28 doi: 10.1111/nyas.13585. PMID: 29377152Free PMC Article
Banwell BL, Ohno K, Sieb JP, Engel AG
Neuromuscul Disord 2004 Mar;14(3):202-7. doi: 10.1016/j.nmd.2003.11.004. PMID: 15036330
Kishi M, Fujioka T, Miura H, Sekine A, Iguchi H, Nakazora H, Kiyozuka T, Igarashi O, Ichikawa Y, Sugimoto H, Kurihara T, Irie S, Saito T
J Peripher Nerv Syst 2003 Jun;8(2):82-90. doi: 10.1046/j.1529-8027.2003.03011.x. PMID: 12795712
Baraka A
Middle East J Anaesthesiol 1993 Feb;12(1):9-35. PMID: 8316155

Clinical prediction guides

Maselli RA, Arredondo J, Vázquez J, Chong JX, Bamshad MJ, Nickerson DA, Lara M, Ng F, Lo VL, Pytel P, McDonald CM
Ann N Y Acad Sci 2018 Feb;1413(1):119-125. Epub 2018 Jan 28 doi: 10.1111/nyas.13585. PMID: 29377152Free PMC Article
Banwell BL, Ohno K, Sieb JP, Engel AG
Neuromuscul Disord 2004 Mar;14(3):202-7. doi: 10.1016/j.nmd.2003.11.004. PMID: 15036330
Ohno K, Tsujino A, Brengman JM, Harper CM, Bajzer Z, Udd B, Beyring R, Robb S, Kirkham FJ, Engel AG
Proc Natl Acad Sci U S A 2001 Feb 13;98(4):2017-22. doi: 10.1073/pnas.98.4.2017. PMID: 11172068Free PMC Article
Maselli RA, Wollman RL, Leung C, Distad B, Palombi S, Richman DP, Salazar-Grueso EF, Roos RP
Muscle Nerve 1993 Nov;16(11):1193-203. doi: 10.1002/mus.880161109. PMID: 8105377
Nagel A, Lehmann-Horn F, Engel AG
Muscle Nerve 1990 Aug;13(8):742-9. doi: 10.1002/mus.880130813. PMID: 2166911

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