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Investigation for RAPSN and DOK‐7 mutations in a cohort of seronegative myasthenia gravis patients
Author(s) -
Alseth Espen Homleid,
Maniaol Angelina Hatlø,
Elsais Ahmed,
Nakkestad Hanne Linda,
Tallaksen Chantal,
Gilhus Nils Erik,
Skeie Geir Olve
Publication year - 2011
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.21919
Subject(s) - myasthenia gravis , congenital myasthenic syndrome , medicine , cohort , thymectomy , neuromuscular junction , mutation , acetylcholine receptor , pediatrics , gastroenterology , genetics , biology , receptor , gene , neuroscience
Myasthenia gravis (MG) is an autoimmune disease. Patients without detectable antibodies against the nicotinic acetylcholine receptor or the muscle‐specific tyrosine kinase are referred to as seronegative MG (SNMG). Because late‐onset congenital myasthenic syndromes (CMSs) due to RAPSN or DOK7 mutations may be mistaken for SNMG, we investigated their frequency in a nationwide SNMG cohort. Methods: We performed sequencing of RAPSN and DOK7 in all Norwegian SNMG patients ( n = 74) and 37 healthy controls, examining for the N88K and c.1124_1127dupTGCC mutations, respectively. Results: We found 1 patient homozygous for N88K and 2 carriers of the N88K mutation. Sequencing of DOK7 revealed no mutations. Conclusions: This study confirms that rapsn CMS can be mistaken for SNMG. In addition, the frequency of rapsn CMS in our nationwide SNMG cohort was found to be low. SNMG patients with an atypical clinical presentation and pediatric cases should be tested for the N88K mutation before initiation of immunosuppressive drug treatment or thymectomy. Muscle Nerve, 2011