%0 Case Reports
%T Genetic analysis of a family affected by congenital myasthenic syndrome due to a Novel mutation in the SLC5A7 gene.
%A Tian S
%A Sun H
%A Gao FF
%A Zhang K
%A Nan J
%A Niu M
%A Jia X
%A Xu G
%A Ge W
%J BMC Neurol
%V 24
%N 1
%D 2024 Jun 17
%M 38886633
%F 2.903
%R 10.1186/s12883-024-03716-x
%X <B>BACKGROUND: </B>Mutations in the SLC5A7 gene cause congenital myasthenia, a rare genetic disorder. Mutation points in the SLC5A7 gene differ among individuals and encompass various genetic variations; however, exon deletion variants have yet to be reported in related cases. This study aims to explore the clinical phenotype and genetic traits of a patient with congenital myasthenic syndrome due to SLC5A7 gene variation and those of their family members.<BR><B>METHODS: </B>We describe a case of a Chinese male with congenital myasthenic syndrome presenting fluctuating limb weakness. Genetic testing revealed a heterozygous deletion mutation spanning exons 1-9 in the SLC5A7 gene. QPCR confirmed a deletion in exon 9 of the SLC5A7 gene in the patient's mother and brother. Clinical symptoms of myasthenia improved following treatment with pyridostigmine.<BR><B>CONCLUSIONS: </B>Exons 1, 5, and 9 of the SLC5A7 gene encode the choline transporter's transmembrane region. Mutations in these exons can impact the stability and plasma membrane levels of the choline transporter. Thus, a heterozygous deletion in exons 1-9 of the SLC5A7 gene could be the pathogenic cause for this patient. In patients exhibiting fluctuating weakness, positive RNS, and seronegativity for myasthenia gravis antibodies, a detailed family history should be considered, and enhanced genetic testing is recommended to determine the cause.