title: Homozygous survival motor neuron 2 gene deletion and sporadic lower motor neuron disease in children: case report and literature review.
abstract: A case of lower motor neuron disease with homozygous survival motor neuron 2 (SMN2) gene deletion is reported in this article. A 7-year-old boy was admitted to our hospital with main complaints of lower extremity weakness and difficulty squatting for the past year. SMN gene copies were quantified by multiplex ligation-dependent probe amplification. Exons 7 and 8 of the SMN1 gene were normal, but homozygous deletion of exons 7 and 8 of the SMN2 gene was identified. Homozygous deletion of exons 7 and 8 of the SMN centromeric gene was detected, and exons 7 and 8 of the SMN1 gene were found to be normal in the proband. Two copies of exons 7 and 8 of the SMN1 gene were identified, and zero copies of exons 7 and 8 of the SMN2 gene were found. We consider that this case represents a previously unrecognized type of lower motor neuron disease that resulted from homozygous deletion of the SMN2 gene.
authors.affiliation: Department of Clinical Laboratory, Shengjing Hospital of China Medical University, Shenyang, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Liping
authors.forename: Ma
authors.initials: M
authors.lastname: Hongwei
authors.forename: Wang
authors.initials: W
authors.lastname: Lin
mesh_terms: D002648:Child; D004252:DNA Mutational Analysis; D017353:Gene Deletion; D006720:Homozygote; D006801:Humans; D035002:Lower Extremity / Q000473:pathology / Q000503:physiopathology; D008297:Male; D016472:Motor Neuron Disease / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D055540:Survival of Motor Neuron 2 Protein / Q000235:genetics*
chemical_list: D055540:Survival of Motor Neuron 2 Protein