Molecular analysis of <italic>SMN2, NAIP,</italic> and <italic>GTF2H2</italic> gene deletions and relationships with clinical subtypes of spinal muscular atrophy.

AbstractSMA (spinal muscular atrophy) is an autosomal recessive neuromuscular disease that causes muscle atrophy and weakness. SMA is diagnosed by a homozygous deletion in exon 7 of the <italic>SMN1</italic> gene. However, mutations in genes located in the SMA region, such as <italic>SMN2</italic>, <italic>NAIP, SERF1,</italic> and <italic>GTF2H2,</italic> may also contribute to the severity of the disease. Within our study’s scope, 58 SMA patients who applied in 2018–2021 and 40 healthy controls were analyzed. The study retrospectively included the SMN1 and SMN2 copy numbers previously determined by the MLPA method. Then, <italic>NAIP</italic> gene analyses with the multiplex PCR method and <italic>GTF2H2</italic> gene analyses with the RFLP method were performed. There was a significant correlation (<italic>p</italic> = 0.00001) between <italic>SMN2</italic> copy numbers and SMA subtypes. Also, the <italic>NAIP</italic> gene (<italic>p</italic> = 0.01) and the <italic>GTF2H2</italic> gene (<italic>p</italic> = 0.0049) revealed a significant difference between healthy and SMA subjects, whereas the SMA subtypes indicated no significant differences. We detected a significant correlation between clinical subtypes and HFMSE scores in 32 pediatric SMA patients compared (<italic>p</italic> = 0.01). While pediatric patients with <italic>GTF2H2</italic> deletions demonstrated higher motor functions, and those with <italic>NAIP</italic> deletions demonstrated lower motor functions. In this study, we examined the relationship between <italic>NAIP</italic> and <italic>GTF2H2</italic>, called SMN region modifier genes, and the clinical severity of the disease in Turkish SMA patients. Despite its small scale, this research will benefit future investigations into the pathogenesis of SMA disease. [ABSTRACT FROM AUTHOR]