SMPD1 gene variants in patients with β-Thalassemia major

BACKGROUND: β-thalassemia major and Niemann-Pick diseases have similar clinical and laboratory findings. We aimed to investigate the effects of sphingomyelin phosphodiesterase 1 (SMPD1) gene variants on the clinical and laboratory findings in patients with β-thalassemia major. METHODS AND RESULTS: This study included 45 patients who were followed up for β-thalassemia major in our clinic. Plasma chitotriosidase, leukocyte acid sphingomyelinase, liver enzymes, ferritin, hemogram, biochemical parameters, SMPD1 gene variant analysis, cardiac T2* MRI, and liver R2 MRI were assessed in all patients. The SMPD1 gene c.132_143del, p.A46_L49del (c.108GCTGGC[4] (p.38AL[4])) (rs3838786) variant was detected in 9 of 45 (20.0%) patients. Plasma chitotriosidase, ferritin, acetyl aminotransferase, and alanine aminotransferase levels were significantly higher in patients with the gene variant than in those without (p < 0.05). Leukocyte acid sphingomyelinase levels were significantly lower in patients with the gene variant than in those without (p < 0.05). CONCLUSION: These results imply that the clinical and laboratory findings and some features of disease progression in patients with β-thalassemia major are similar to those of Niemann-Pick disease. They also suggest that SMPD1 gene c.132_143del, p.A46_L49del (c.108GCTGGC[4] (p.38AL[4])) (rs3838786) variant may underlie these clinical findings in patients with β-thalassemia major.