Introduction: Niemann Pick Disease (NPD) is a lipid storage disorder with an autosomal recessive inheritance. The disease occurs mainly due to defects in SMPD1 gene (11p15.4), encoding sphingomyelinase. Disruption of this enzyme leads to the accumulation of sphingomyelin in brain and liver resulting in dysfunction or damage of the brain tissues.
 
Polymorphic markers such as Single Nucleotide Polymorphisms (SNPs) are used in molecular diagnosis of genetic disease through linkage analysis or homozygosity mapping. The allele frequency and degree of heterozygosity of the markers are usually population dependent. The aim of this study was to investigate the allele frequency and degree hetereozygosity of rs67992843 marker located in the SMPD1 gene region in the Iranian population.
 
Materials & methods: 113 unrelated individuals were selected for this study. The marker was genotyped using ARMS PCR with newly designed primers. The results were analyzed by Genepop database and Power Marker software to estimate allelic frequency, heterozygosity rate, presence of Hardy Weinberg Equilibrium (HWE) and polymorphism information content (PIC).
 
Findings: The data showed 31.42% Minor Allele Frequency (MAF), 39.82% heterozygosity rate and PIC 0.338 for rs67992843 marker in the Iranian population.
 
Discussion & conclusions: The results of this study showed that rs67992843 marker could be suggested for linkage analysis and molecular diagnosis of SMPD1 gene in the Iranian population.