Abstract: Objective  To investigate the relationship between single-nucleotide polymorphisms (SNPs) in the mitochondrial DNA (mtDNA) D-Loop region and the risk of laryngeal carcinoma. 
Methods  Experimental samples were collected from 71 laryngeal carcinoma patients who underwent surgery in the Department of Otolaryngology Head and Neck Surgery at the Fourth Hospital of Hebei Medical University. Samples were also collected from 159 healthy people who underwent physical examination in Medical Examination Center of our hospital. The target fragment was amplified by polymerase chain reaction (PCR), and the mtDNA D-Loop region was sequenced. The χ2 test was used to analyze the relationship between different SNPs and the risk of laryngeal carcinoma, and the relationship between the SNPs associated with laryngeal carcinoma and the clinical features of these patients was also analyzed. 
Results  SNPs in the mtDNA D-Loop region were related with the isk of laryngeal carcinoma. The genotypes of 73G, 309C, 315C and 16319G were significantly related with an increased risk in laryngeal carcinoma, whereas the genotypes of 524C, 556A, 16288T, 16291C and 16311T were associated with the lower risk of laryngeal 
carcinoma. 
Conclusion  SNPs in the mtDNA D-Loopregion can be used as predictors to improve the early diagnosis rate of laryngeal squamous cell carcinoma and guide the clinical treatment of the disease.

Key words: laryngeal neoplasms, polymorphism, single nucleotide, DNA, mitochondrial