TP53 polymorphism may contribute to genetic susceptibility to develop Hashimoto's thyroiditis

Area of Science:

• Genetics and Molecular Biology
• Immunology
• Endocrinology

Background:

• The p53 protein, encoded by the tumor suppressor gene TP53, regulates cell cycle arrest and apoptosis.
• TP53 single nucleotide polymorphisms (SNPs) have been associated with increased susceptibility to cancer and autoimmune diseases due to altered p53 apoptotic function.

Purpose of the Study:

• To investigate the genotypic distribution of TP53 exon 4 SNPs in Caucasian patients with Hashimoto's thyroiditis (HT).
• To determine if specific TP53 SNPs are associated with susceptibility to HT in a Caucasian cohort.

Main Methods:

• DNA was extracted from peripheral blood samples of 109 Caucasian individuals (79 HT patients, 30 healthy controls).
• TP53 exon 4 was analyzed for single nucleotide polymorphisms (SNPs) using amplification and sequencing.

Main Results:

• The Pro72Arg (rs 1042522) SNP showed significantly different genotype frequencies between HT patients and controls: G/C heterozygosity (24.0% vs 46.7%, p=0.039) and G/G homozygosity (64.6% vs 43.3%, p=0.042).
• Other investigated TP53 SNPs were rare or absent in the study population.
• These findings were consistent when compared to published Caucasian control groups.

Conclusions:

• Preliminary data suggest that the rs 1042522 SNP in TP53 exon 4 may influence susceptibility to Hashimoto's thyroiditis in Caucasian individuals.
• An increased prevalence of the Arg/Arg homozygous genotype and a decreased prevalence of the Arg/Pro heterozygous genotype at rs 1042522 were observed in HT patients.