Common Single Nucleotide Polymorphism of TMPRSS6, an Iron Regulation Gene, Associated with Variable Red Blood Cell Indices in Deletional α-Globin Genotypes

Abstract

Red blood cell (RBC) indices, including mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH), have been widely used for primary screening for thalassaemia (thal) syndromes. Recently, a single nucleotide polymorphism (SNP) rs855791 of TMPRSS6, an iron regulation gene involved in the substitution of a nucleotide between thymine (T) and cytosine (C) in exon 17 resulted in an amino acid change, p.Val736Ala (V736A), has been described to associate with RBC indices. The objective was to study the effects of common SNP V736A on RBC indices in deletional α-thal variations. SNP rs855791 genotypes were identified from 433 Thai volunteers, including 32.6% males and 67.4% females with an average age of 23.0 ± 8.7 years. These populations included individuals (82.4%) who had normal globin genotype (αα/αα, ββ) and α-thal carriers, which were divided into two subgroups, including α+-thal (-α/αα) (14.1%) and αo-thal (--/αα) (3.5%). Among three SNP genotypes, the C allele gradually expressed higher MCV and MCH than those of the T allele in both α+- and αo-thal traits. Importantly, SNP rs855791 of TMPRSS6 responded to α-globin deletions for sustaining RBC sizes and haemoglobinisation in α-thal carriers.

Maternal <i>TMPRSS6</i> Gene Polymorphism rs855791SNP in Women with Preeclampsia

“…Recently, the Genome-Wide Association (GWA) studies identified several Single Nucleotide Polymorphisms (SNPs) of the TMPRSS6 genes, and it was found that the rs855791 has strong robust relation with microcytic red blood cell phenotype [28]. The SNP occurs at nucleotide position 2207 of TMPRSS6 exon 17, causing a missense mutation from Valine (V) to Alanine (A) as GTC > GCC; V736A [29]. The three SNP genotypes are T allele (T/T), homozygous C allele (C/C), and heterozygous C/T.…”