In current study, we discuss clinical oral iron refractoriness cases and highlight need for a classification system to define TMPRSS6 gene variants. Out of 231 cases of microcytic hypochromic anemia screened (Sept 2019-Dec 2020), 17 cases (7.35%) with unexplained iron refractoriness (URIDA) phenotype were enrolled after ruling out secondary causes and compliance related issues. 11 (65%) had absent/negligible response (0-0.4 g/dl Hb rise) while 6 (35%) partial (0.5-0.9 g/dl Hb rise) response to initial iron trial at 4-8 weeks. Of these 17 cases, inappropriate hepcidin levels (normal-high) were noted in 11/15 (73%) tested. TSAT/Hepcidin ratio was low in 13/15 (87%). Genetic analysis of TMPRSS6 gene by NGS revealed variations in 15/17 (88%) cases. 10/15 cases with variations harbored a common splice site INDEL that was noted to be pathogenic SNP (MAF-0.19) on case-control association study in combination with other known missense SNPs with an odds ratio of 6.38 and relative risk 2.66 (p- < 0.01).
Keywords: Iron; SNPs; TMPRSS6; URIDA.
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