Genetic Analysis of Tyrosinemia Type 1 and Fructose-1, 6 Bisphosphatase Deficiency Affected in Pakistani Cohorts

Abstract

<b>Background:</b> Inborn errors of metabolism are inherited disorders that present in early childhood and are usually caused by monogenic recessive mutations in specific enzymes that metabolize dietary components. Distinct mutations are present in specific populations.<b>Objective:</b> To determine which genomic variants are present in Pakistani cohorts with hepatorenal tyrosinemia type 1 (HT1) and fructose 1,6-bisphosphatase deficiency (FBPD).<b>Materials and Methods:</b> We sequenced the fumaryl acetoacetate hydrolase encoding gene (<i>FAH</i>) including flanking regions in four unrelated HT1 cohorts and the fructose 1,6-bisphosphatase gene (<i>FBP1</i>) in eight FBPD cohorts.<b>Results:</b> We mapped two recessive mutations in <i>FAH</i> gene for HT1; c.1062 + 5G > A(IVS12 + 5G > A) in three families and c.974C > T(pT325M) in one. We identified three mutations in <i>FBP1</i> gene; c.841G > A(p.E281K) in five FBPD families, c.472C > T(p.R158W) in two families and c.778G > A(p.G260R) in one.<b>Conclusion:</b> Knowledge of common variants for HTI and FBDP in our study population can be used in the future to build a diagnostic algorithm.