Unveiling the Unexpected: Refractory Rickets as an Uncommon presentation of Tyrosinemia Type I

Background Tyrosinemia type I is a rare autosomal recessive genetic metabolic disorder characterized by lack of the enzyme fumarylacetoacetate hydrolase (FAH), which is needed for the final break down of the amino acid tyrosine, resulting in accumulation of certain metabolic intermediates in tyrosine catabolic pathway primarily causing liver disease, but also affecting kidneys and brain. Tyrosinemia Type I diagnosis is usually made in infancy with acute or chronic liver failure. Refractory Rickets is rarely described as the presenting feature in the literature. Here, we report a case of Tyrosinemia Type I presenting with refractory rickets and hepatosplenomegaly but without liver-dysfunction. Case Presentation A three year old child presented with bilateral limb deformities, for which child had received multiple therapeutic doses of Vitamin D and calcium, but with no response. On detailed history taking child also had floppiness, polyuria and polydipsia. On focused clinical examination child was noted to have hepatomegaly, and hence was evaluated and diagnosed to have hypophosphatemic rickets with Tyrosinemia type I. Child was started on phosphate supplement, specific diet and Nitisinone, and is doing well on follow up. Conclusion We are reporting the case to emphasize the importance of early recognition of hypophosphatemic rickets and to suspect tyrosinemia in children presenting with hypophophatemic rickets with liver involvement as Tyrosinemia Type I is associated with high morbidity and mortality, and early initiation of treatment is imperative to prevent mortality.