Association of diabetes mellitus type I and mucopolysaccharidosis type IV A: case report

Abstract

 Introduction: Type I diabetes mellitus (DM1) is a chronic illness that results from insulin deficiency caused by the destruction of pancreatic beta cells that produce insulin via an autoimmunity mech­anism. Mucopolysaccharidoses (MPS) are genetic disorders inherited through autosomal recessive traits, caused by a deficiency of enzymes responsible for breaking down glycosaminoglycans (GAGs). MPS type IV A (Morquio Syndrome, OMIM #253000) consists of a deficiency of the enzyme N-acetyl­galactosamine- 6-sulfato sulfatase. Therefore, GAGs accumulate in lysosomes in multiple tissues and systems, leading to cellular dysfunction and clinical symptoms. Case report: A four-year-old patient was diagnosed with DM1 at the age of two, with anti-GAD and anti-insulin autoantibodies, and was un­dergoing insulin therapy. Additionally, the physical examination revealed phenotypic changes such as macrocrania, a prominent forehead, a flat nasal root, epicanthus, a short columella, a short neck, a short and bulging chest, enlarged wrists, and brachydactyly. The diagnosis involved a skeletal dysplasia panel whose results were compatible with MPS type IV A. Laboratory tests confirmed increased urinary glycosaminoglycans, and the N-acetylgalactosamine-6-sulfatase enzymatic assay confirmed the enzy­matic deficiency, ultimately confirming the diagnosis. As a result, the child received specific enzyme replacement therapy to prevent complications and provide a better prognosis. Discussion: Although rare, the differential diagnosis of young individuals with chronic hyperglycemic symptoms associated with phenotypic and functional changes should include the association of DM1 and MPS type IV.