Merging evans syndrome with mucopolysaccharidosis type II: a case report

Mucopolysaccharidosis type II (MPS II) is an X-linked recessive lysosomal storage metabolic disorder caused by pathogenic mutations in the iduronate-2-sulfatase (IDS) gene. Herein, we report the case of a 2-year-old male patient diagnosed with concurrent Evans syndrome (ES) and MPS II, who presented with severe anemia, thrombocytopenia, recurrent respiratory tract infections, and typical clinical manifestations of MPS II. Laboratory examinations showed decreased hemoglobin (Hb) and platelet (PLT) counts, a positive direct Coombs test, presence of anti-platelet antibodies, elevated urinary glycosaminoglycan levels, and complete absence of IDS enzyme activity. Whole exome sequencing identified a novel compound heterozygous nonsense mutation in the IDS gene: c. 380₃83dup GCTA, p. Y128X. The patient received hematopoietic stem cell transplantation (HSCT) and underwent long-term follow-up. During the follow-up period, the patient's IDS enzyme activity returned to normal levels, and no further recurrence of ES was observed. This study reports a novel pathogenic mutation of the IDS gene, and represents the first documented case of concurrent ES and MPS II in a toddler. HSCT has been confirmed to be an effective therapeutic strategy for this extremely rare comorbid condition. Additionally, we discuss the potential pathogenic association between mucopolysaccharidosis (MPS) and ES, and present a systematic summary of the clinical management of this patient, to provide a reference for improved identification and treatment of similar clinical cases in the future.