Unveiling the Gray: A Rare Case of Gray Platelet Syndrome With Hepatomegaly and Immune Dysregulation in a 14-Year-Old

Gray platelet syndrome (GPS) is a rare inherited platelet disorder characterized by the presence of gray platelets on blood smears, resulting from a deficiency of α-granules. The thrombocytopenia presents in a spectrum of bleeding tendencies, varying among different patients. We present a case of a 14-year-old male presenting with recurrent epistaxis, thrombocytopenia, hepatosplenomegaly, and recurrent infections that had not been diagnosed previously. Whole-exome gene sequencing revealed a homozygous likely pathogenic splice-site variant in the NBEAL2 gene, confirming the diagnosis of GPS, which is inherited in an autosomal recessive manner due to biallelic variants in NBEAL2. The patient had atypical hepatomegaly and low lymphocyte and monocyte counts, findings consistent with emerging evidence that GPS affects multiple hematopoietic lineages. It also contributes to immune dysregulation and results in increased susceptibility to autoimmune disorders, highlighting the need for guidelines to screen for autoimmune complications in GPS patients.