To investigate the etiology of anemia and recurrent epistaxis in a Chinese boy, we conducted a comprehensive blood morphological examination. Whole-exome sequencing (WES) was performed to identify potential pathogenic variants. Gas chromatography-mass spectrometry (GC-MS) was used to measure plasma phytosterols. Peripheral blood film analysis revealed stomatocytosis and large platelets. A novel homozygous missense variant (c.680T>C; p. Leu227Pro) was identified in the ABCG8 gene. GC-MS demonstrated significantly elevated plasma phytosterol levels. In vitro minigene assays indicated that this variant may disrupt ABCG8 mRNA splicing. This study suggests that abnormal blood morphology can hint at potential inherited metabolic disorders; however, a definitive diagnosis requires genetic testing and specific biochemical indicators. Exonic variants may not only alter single nucleotides but also affect splicing. Our findings expand the spectrum of pathogenic ABCG8 variants.
KW - ABCG8 KW - sitosterolemia KW - stomatocytes KW - anemia KW - large platelets DO - 10.20517/jtgg.2026.65 UR - https://dx.doi.org/10.20517/jtgg.2026.65