Molecular basis of anti-CD36 alloimmunization: transcriptomic evidence linking intronic splice-site mutations to CD36 loss-of-function.

Background: CD36 deficiency is a genetic disorder that can lead to fetal/neonatal alloimmune thrombocytopenia or platelet transfusion refractoriness. While CD36 deficiency caused by exonic mutations are well established, the RNA splicing mechanism by intronic mutations remains poorly defined. Methods: CD36 deficiency patients were analyzed by long-read sequencing and haplotype analysis. RNA sequencing and allele-specific analysis validated mutation-splicing associations in patients. CD36 aberrant transcript plasmids were constructed and assessed by flow cytometry. Exome sequencing of healthy donors determined mutation frequencies. Results: We found that population screening revealed a carrier frequency of approximately 2/800 for c.430-1G>C mutation and ~3/800 for c.429 + 3 Conclusion: This study establishes that intronic mutations alone can also induce CD36 deficiency by impairing mRNA splicing, thereby extending the known mutational landscape of CD36 deficiency and reinforcing the necessity of screening intronic mutations in diagnostic and pathogenetic investigations.