Abstract
Inherited thrombocytopenias (ITs) are a diverse group of hematological disorders. This study reports a novel case of severe thrombocytopenia in two male twins from nonconsanguineous parents. Whole exome sequencing (WES) identified a heterozygous genetic variant (c.1766T > C; p.L589S) in the helicase domain of the SLFN14 gene in the twins, their mother, and maternal grandmother, while the father and maternal grandfather did not carry the genetic variant. Despite carrying the genetic variant, the mother and maternal grandmother showed no abnormal phenotypes. The twins exhibited significantly reduced platelet counts, abnormal megakaryocyte accumulation, and arrested maturation, broadening the spectrum of SLFN14-related thrombocytopenia. Clinical Trial Registration: The authors confirm that registration of a clinical trial is not necessary for this submission.