[Dehydrated hereditary stomatocytosis in 23 cases: a single-center retrospective cohort study from Peking Union...

Objective: Dehydrated hereditary stomatocytosis (DHS), a rare condition caused by pathogenic PIEZO1 or KCNN4 mutations, remains under-recognized. This study aimed to improve the diagnosis and management of DHS in China by retrospectively analyzing clinical and genetic characteristics. Methods: Patients diagnosed with DHS at Peking Union Medical College Hospital between 2018 and 2024 were included. All had suspected congenital hemolytic anemia and were confirmed by next-generation sequencing to harbor pathogenic PIEZO1 or KCNN4 mutations. Clinical features, genotypes, iron overload, and treatment outcomes were collected and analyzed. Results: Twenty-three DHS patients were identified, including 21 with PIEZO1 and 2 with KCNN4 mutations. Common manifestations were splenomegaly, jaundice, cholelithiasis, and secondary iron overload. Mild and moderate anemia occurred in 8.7% and 17.4% of patients, respectively, and stomatocytes were present in only 17.4%. The median time from symptom onset to diagnosis was 11 years. The predominant PIEZO1 variants were c.7367G > A and c.6328C > T, with nine novel mutations identified. Both KCNN4 mutations involved c.1055G > A. No clear genotype-phenotype correlation was observed. Secondary hepatic iron overload was found in 21.7% of patients. Conclusion: DHS is often underdiagnosed or misdiagnosed. Genetic testing enables accurate identification, and regular monitoring for secondary hepatic iron overload is crucial for long-term management.