First Family Case of Hemoglobinopathy Titusville in China with Falsely Low SpO2 and Unmeasurable SaO2.

BACKGROUND: Normal hemoglobin is a tetrameric structure, consisting of two alpha-globin chains and two nonalpha (beta, gamma, delta) chains. Hemoglobinopathies occur when the presence of gene mutations affect the molecular structure or expression of the globin chains.

METHODS: We reported the case of a 9-year-old Chinese girl who presented with abnormal low oxygen saturation values on pulse oximetry and no oximetry results were obtained during blood gas analysis (BGA).

RESULTS: High-performance liquid chromatography (HPLC) and capillary electrophoresis demonstrated that the presence of a low oxygen affinity hemoglobin variant, characterized as hemoglobin Titusville, was proven by gene sequencing. The patient's mother and aunt also carry the hemoglobin variant, representing the first Chinese family case reported.

CONCLUSIONS: Hemoglobin Titusville is a rare genetic hemoglobin structural defect. early diagnosis can help patients and clinicians avoid unnecessary anxiety and costly or excessive clinical investigations.