OBJECTIVE: To analyze the correlation between variants in the start codon of the α-globin gene and phenotypes of thalassemia, so as to provide a basis for the diagnosis and prevention of α-thalassemia. METHODS: A retrospective study was conducted on 7 patients diagnosed by Yangjiang People's Hospital and Guangzhou Hybribio Co. Ltd., from June 2019 to October 2022. Routine blood tests and hemoglobin electrophoresis were carried out. Potential variants were identified through polymerase chain reaction (PCR) combined with Reverse dot blotting (RDB), Gap-PCR, and Sanger sequencing. This study has been approved by the Medical Ethics Committee of People's Hospital of Yangjiang (Ethics No: 20240001). RESULTS: For the 7 patients, results of blood routine test of one case was unknown, and that of another was normal. The remaining 5 cases had presented with microcytic hypochromic anemia. The results of hemoglobin electrophoresis showed that one case had normal Hb A and slightly lower Hb A2, whilst another had significantly decreased Hb A and Hb A2, in addition with the appearance of a Hb H band. The content of Hb Bart's in four neonates was ≥ 0.4%. The remaining one case had no result. Genetic testing has identified 4 rare start codon mutations, namely HBA2: c.2delT, HBA2: c.1A>G, HBA2: c.1A>T, and HBA1: c.2T>C. Among these, Patient 1 had harbored compound heterozygous variants of HBA2: c.427T>C (Hb CS) and HBA2: c.2delT. Patient 4 had harbored compound heterozygous variants of HBA2: c.1A>G and Southeast Asian type deletion. CONCLUSION Heterozygotes with HBA start codon variants usually present as silent or mild thalassemia, and the symptoms of anemia may deteriorate when combined with other α-thalassemia variant. The HBA2: c.1A>T start codon variant was unreported previously in China. The detection of start codon variants has helped to clarify the causes of anemia, genetic counseling, and guidance for reproduction.
Humans ; Phenotype ; Codon, Initiator/genetics* ; Female ; Male ; Retrospective Studies ; alpha-Globins/genetics* ; alpha-Thalassemia/genetics* ; Hemoglobin A/genetics* ; Adult ; Mutation

Objective:To explore the hematological phenotype and genotypic characteristics of five Chinese individuals with a rare thalassemia mutation HBB: c. 93-21G>A. Methods:A retrospective study was carried out on five individuals identified by the People′s Hospital of Yangjiang and Guangzhou Hybribio Co., Ltd. from May 2018 to September 2022. Routine blood test and hemoglobin electrophoresis were performed, and the genotypes of five subjects were determined by using PCR combined with reverse dot blotting (RDB), nested PCR, Gap-PCR and Sanger sequencing. This study was approved by Medical Ethics Cornmittee of the People′s Hospital of Yangjiang (Ethics No. 20240001).Results:Among the five individuals, hematological data of one was unavailable, and the remaining four had presented with microcytosis and hypochromia. The results of hemoglobin electrophoresis indicated that all of them had a HbA 2 level of ≥4.7%. Genetic analysis showed that one case had harbored compound heterozygous mutations of ααα anti3.7 triplet and HBB: c. 93-21G>A, one had compound heterozygous mutations of -α 3.7 and HBB: c. 93-21G>A, whilst the remaining three were heterozygous for the HBB: c. 93-21G>A mutation. Conclusion:The hematological phenotype of β-thalassemia carriers ( HBB: c. 93-21G>A) is similar to that of other β + thalassemia heterozygotes with mild β-thalassemia characteristics.

Objective: To investigate the role of lysosomes in manganese-induced toxicity in human neuroblastoma SK-N-SH cells. Methods: SK-N-SH cells were treated with MnCl₂ at doses of 0.062 5, 0.125, 0.25, 0.5, 1.0, 2.0 and 4.0 mmol/L for 24 h, and the cell viability was detected by MTT assay. Cells were treated with MnCl₂ at doses of 0.125, 0.25, 0.5 and 1.0mmol/L for 24 h, and lysosomes labeled with lysotracker red were observed by laser confocal microscopy, the expression levels of LAMP1 and CTSD were detected by western blot, and CTSD activity was detected by Cathepsin D Activity Fluorometric Assay Kit. Results: Compared with the control group, the survival rates of SK-N-SH cells were decreased significantly in the 0.5-4.0 mmol/L MnCl₂ treatment groups (P<0.01) , the relative fluorescence intensities of 0.5 and 1.0 mmol/L MnCl₂ treatment groups were increased (P<0.01) . Compared with the control group, the 0.125-0.5 mmol/L MnCl₂ treatment groups had significant increase in the the expression of LAMP1 (P<0.01) . Compared with the control group, the expression of m-CTSD was significantly increased at the does of 0.125-0.25 mmol/L MnCl₂, while it was decreased at the does of 1.0 mmol/L (P<0.01) . Otherwise, it wasn’t observed significant difference of the activity of CTSD between different MnCl₂ treatment groups. Conclusion MnCl₂ could cause cytotoxicity in SK-N-SH cells. Lysosomes may play a normal function at low doses of manganese, but they may be damaged at high doses of manganese. As an organelle that can degradate substrates in autophagy, lysosomes participate in the neurotoxic mechanism of manganese.