Hepcidin gene polymorphisms and iron overload in ß-thalassemia major patients refractory to iron chelating therapy.

BACKGROUND: ß Thalassemia is one of the most common groups of hereditary haemoglobinopathies. Affected people with thalassemia major are dependent on regular blood transfusion which on the long term leads to iron overload. Hepcidin is a peptide hormone and an important regulator of iron homeostasis, especially in thalassemia. Expression of this hormone is influenced by polymorphisms within the hepcidin gene, HAMP. Several studies emphasized the role of single nucleotide polymorphisms (SNPs) located in the promoter region of the gene. This study aimed to analyze the association between three SNPs in promoter of HAMP, c.-582A > G, c.-443C > T, and c.-153C > T, with iron overload in ß-thalassemia major patients. METHODS: A total of 102 samples from ß thalassemia major patients were collected. Genomic DNA was extracted and segments of DNA encompassing rs10421768 and rs142126068 were sequenced. Statistical analysis was performed by SPSS Statistics 23 using independent t test and Fisher's exact test. RESULTS: A total of 102 adult ß-thalassemia major patients were genotyped for three SNPs in the promoter region of HAMP gene by PCR and direct sequencing. Most of the patients (71.3%) were iron overloaded (based on plasma ferritin > 1000 ng/ml) in spite of receiving regular iron-chelating therapy. Our analysis revealed a statistically significant difference between the level of cardiac iron accumulation and c.-582A > G variant (p = 0.02). For c.-443C > T statistical analysis was on the edge of the significant relationship between the minor allele and serum ferritin (p = 0.058). All samples were homozygous for allele C of c.-153C > T. CONCLUSIONS: Despite chelating therapy, iron overload is still one of the main complications of thalassemia. Our findings and others emphasize the role of hepcidin -582A > G polymorphism as a key component of iron homeostasis in these patients.

Clinical genome editing to treat sickle cell disease-A brief update.

Sickle cell disease (SCD) is one of the most common hemoglobinopathies. Due to its high prevalence, with about 20 million affected individuals worldwide, the development of novel effective treatments is highly warranted. While transplantation of allogeneic hematopoietic stem cells (HSC) is the standard curative treatment approach, a variety of gene transfer and genome editing strategies have demonstrated their potential to provide a prospective cure for SCD patients. Several stratagems employing CRISPR-Cas nucleases or base editors aim at reactivation of γ-globin expression to replace the faulty ß-globin chain. The fetal hemoglobin (HbF), consisting of two α-globin and two γ-globin chains, can compensate for defective adult hemoglobin (HbA) and reverse the sickling of hemoglobin-S (HbS). Both disruption of cis-regulatory elements that are involved in inhibiting γ-globin expression, such as BCL11A or LRF binding sites in the γ-globin gene promoters (HBG1/2), or the lineage-specific disruption of BCL11A to reduce its expression in human erythroblasts, have been demonstrated to reestablish HbF expression. Alternatively, the point mutation in the HBB gene has been corrected using homology-directed repair (HDR)-based methodologies. In general, genome editing has shown promising results not only in preclinical animal models but also in clinical trials, both in terms of efficacy and safety. This review provides a brief update on the recent clinical advances in the genome editing space to offer cure for SCD patients, discusses open questions with regard to off-target effects induced by the employed genome editors, and gives an outlook of forthcoming developments.

An Easy Multiplex PCR-SSP Assay for the Genotyping of KEL1 and KEL2 in Multi-transfused Patients.

Kell blood group system consists of 34 antigens. KEL1 and KEL2 are the most clinically important antigens of this system, causing hemolytic disease of the fetus and newborn (HDFN) and transfusion reaction. A total of 200 samples from blood donors were tested serologically for the presence of KEL1 and KEL2 antigens on erythrocytes. Genomic DNA was analyzed by PCR-SSP method to determine the Kell genotype. A multiplex PCR-SSP assay was designed and tested to genotype KEL1/KEL2 alleles in a single reaction. PCR genotyping revealed samples as; KEL2/KEL2 (93.5%) and KEL1/KEL2 (6.5%), while no sample determined as KEL1/KEL1. A 100% concordance observed between PCR and serological results. Multiplex PCR accurately diagnosed Kell genotype. Kell blood group genotyping by PCR-SSP can be used as an alternative method, especially in multi-transfused patients where serological findings are ambiguous.