Molecular characterization of HAMP rs10421768 gene and phenotypic expression of hepcidin; a case-control study among sickle cell anaemia patients in Ghana

by Samuel Kwasi Appiah, Charles Nkansah, Gabriel Abbam, Felix Osei-Boakye, Kofi Mensah, Simon Bannison Bani, Solomon Chemogo, Lydia Sarpong, Takyi Godfred Addae, Daniel Boamah Sefa, Richard Adu Croffien, Larry Adom, Rekhiatu Oboirien Abdul Rauf, Farrid Boadu, Godfred Appiah Amoah, Ejike Felix Chukwurah

Background

The sporadic nature of blood transfusion therapy coupled with the alteration of HAMP genes may exacerbate the risk of iron burden in sickle cell anaemia (SCA) patients. The study determined the polymorphic distribution of the HAMP promoter gene rs10421768 and hepcidin levels in SCA patients.

Method

Sixty participants aged ≥12years [45 SCA patients and 15 controls (HbA)] were recruited from 15^th March, 2023 to 20^th July, 2023 for a case-control study at Methodist Hospital Wenchi, Ghana. Complete blood count and hepcidin levels assessment were done using haematology analyzer and ELISA, respectively. Genomic DNA was extracted using the Qiagen Kit, and HAMP gene rs10421768 (c.-582 A>G) was sequenced using the MassARRAY method. Data were analysed using SPSS version 26.0.

Results

The frequencies of the HAMP promoter rs10421768 genotypes AA, AG, and GG were 64.4%, 33.3%, and 2.2% in SCA patients, and 86.7%, 13.3%, and 0% in the controls, respectively. Serum hepcidin levels were significantly higher among controls than cases [204.0 (154.1–219.3) vs 150.2 (108.1–195.6)μg/L, p<0.010]. Participants with HAMP rs10421768 homozygous A genotype had higher serum levels of hepcidin compared with those in the wild genotypes (AG/GG) group [(188.7 (130.9–226.9) vs 136.8 (109.7–157.8)μg/L, p<0.016]. Disease severity and blood cell parameters were not associated with the HAMP variants (p>0.05).

Conclusion

The HAMP promoter rs10421768 AA genotype has the highest frequency of distribution and the GG genotype with the least distribution. Participants with HAMP rs10421768 G allele (c.-582A>G) had reduced levels of hepcidin. HAMP rs10421768 genotypes had no association with blood cell parameters and disease severity. The HAMP rs10421768 genotypes may influence serum levels of hepcidin. Further study is required to elucidate the potential effect of the G allele on hepcidin transcription.