Glutathione S-transferase gene polymorphism: Relation to cardiac iron overload in Egyptian patients with Beta Thalassemia Major.
OBJECTIVE
Estimating the prevalence of glutathione S-transferase gene polymorphism (GSTM1) null genotype among patients with beta thalassemia major (β-TM) in relation to myocardial status assessed by tissue Doppler and cardiac siderosis assessed by cardiac magnetic resonance imaging (MRI) T2*.


METHODS
Hundred patients with β-TM and 100 healthy controls were enrolled. Complete blood count (CBC), mean serum ferritin and GSTM1 genotyping, echocardiography, tissue Doppler, and cardiac MRI T2* were done.


RESULTS
Serum ferritin ranged from 1200 to 8000 ng/ml, and mean T2* value was 27.10 ± 11.20 ms. Of patients, 68 (68%) had no cardiac siderosis, while 24 (24%) with mild to moderate, and 8 (8%) with sever cardiac siderosis. T2* values were not correlated with serum ferritin (r = -0.09, P = 0.50). GSTM1 null genotype was prevalent in 46% of patients and 40% of controls (P = 0.69). Patients with null genotype had significantly shorter T2* (P = 0.001), higher left ventricular end-diastolic diameter (P = 0.002), and shorter ejection time (P = 0.005) with no significant relation to serum ferritin (P = 0.122). GSTM1 null genotype was the only predictor for cardiac iron overload (P = 0.002).


CONCLUSIONS
Serum ferritin concentrations have been shown to correlate poorly with all stages of cardiac dysfunction. Low cardiac MRI T2* values occur in patients with β-TM despite good chelation therapy, suggesting a possible role of genetic factors in cardiac siderosis.


CONCLUSIONS
GSTM1 null genotype is significantly associated with cardiac iron overload independent of serum ferritin in Egyptian patients with β-TM.
Galila M
GM
Mokhtar
Eman M
EM
Sherif
Nevin M
NM
Habeeb
Abeer A
AA
Abdelmaksoud
Eman A
EA
El-Ghoroury
Ahmed S
AS
Ibrahim
Enas M
EM
Hamed
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D004534:Egypt; D005260:Female; D005293:Ferritins / Q000097:blood / Q000235:genetics; D015870:Gene Expression; D005838:Genotype; D005982:Glutathione Transferase / Q000172:deficiency / Q000235:genetics*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D019190:Iron Overload / Q000209:etiology / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D011110:Polymorphism, Genetic; D012720:Severity of Illness Index; D012806:Siderosis / Q000209:etiology / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D065227:Transfusion Reaction; D017086:beta-Thalassemia / Q000235:genetics / Q000473:pathology / Q000628:therapy*
D005293:Ferritins; D005982:Glutathione Transferase; D007501:Iron
Beta thalassemia major; Cardiac T2*; Glutathione S-transferase