rs11886868 and rs4671393 of BCL11A associated with HbF level variation and modulate clinical events among sickle cell anemia patients

Figures & data

Table 1 Hematological, demographic, and clinical data of studied population

	SS patients with HbF < 15%	SS patients with HbF > 15%	P
Age (mean)	27 ± 2.9	31 ± 3.6	0.425
Sex ratio (M/F)	39/37	37/35	0.423
Hb (g/dl)	7.3 ± 0.9	10 ± 0.6	0.046
RBC (1012/l)	2.89 ± 1.02	3.69 ± 1.2	0.425
MCV (fl)	77.2 ± 1.3	80 ± 2.7	0.059
MCH (pg)	35.7 ± 1.02	37 ± 2	0.132
RDW (%)	5.29 ± 1.02	5.69 ± 0.1	0.690
HbA	0	0	1
HbS (%)	86.4 ± 0.4	76 ± 0.1	0.05
HbF (%)	10.6 ± 4.3	22 ± 7.3	0.045
HbA2	3 ± 0.1	2.7 ± 0.3	0.725

SS: homozygous of beta-globin gene mutation.

The demographic and hematological values are indicated as mean ± standard deviation.

Hb, hemoglobin; RBC, red blood cell; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; RDW, red blood distribution width.

Statistics for the comparison of demographic and hematological variables between the two groups were performed using the t-test and chi-square test as appropriate (SPSS 16.0).

Table 2 Distribution of genotypes and allele frequency of polymorphisms studied according to the HbF level in SCA patients

BCL11A gene	SCA patients with HbF < 15%	SCA patients with HbF > 15%	P	RR CI 95%
Rs 11886868
CC	0	14	1*	–
CT	46	14	0.029	0.08 (0.002–0.885)
TT	28	28	1	–
C	0.42	0.62	1*	–
T	0.70	0.58	0.06	0.39 (0.178–0.853)
Rs4671393
AA	0	22	1*	–
AG	28	20	0.016	0.0176 (0.03–1.15)
GG	46	32	0.021	0.189 (0.03–1.22)
A	0.187	0.396	1*	–
G	0.812	0.566	8.9 × 10^−3	0.567 (0.35–0.93)
Combined genotype
GG/CT	46	14	0.01	0.59 (0.188–0.951)
AG/CT	28	14	0.05	0.89 (0.176–0.853)

1*, reference group; P, index of significance; RR, relative risk; CI, interval of confidence.

Table 3 The relationships between genotypes found and clinical events determined using logistic regression

BCL11A gene	VOC	Stroke	Osteonecrosis	Cholelithiasis	P
rs11886868
CC	0	0	0	0	1*
CT	46	10	40	36	0.009
TT	28	6	20	15	0.011
rs4671393
AA	0	0	0	0	1*
AG	28	8	20	18	0.016
GG	46	6	36	30	0.021
Combined genotype
GG/CT	46	6	36	30	8.2 × 10^−3
AG/CT	28	8	20	18	0.04

VOC, vaso-occlusive crisis; 1*, reference group; P, index of significance. The first P-value is calculated to determine any associations between the genotypes and complications. The second one is calculated to determine any association between the combined genotype and the complications.