BACKGROUND: Sickle cell anemia (SCA) is an inherited blood disorder. SCA 
patients present clinical and hematologic variability that cannot be only 
explained by the single mutation in the beta-globin gene. Others genetic 
modifiers and environmental effects are important for the clinical phenotype. 
SCA patients present arginine deficiency that contributes to a lower nitric 
oxide (NO) bioactivity.
OBJECTIVE: The aim of this work is to determine the association between 
hematological and biochemical parameters and genetic variants from eNOS gene, in 
pediatric SCA patients.
METHODS: 26 pediatric SCA patients were genotyped using polymerase chain 
reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques in 
three important eNOS gene polymorphisms - rs2070744, rs1799983 and intron 4 
VNTR.
RESULTS: Results from this study show a significant statistical association 
between some parameters and genetic variants: an increased reticulocyte count 
and high serum lactate dehydrogenase levels were associated with both the 
rs2070744_TT and the rs1799983_GG genotypes at eNOS gene and high levels of 
neutrophils were associated with the eNOS4a allele at intron 4 VNTR.
CONCLUSIONS: Our results reinforce the importance of NO bioactivity in SCA. We 
presume that NO, and its precursors might be used as therapy to improve the 
quality of life of SCA patients.