Krüppel-like factor 1 (KLF1) gene single nucleotide polymorphisms in sickle cell disease and its association with disease-related morbidities.

Abstract

Sickle cell disease has varied clinical symptoms, and patients having high fetal hemoglobin (HbF) have milder symptoms. Various genetic factors are known to modulate the HbF levels. Krüppel-like factor 1 (KLF1) is a transcription factor that regulates the beta-like globin gene expression. Any variation in KLF1 gene may alter the sickle cell disease phenotype. Xmn-I polymorphism is also known to regulate the gamma globin gene expression. Present studies were carried out to investigate the effect of KLF1 gene mutations and Xmn-I polymorphism on the sickle cell disease severity and to ascertain the genotype-phenotype correlation. One hundred and eighteen sickle cell disease patients having a median follow-up of 5years (3-10years) were recruited. Clinical details were recorded from their retrospective medical records. Xmn-I polymorphism were analyzed using PCR-RFLP method. Variations in KLF1 gene were identified using Sanger sequencing. Out of 118 patients, 24 had acute chest syndrome and 21 patients had more than 2 pain episodes per year. There were no significant differences in sickle cell disease-related morbidities in male and females barring leg ulcers. A total of 6 polymorphism were observed in KLF1 gene, out of which 3 are novel (c.-304G > C, c.*141A > G and c.*178A > G). No statistically significant association of any of SNPs identified in KLF1 gene or Xmn-I polymorphism was seen with HbF levels as well as the sickle cell disease-related morbidities. No association exists between fetal hemoglobin or sickle cell disease-related morbidities and Xmn-I polymorphism or with SNPs identified in KLF1 gene in the studied cohort.