Associations of α-thalassemia and BCL11A with stroke in Nigerian, United States, and United Kingdom sickle cell anemia cohorts.

Insight of fetal to adult hemoglobin switch: Genetic modulators and therapeutic targets.

Development and Validation of a Pediatric Severity Index for Sickle Cell Patients.

Sickle cell disease (SCD) poses considerable public health problems in India. This study was undertaken to understand the clinical course of SCD among children identified during newborn screening programmes in Gujarat and Madhya Pradesh where the frequency of the HbS gene is high. A total of 8,916 newborn babies 8,411 from Gujarat and 505 from Madhya Pradesh were screened over 6 years (2010–2016) using HPLC and the diagnosis was confirmed by molecular analysis in a subset. A total of 128 babies (122 Gujarat, 6 Madhya Pradesh) were identified with sickle cell disease, of whom 87 (69 HbSS, 18 HbS-β thalassemia) from Gujarat were followed for 0.5–6.6 years. Acute painful events, severe anemia and fever with infections were the major complications and 23 babies required hospitalization. Severe to moderate clinical presentation was found in 13.8% babies with SCD whereas, 86.2% babies had a milder presentation. Presence of ameliorating factors (α-thalassemia and Xmn 1 polymorphism) did not have a discernible effect on the clinical severity. Parents of babies with SCD were educated and counseled for home care. Distribution of mobile phones to 44 families having babies with SCD was beneficial as it allowed regular contact with patients and their families. Genetic counseling to the affected families has increased the awareness and acceptance for prenatal diagnosis and 18 couples opted for prenatal diagnosis in subsequent pregnancies. SCD is not always mild among tribal groups in India. Therefore, facilities for early diagnosis and prophylactic treatment in the tertiary care centers should be made available. The difficulties in regular follow up of the babies in remote rural areas have also been highlighted.

Newborn Screening for Sickle Cell Disease Among Tribal Populations in the States of Gujarat and Madhya Pradesh in India: Evaluation and Outcome Over 6 Years

.............................................................................................................................. v Chapter 1: Introduction, Background, and Significance .................................................. 1 The RNA exosome ............................................................................................................ 2 The Ski complex is a cofactor of the exosome required for cytoplasmic 3’-5’ RNA decay .. 4 Ski7 coordinates the exosome and Ski complex during normal and nonstop mRNA decay .......................................................................................................................................... 5 HBS1 is the paralog of SKI7 and is also involved in RNA quality control............................ 9 Gene duplication and proteomic diversity ........................................................................ 14 Experimental analysis can distinguish between subfunctionalization and neofunctionalization ......................................................................................................... 16 Alternative splicing in fungi and its role in proteomic diversity .......................................... 19 Significance ..................................................................................................................... 22 Chapter 2: Materials and Methods ................................................................................... 24 Strains and Media ............................................................................................................ 25 Plasmids .......................................................................................................................... 25 RNA isolation ................................................................................................................... 26 PCR and rt-PCR .............................................................................................................. 26

Evolution via gene duplication and alternative splicing in the eukaryotic ski7 and hbs1 genes

Dear Editor, Sickle cell anaemia (SCA) is a monogenic disorder (β6-GAG>GTG) with exceptional phenotypic variability. In India, SCA is prevalent amongst tribal and some non-tribal populations [1]. Foetal haemoglobin (HbF) is one of the most established genetic modulators for the severity of sickle cell disease [2]. Genome-wide association studies (GWAS) have located three quantitative trait loci (QTL) harbouring single nucleotide polymorphisms (SNPs) with strong association with Hb F level in SCA patients [3]. These QTLs include chromosome 11-XmnI Gγ, chromosome 6q23-HBS1L-MYB and chromosome 2p-16-BCL11A. Amongst them, the XmnI polymorphism is the most widely studied SNP in diverse populations. Together, these SNPs accounted for >20 % of variation in two independent SCA cohorts—the African American and the Brazilian cohort [3]. However, the effect of these polymorphisms on the HbF levels and on disease severity has not been studied in Indian patients. We analysed 3 SNPs in the intronic region of the BCL11A gene and 5 SNPs in the HBS1L-MYB gene in 46 paediatric SCA patients (age >4 years) identified by neonatal screening in relation to the HbF levels and disease severity. Out of 46 patients, 18 were females and 28 were males. The HbF levels were measured at their last follow-up (average age 4 years) by high-performance liquid chromatography (HPLC) on the VARIANTTM Hemoglobin Testing System (Bio-Rad Laboratories, Hercules, CA, USA). None of the patients were on hydroxyurea. The patients were divided into mild (25) and severe (21) based on a paediatric scoring system [4–6], depending on the number of hospitalizations, dactylitis, blood transfusions, painful crisis, sepsis, sequestration crisis and cerebral infarcts. The babies with sepsis and stroke were considered to be severe. The study was approved by the Institutional Ethical Committee (IEC). An informed consent was obtained from all the parents. The sickle genotype was confirmed by DNA analysis and alpha genotyping, and XmnI polymorphism was studied. The 3 SNPs in the BCL11A gene (rs4671393, rs11886868 and rs7557939) and the 5 SNPs in the HBS1L-MYB gene (rs4895441, rs28384513, rs7776054, rs9399137 and rs9389268) were studied by DNA sequencing. The A allele of the SNP rs4671393 in the BCL11A gene showed a statistically significant association with the milder cases with the allele frequency of 0.24 as compared to 0.09 in the severe patients with the odds ratio (OR) of 3.19 (95 % C.I. 1.40–7.28) (p= 0.005) (Table 1). The AA genotype of rs4671393 also showed the highest mean percentage of HbF levels (29.0 ± 1.0 %) in comparison to the AG (22.0 ± 9.1 %) and GG genotypes (22.0 ± 7.9 %). The other 2 SNPs, rs11886868 and rs7557939, of the BCL11A gene did not show significant association with the milder and severe SCA cases (Table 1). In the HBS1L-MYB intergenic region, the SNP rs9389268 showed a statistically significant association with milder disease with the G allele frequency of 0.14 in the milder cases and 0.03 in the severe cases with the OR of 5.26 (95 % C.I. 1.46–18.9) (Table 1). The GG genotype of rs9389268 also showed high HbF levels of 29.1 ± 12.3 % as compared to the AA genotype (22.8 * Roshan Colah colahrb@gmail.com

Yogesh Trivedi

Papers

Influence of single nucleotide polymorphisms in the BCL11A and HBS1L-MYB gene on the HbF levels and clinical severity of sickle cell anaemia patients