Identification of the Rare, Four Repeat Allele of IL-4 Intron-3 VNTR Polymorphism in Indian Populations.

BACKGROUND: Cytokines are cell signaling molecules which upon release by cells facilitate the recruitment of immune-modulatory cells towards the sites of inflammation. Genetic variations in cytokine genes are shown to regulate their production and affect the risk of infectious as well as autoimmune diseases. Intron-3 of interleukin-4 gene (IL-4) harbors 70-bp variable number of tandem repeats (VNTR) that may alter the expression level of IL-4 gene. OBJECTIVE: To determine the distribution of IL-4 70-bp VNTR polymorphism in seven genetically heterogeneous populations of Chhattisgarh, India and their comparison with the finding of other Indian and world populations. METHODS: A total of 371 healthy unrelated individuals from 5 caste and 2 tribal populations were included in the present study. The IL-4 70-bp VNTR genotyping was carried out using PCR and electrophoresis. RESULTS: Overall, 3 alleles of IL-4 70-bp VNTR (a2, a3 and a4) were detected. The results demonstrated the variability of the IL-4 70-bp VNTR polymorphism in Chhattisgarh populations. Allele a3 was the most common allele at the 70-bp VNTR locus in all populations followed by a2 allele. This study reports the presence four repeat allele a4 at a low frequency in the majority of the Chhattisgarh populations studied. Further, the frequency of the minor allele (a2) in Chhattisgarh populations showed similarity with the frequencies of European populations but not with the East Asian populations where the a2 allele is a major allele. CONCLUSIONS: Our study provides a baseline for future research into the role of the IL-4 locus in diseases linked to inflammation in Indian populations.

Neonatal screening of sickle cell anemia: a preliminary report.

OBJECTIVE: To evaluate feasibility of systematic neonatal screening for sickle cell disease in Chhattisgarh. METHODS: A pilot study was done from February 2008 through January 2009 in Department of Pediatrics & Neonatology, Pt. J.N.M. Medical College & Dr.B.R.A.M. Hospital, Raipur (Chhattisgarh) on a total of 1,158 neonates. Blood samples from the neonates were taken after 48 h of birth on filter paper for detection of sickle cell anemia using Biorad hemoglobin variant Neonatal sickle cell short programme by high performance liquid chromatography (HPLC). On follow up, cases were analyzed by HPLC using Beta thalassemia short program to rule out false negative case and other hemoglobin variants. RESULTS: Of the 1,158 neonates screened, 628 were boys (54.2%) and 530 were girls (45.8%). Sickle cell disease was found in 3 cases (0.2%) (95%C.I 0.12-0.28), sickle cell trait was found in 68 cases (5.8%) (95%C.I 4.5-7.5). After 6-9 mo of age three cases of sickle cell diseases were reinvestigated, out of which one case turned out to be double heterozygous for sickle cell and beta thalassemia trait. Fourteen preterm neonates reported as normal in initial screening were called for follow up after 6 mo of age, 10 infants reported in OPD and 4 lost in follow up. These 10 infants were reinvestigated; 2 had sickle cell disease, 1 had sickle cell trait and 7 infants were normal. Sixty eight cases of sickle cell trait found with initial screening were also called for follow up after 6 mo of age; 61 cases reported in OPD between 6 mo to 1 y of age and 7 cases lost in follow up. Sixty one infants were reinvestigated; 60 had sickle cell trait and 1 had sickle cell disease which was reported earlier as Sickle cell trait (FAS). Thus on total follow up of cases, there were 5(0.4%) sickle cell disease, 61(5.26%) sickle cell trait, 1(0.08%) double heterozygous for sickle cell and beta thalassemia trait which needs mutation studies for thalassemia characterization (s/ß(0) or s/ß(+)). CONCLUSIONS: Early detection of sickle cell disease (SS) done by neonatal screening will help in early prevention and management of complications in postnatal period.