Genetic association study of selected candidate genes (ApoB, LPL, Leptin) and telomere length in obese and hypertensive individuals

Abstract

Background: A genetic study was carried out among obese and hypertensive individuals from India to assess allelic association, if any, at three candidate loci: Apolipoprotein B (ApoB) minisatellite and two tetranucleotide repeat loci; LPL (Lipoprotein lipase) and Leptin. Attempt has also been made to find out whether telomere length attrition is associated with hypertension and obese individuals.

Leptin Gene Tetranucleotide Repeat Polymorphism in Obese Individuals in Egypt

“…The predominant genotype was 152/152 in obese subjects with a frequency of 0.114 compared to the genotype 152/156 in normal subjects with a frequency of 0.135. (41) Agreeing with our results, they have found that in obese individuals, the frequency of genotype II/II was significantly higher as compared to normal and hypertensive individuals, genotype I/II had a significantly higher frequency in obese group as well compared to normal and hypertensive group. (41) In another study done by Moffett et al, among African American subjects, they reported a wide heterogeneity of the leptin gene tetranucleotide repeat alleles being classified into three classes; type 1 alleles (146-178 bp); type 2 alleles (165 and 193 bp) and type 3 alleles (210 and 254 bp).…”

“…(41) Agreeing with our results, they have found that in obese individuals, the frequency of genotype II/II was significantly higher as compared to normal and hypertensive individuals, genotype I/II had a significantly higher frequency in obese group as well compared to normal and hypertensive group. (41) In another study done by Moffett et al, among African American subjects, they reported a wide heterogeneity of the leptin gene tetranucleotide repeat alleles being classified into three classes; type 1 alleles (146-178 bp); type 2 alleles (165 and 193 bp) and type 3 alleles (210 and 254 bp). They attributed the failure of some population-based studies to detect association between measures of obesity and the leptin gene-(TTTC) locus to be due to this wide heterogeneity.…”

“…Similarly, the 154 bp allele was found to be the most frequent one among normal subjects from Madagascar (31%), Russia (36%), Great Britain (36%), Central Africa (29%), West Africa (35%), Euro Americans (19%) and in African Americans (29%). (31)(32)(33)(34)(35)(36)(37)(38)(39)(40) A nearly similar size alleles were also reported among normal Indians including the 152 bp and 156 bp alleles (24% each), (41) while in Malaysia it was the 157 bp allele (16%). (31) On the other hand, a bigger size allele (162 bp) was found to be the most frequent one among Costa Ricans (23%).…”

“…The mean age (±SD) and gender frequency in cases were non-significantly different from that of the controls, whereas the mean values (±SD) of weight, BMI, WHR, serum levels of TC, TG, HDL-C and LDL-C were significantly higher in cases of obesity than in controls (p <0.001 for each). Allelic analysis of the leptin gene polymorphism showed that 13 different alleles were identified in all cases of obesity (11 alleles in MS cases and 12 in cases of simple obesity) versus only 5 alleles in normal controls ( (39)(40)(41)31) , using the cluster multivariate analysis showed that the frequency of the Class I/Class II alleles in our sample (Egyptians n=83) was very near to African and Mediterranean countries but somewhat different from Asian and European countries ( Figure 1). …”

“…Interestingly, the number of alleles found in normal subjects differed too much in different populations with different ethnicities. For instance, it was 13 alleles in Indians, (41) 11 alleles in Costa Ricans, (39) 22 alleles in normal subjects from Madagascar, 11 in Russians and British, 18 in normal subjects from Hong Kong, 12 in Taiwanese, 12 in Malaysians, 14 in Central Africans, 17 in West Africans, (31) 14 alleles in normal Euro Americans, 9 alleles in Samoans and 19 alleles in African Americans. (40) In our study, the most frequent allele found among normal Egyptians was the 154 bp allele (92.2%).…”