Does the geographical gradient of ApoE4 allele exist in China? A systemic comparison among multiple Chinese populations.

The allelic frequencies of apolipoprotein E (apoE) vary substantially around the world. There is a conspicuous south-to-north gradient of e4 frequencies in Europe, with the proportion of e4 carriers from only 10-15% in the south to 40-50% in the north. The mechanism may be related to the possibility that e4 carriers are less likely to develop vitamin D deficiency. In addition, Asian populations traditionally have lower e4 frequency than Europeans, which may be attributed in part to the scarce or irregular food supplies in Western world in the recent past. However, whether these geographical distribution gradients exist in China is yet unknown. ApoE genotypes of 200 children from Nanning City were determined by PCR-restriction fragment length polymorphism (RFLP) analysis. Allele frequency data of 18 other populations were collected from published sources and correlated with latitude and longitude information from different geographic resources. In our subjects, the frequencies of apoE genotypes were E3/E3: 73.0%, E3/E2: 15.0%, E4/E3: 5.0%, E4/E4: 5.0%, and E4/E2: 2.0%; the frequencies of apoE alleles were e2: 8.5%, e3: 83.0%, and e4: 8.5%, respectively. The total sample consisted of 3,679 individuals from 19 Chinese populations; the allelic frequencies were e2: 7.6%, e3: 85.5%, and e4: 6.9%, respectively; the proportion of e4 carriers was from 4.9% in Kunming to 17.5% in Harbin. Systemic comparison among multiple Chinese populations revealed that positive correlation existed between the e4 allele frequency distribution and latitude north (r=0.586, P=0.008), but no correlation of the e4 allele frequency distribution with longitude east was found (r=-0.018, P=0.942). We conclude that there is a south-to-north, but not an east-to-west gradient for the apoE4 allele in China.

[Relationship between gene polymorphisms in MMP-9 and Helicobacter pylori-related upper gastrointestinal disease in children].

OBJECTIVE: To investigate the relationship of the promoter of matrix metalloproteinase-9 (MMP-9) gene polymorphisms with the susceptibility and clinical features of Helicobacter pylori (H. pylori)-related chronic gastritis and duodenal ulcer in children. METHODS: One hundred children with chronic gastritis, 32 children with duodenal ulcer and 102 healthy children were enrolled.The promoter of MMP-9-1562C/T gene polymorphisms were genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and sequencing. MMP-9 mRNA expression in gastric mucosa was confirmed by reverse transcription polymerase chain reaction. RESULTS: The genotype distributions and allele frequencies of MMP-9-1562C/T gene polymorphisms were similar in gastric upper gastrointestinal disease and healthy subjects. The relative risk for H.pylori infection in C/C genetype carriers was 3.1 times as high as that in T allele (C/T+T/T) carriers in children with chronic gastritis. MMP-9-1562 C/T gene polymorphisms did not affect MMP-9 mRNA expression level. CONCLUSIONS: These data suggest that MMP-9-1562 C/T gene polymorphisms are not associated with susceptibility to chronic gastritis and duodenal ulcer in children. The C/C genotype of MMP-9-1562 C/T gene polymorphism might be associated with H.pylori infection.

Genetic variation of apolipoprotein E does not contribute to the lipid abnormalities secondary to childhood minimal change nephrotic syndrome.

Minimal change nephrotic syndrome (MCNS) is a common progressive renal disorder occurring in childhood that is characterized by alterations of permselectivity at the glomerular capillary wall, resulting in its inability to restrict the urinary loss of protein. Hyperlipidemia (HLP) is not only an important clinical manifestation of MCNS but is also involved in cardiovascular disease and in progressive renal damage. ApoE is a polymorphic protein. Besides modulation of lipid metabolism, apoE can also elevate the sulfate-proteoglycan in glomerular filtration membrane and inhibit the proliferation of mesengial cells. The present study aimed mainly to determine whether genetic polymorphism of apoE is involved in the HLP secondary to childhood MCNS. Genomic DNA was extracted from 250 children diagnosed with MCNS and 200 healthy controls. ApoE genotype was determined by PCR-restriction fragment length polymorphism (RFLP) analysis. The fasting serum lipoprotein (a) [Lp(a)], total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (apoA1), and apoB were measured. Serum concentrations of Lp(a), TC, TG, HDL-C, nonHDL-C, LDL-C, and apoB were higher in the MCNS than in the control group (P < 0.05). No significant differences in genotypes and alleles frequencies were observed for the apoE Hha I restriction sites in MCNS patients as compared to controls (P > 0.05). No significant differences in serum lipid levels were observed for variant genotypes and alleles of apoE Hha I restriction site in both MCNS and healthy children (P > 0.05). Genetic variation of apoE does not contribute to the lipid abnormalities secondary to childhood MCNS.

Effect of apolipoprotein B polymorphism on body mass index, serum protein and lipid profiles in children of Guangxi, China.

BACKGROUND: Some studies have demonstrated that genetic variance of apolipoprotein B (APOB) plays an important role in lipid metabolism in childhood. However, little information exists about the distribution and effect of the APOB polymorphism among the population from Guangxi, where populations have developed through complex interaction among various ethnic groups over the centuries. The purpose of this study was to investigate the association of genetic polymorphisms at the APOB XbaI, EcoRI and MspI restriction sites with body mass index (BMI), serum protein and lipid profiles in children of Guangxi. METHODS: Genomic DNA was extracted from 200 healthy children from Guangxi. APOB XbaI, EcoRI and MspI genotypes were determined by PCR-restriction fragment length polymorphism (RFLP) analysis. BMI was evaluated. Fasting serum levels of total protein (TP), albumin (Alb), globulin (Glo), lipoprotein (a) [Lp(a)], total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (apoA1) and apoB were measured. RESULTS: Subjects with X+ allele exhibited significantly higher BMI, and serum levels of Lp(a), TC, TG, LDL-C and apoB than those with X- allele (p<0.05), whereas for TP and Alb the opposite were found (p<0.05). E - /E- carriers had significantly higher Lp(a), TC, HDL-C, and apoA1 concentrations than did E + /E- or E + /E+ (p<0.05), whereas for TP and Alb the opposite were found (p<0.05). Higher Lp(a), TC, HDL-C, and lower TP, Alb concentrations were observed in individuals with E- allele as compared to E+ allele (p<0.05). No significant differences in BMI, serum protein and lipid parameters were determined for the polymorphism study of the APOB MspI locus (p>0 0.05). CONCLUSIONS: APOB XbaI and EcoRI restriction sites may serve as potential genetic markers affecting BMI, serum protein and lipid profiles in children from Guangxi. Living habits and diet should be modified, according to the genetic polymorphism of APOB. In addition, because the groups of rare allele carriers of XbaI and MspI polymorphisms are very small, the significance of the statistical analysis may be weak.

Association of polymorphisms at restriction enzyme recognition sites of apolipoprotein B and E gene with dyslipidemia in children undergoing primary nephrotic syndrome.

BACKGROUND: Dyslipidemia, a common complication, is very prevalent in children with primary nephrotic syndrome (PNS). Recent studies have shown that genetic basis may be involved in the onset of HLP secondary to PNS. ApoB and E have been identified as the important candidate genes for lipid abnormalities. OBJECTIVE: To investigate the association of apolipoprotein B (apoB) and E (apoE) genetic polymorphisms (Xba I, EcoR I, Msp I, and Hha I) with parameters describing the serum lipid profiles in children undergoing PNS. METHODS: Genomic DNA was extracted from 250 children diagnosed with PNS and 200 healthy controls with neither allergic nor renal disease. ApoB (Xba I, EcoR I, and Msp I) and apoE (Hha I) genotypes were determined by PCR-restriction fragment length polymorphism (RFLP) analysis. The fasting serum lipoprotein (a) [Lp(a)], total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (apoA1), apoB, and total protein from a 24-h urine sample were measured. RESULTS: No significant differences in genotypes and alleles frequencies were observed for the apoB Xba I, EcoR I, Msp I and the apoE Hha I restriction sites in PNS patients as compared to controls (P > 0.05). Patients and controls with X + allele exhibited significantly higher serum levels of Lp(a), TC, nonHDL-C, LDL-C, LDL-C/HDL-C ratio, and apoB than that with X- allele (P < 0.05), whereas for apoA1/B ratio the opposite was found (P < 0.01). E-/E- carriers had significantly higher Lp(a), TC, HDL-C, and apoA1 concentrations than did E+/E- or E+/E+ carriers in control group (P < 0.05). Healthy children carrying the rare EcoR I allele had higher mean Lp(a), TC, and HDL-C levels than homozygotes for E+ (P < 0.05). Higher Lp(a) serum concentrations were observed in patients with E- allele (P < 0.05). No significant differences in lipid parameters were determined for the apoB Msp I and apoE Hha I the polymorphisms study (P > 0.05). When genetic variations were compared with urinary protein excretion, the Xba I X- allele was more frequent in patients with elevated proteinuria (P < 0.01). CONCLUSION: Presence of Xba I X+ allele and/or EcoR I E- at the apoB gene may be risk factors for lipid abnormalities secondary to childhood PNS.

[Rapid diagnosis of 21 trisomy syndrome by fluorescence quantitative polymerase chain reaction].

OBJECTIVE: To establish a method of fluorescence quantitative PCR to detect 21 trisomy syndrome. METHODS: At first, using one pair of primer to simultaneously amplify different fragments of two highly homologous genes of the human liver-type phosphofructokinase located on chromosome 21 (PFKL-CH21) and the human muscle-type phosphofructokinase located on chromosome 1 (PFKM-CH1). Then, staining the PCR products of these homologous genes with SYBR Green I, comparing the fluorescence intensities of the bands after electrophoresis, and analyzing the data. RESULTS: The relative fluorescence intensity ratios of PFKL-CH21/PFKM-CH1 in 21 trisomy syndrome and normal individuals were 1.58+/-0.17 (mean+/-SD) and 1.00+/-0.05 (mean+/-SD), respectively; the difference between the two groups was highly significant. CONCLUSION: SYBR Green I fluorescence quantitative polymerase chain reaction is an acurate, rapid, safe and practical approach for the detection of 21 trisomy syndrome.