1,721,064 research outputs found
Acid phosphatase locus 1 (ACP1): Possible relationship of allelic variation to body size and human population adaptation to thermal stress - A theoretical perspective
No full textThe acid phosphatase locus 1 (ACP1) codes for a low molecular weight phosphotyrosine protein phosphatase that has the important action of dephosphorylating tyrosine phosphorylated proteins and peptides and a second important role in modulating flavin cofactor levels and the activity of flavo-enzymes. These functions significantly influence cell division, differentiation, and growth. Two alleles (ACP1*A and ACP1*B) reach polymorphic frequencies at the ACP1 locus in all human populations, while the ACP1*C and ACP1*R alleles reach polymorphic frequencies in restricted geographical regions. The worldwide distribution of these alleles, and data from several clinical studies, strongly suggest that the ACP1 locus functions to modulate growth and that selection at this locus is a component of the selective processes influencing body mass and human population adaptation to thermal stress. The ACP1*A allele reaches highest frequencies at extreme latitudes and appears to be associated with maximizing body mass and adaptation to cold stress, whereas the ACP1*B allele reaches highest frequencies in tropical and subtropical environments and appears to be associated with minimizing body mass and adaptation to heat stress. The high frequency of the ACP1*C allele at northern latitudes, where ACP1*A allele frequencies are elevated, may be a mechanism for limiting fetal and maternal complications associated with fetal macrosomia and adult obesity in populations where protein and calorie intake are relatively hig
Further Observations on Associations Between the ADA Gene and Past Malaria Morbidity in Sardinia.
No full textObjectives: Adenosine Deaminase (ADA) contributes to the regulation of adenosine concentration and in turn to T cell activation. Genetic variability of ADA activity may have, therefore, an important role in resistance to malaria.
Indeed, previous studies in Sardinia have shown a lower frequency of ADA1*2 allele (associated with low ADA activity)
in areas, where malaria was heavily endemic compared to areas where malaria was not endemic. We have now studied
the ADA2 locus, another polymorphic site with two alleles ADA2 *1 and ADA2 *2 within the ADA gene.
Methods: In the area of Oristano (where malaria was endemic in the past) 51 consecutive newborns and in the area
of Nuoro (where malaria was not as endemic) 48 consecutive newborns were examined.
ADA1 and ADA2 genotypes were determined by DNA analysis.
Results: The low frequency of the ADA1*2 allele in the area where malaria was endemic is confirmed. The frequency
of the ADA2*2 allele is higher in Oristano than in Nuoro resulting in a higher frequency of the ADA1*1/ADA2*2 haplotype
in Oristano as compared to Nuoro. This suggests a selective advantage of this haplotype in a malarial
environment.
Conclusions: The ADA gene shows other polymorphic sites further studies on their role in human adaptation to
malaria could be rewarding
Coronary Artery Disease: Evidence of Interaction between PTPN22 and p53 Genetic Polymorphisms
No full textObjectives: We recently reported an association between the PTPN22 genetic polymorphism and coronary artery disease (CAD) in nondiabetic subjects. Since recent studies suggest that p53 may be involved in coronary atherosclerosis, we have investigated a possible interaction between PTPN22 and p53 codon 72 genetic polymorphisms regarding their effects on susceptibility to CAD in nondiabetic subjects. Methods: The genotypes of p53 codon 72 and PTPN22 were determined by DNA analysis in 128 nondiabetic subjects with CAD, 122 healthy blood donors and 117 nondiabetic subjects with cardiovascular diseases without CAD. Results: In subjects with the *Arg/*Arg genotype of p53 codon 72, no association was observed between CAD and PTPN22. However, this association was very strong in subjects carrying the *Pro allele of p53 codon 72. Subjects carrying both the *T allele of PTPN22 and the *Pro allele of p53 were overrepresented in CAD nondiabetic cases relative to the other two groups (p = 0.001). Conclusions: Since both p53 and PTPN22 are involved in autoimmune inflammation, an interaction between the two systems appears biologically plausible. In the analysis of multifactorial disorders, the simultaneous analysis of multiple genes functionally related to diseases will provide a more productive approach than studies of single genetic factors performed from a Mendelian perspective
Diabetic complications and the genetics of signal transduction. A study of retinopathy in NIDDM
No full textCytosolic low molecular weight acid phosphatase (ACP1) is a high polymorphic phosphotyrosine-protein-phosphatase involved in signal transduction. In NIDDM subjects we have found that ACP1 genotype is a highly significant predictor of retinopathy, suggesting that genetic variability of signal transduction may have an important role in the susceptibility to this complication. Adenosine deaminase, ABO blood groups and several clinical variables have been also considered. The results point out the importance of interactions between genetic systems. Among non-genetic variables dislipidemia and treatment with insulin are significantly associated with retinopathy
Phosphotyrosine-protein-phosphatase and diabetic disorders. Further studies on the relationship between low molecular weight acid phosphatase genotype and degree of glycemic control
Full text linkWe have studied a new sample of 276 NIDDM patients from the population of Penne (Italy). Comparison of the new data with those of 214 diabetic pregnant women from the population of Rome reported in a previous paper has shown that the pattern of association between low molecular weight acid phosphatase genotype and degree of glycemic control is similar in the two classes of diabetic patients. Among nonobese subjects the proportion of ACP1*A (the allele showing the lowest enzymatic activity) is lower in diabetic patients with high glycemic levels (mean value greater than 8.9 mmol/l) than in diabetic patients with a low glycemic level (mean value less than 8.9 mmol/l). Among obese subjects no significant association is observed between glycemic levels and ACP1. Among nonobese subjects the concentration of f isoform of ACP1 is higher in patients showing a high glycemic level than in patients showing a low glycemic level. No significant difference is observed for s isoform
Genetic variability within Adenosine Deaminase gene and uterine leiomyomas
No full textThe recent observation of an association of colon cancer with two polymorphic sites within the Adenosine Deaminase (ADA) gene suggests an involvement of these polymorphisms in the development of solid tumors. This prompted us to search for a similar association in uterine leiomyomas
A study of human growth hormone and insulin gene regions in relation to metabolic control of non-insulin-dependent diabetes mellitus
No full textThe possible association of human growth hormone (hGH) and insulin (INS) gene regions with metabolic control in diabetes was investigated in 98 subjects with non-insulin-dependent diabetes mellitus (NIDDM); 54 control subjects from the same population were also studied. Two polymorphic restriction sites in the region of the hGH cluster (BGLIIA and BGLIIB) show significant association with both glycemic and hemoglobin A1c (HbA1c) levels. Mean values for plasma glucose and HbA1c show a maximum in the BGLIIA *1/*1 genotype and a minimum in the BGLIIA *2/*2 genotype. Mean values for plasma glucose and HbA1c show a maximum in the BGLIIB *1/*2 genotype. The BGLIIA*2/BGLIIB*1 haplotype shows a negative correlation with plasma glucose and HbA1c levels. Since the two markers are located in the area surrounding the hGH-V locus, the expression of this gene in NIDDM warrants further investigatio
Ak(1) genetic polymorphism and season of conception
No full textOBJECTIVE: The season of conception affects human reproduction, intrauterine growth, neonatal parameters, sex ratio, cognitive development and, in adult life, performance in many fields. Associations between polymorphic enzymes and season of conception have been also reported. In this study we searched for a possible association between season of conception and adenylate kinase locus 1 (Ak(1)). STUDY DESIGN: Two samples of 381 and 248 consecutively newborn infants from two Italian cities with different geographical positions and climatic conditions were considered. Three way contingency table analysis and Student t-test analysis were performed. RESULTS: Ak(1)2-1 phenotype is more frequent in males conceived in the summer-autumn period than in those conceived in winter-spring and this association depends on maternal Ak(1) phenotype (p=0.001). There is also an interaction between season of conception and Ak(1) phenotype concerning their effects on sex ratio and birth weight. CONCLUSION: The present data suggest a complex interaction involving seasonal cycles, maternal and foetal Ak(1) genotype and sex of foetus concerning their effects on intrauterine selection and neonatal parameters
Foetal macrosomia in diabetic pregnancy. Further data on the association with maternal PGM1 genotype
No full textThe pattern of associations between maternal phosphoglucomutase locus 1 (PGM1) and foetal macrosomia in diabetic pregnancy has been compared with that observed in normal pregnancy. In diabetic pregnancy a substantial increase of macrosomic infants, as compared to normal pregnancy, is observed only among women homozygous for PGM1(1) allele. Also neonatal hypoglycemia is much more frequent in newborns from PGM1(-1) mothers than in newborns from other mothers. Since enzymatic activity of PGM1(-1) phenotype is lower as compared to other PGM1 phenotypes, this may influence glycaemic level and/or its stability in diabetic pregnant women with unfavourable effects on the metabolic and developmental patterns of the foetu
- …
