Adenosine deaminase-acid phosphatase association and the environment: A study in a continental Italian population

Type-2 diabetes mellitus and the frequency of the G22A polymorphism of the adenosine deaminase gene in a mixed population in Brazil

BACKGROUND

Most individuals diagnosed with diabetes mellitus (about 90%) have type 2 disease (T2DM). T2DM is associated with a high genetic predisposition and is characterized by changes in the secretion and action of insulin. There have been reports of increased activity of the adenosine deaminase enzyme in individuals with coronary heart disease and DM.

METHODS

We evaluated 162 patients with T2DM and 160 individuals without the disease. Additionally, a subgroup of 81 individuals at higher risk of developing cardiovascular diseases was formed from the group of patients with diabetes on the basis of their serum levels of high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc) and triglycerides. PCR-RFLP was performed to analyze the TaqI polymorphism G428A of the ADA gene; this technique identifies the ADA*01 and ADA*02 alleles.

RESULTS

Genotype frequencies were calculated for three patient groups, as follows. Patients with diabetes: ADA*01;*01 (142/159, 89.3%), ADA*01;*02 (16/159, 10.1%) and ADA*02;*02 (1/159, 0.6%); control group: ADA*01;*01 (146/160, 91.3%), ADA*01;*02 (12/160, 7.5%) and ADA*02;*02 (2/160, 1.3%); patients at risk of cardiovascular disease: ADA*01;*01 (71/78, 91.0%), ADA*01;*02 (7/78, 9.0%) and ADA*02;*02 (0/78, 0.0%).

CONCLUSION

No statistically significant differences between the groups were observed in the genotype and allele frequencies. However, this fact does not rule out the need for further studies on the frequencies of this polymorphism in the Brazilian population, on any association with ADA enzyme activity, and on other risk factors that can affect the quality of life of Brazilian patients with T2DM.

Is there a role of ACP1-ADA1 genetic complex in immune reaction? Association with T1D and with past malarial morbidity

In this article, we confirm the positive association of acid phosphatase locus 1 (ACP1)*A/adenosine deaminase locus 1 (ADA1)*2 gametic type with type 1 diabetes (T1D) previously reported and show a negative correlation between the frequency of this gametic type with past malarial morbidity in Sardinia. One hundred seven adult women with T1D and 385 healthy adult women from the Caucasian population of Central Italy have been studied. Data on 1384 children from the central area of Sardinia have also been reexamined. T1D subjects show a highly significant increase of ACP1*A/ADA1*2 gametic type compared with healthy subjects from the same population (P = 0.003). The frequency of ACP1*A/ADA1*2 gametic type is decreasing with increasing past malarial morbidity. Because ADA1*2 allele decreases the activity of *A allele and since low ACP1 activity decreases Zeta-chain-associated protein kinase with molecular weight 70 kDa (Zap70) activity resulting in weak T-cell receptor signalling an epistatic interaction involving ADA1, ACP1 and Zap70 seems a likely mechanism for the associations observed.