P21 gene variation and late-onset Alzheimer's disease in the Italian population.

BACKGROUND: Variation at the cyclin-dependent kinase inhibitor gene P21 in a patient sample of the Italian population was investigated in search of genetic factors potentially involved in sporadic late-onset Alzheimer's disease (AD). METHODS: Two single nucleotide polymorphisms (SNPs) were studied in this gene: a C>A transversion at codon 31 (ser>arg) in exon 2 (RS1801270) and a C>T transition occurring 20 bp downstream from the stop codon of exon 3 (RS1059234). RESULTS: The odd ratios were: RS1801270 A allele = 0.62 (95% CI = 0.33-1.18; p = 0.14); RS1059234 T allele = 0.57 (95% CI = 0.33-0.98; p = 0.04). In addition, a longer duration of disease was found with genotypes carrying the RS1059234 T allele (4.3 ± 2.5 years) than with those not carrying it (3.3 ± 2.1 years) (p = 0.001). CONCLUSION: In the present sample, one of the two SNPs seems in some way related to AD, since carriers of one allele were slightly protected against AD onset.

Association of ACE I/D polymorphism and recurrent miscarriages in an Italian population with a pre-modern reproductive pattern.

Angiotensin I-converting enzyme (ACE), in addition to its role in the renin angiotensin system, has a physiological function in the fibrinolysis pathway, the accurate control of which is critical for the normal development of pregnancy. Recently, the ACE I/D polymorphism was found to be associated with recurrent spontaneous miscarriages (RM). The present study analysed the relationship between ACE I/D polymorphism and the number of spontaneous miscarriages, the number of pregnancies and the number of children in a sample of 88 Italian women born before 1930, with a pre-modern reproductive behaviour. The ACE DD genotype was more prevalent among women with RM (p = 0.02). However, the women carrying the DD genotype not only had the highest number of miscarriages (p = 0.03), but also the highest number of pregnancies with an eventual complete fertility (children no = 4.4), similar to that of women carrying the other ACE genotypes. In contrast, published data on contemporary women with RM seem to indicate that the DD genotype could now be associated with a reduced reproductive success compared to the other ACE genotypes. It is suggested that this phenomenon may be the effect of the interaction between ACE genotypes and contemporary reproductive behaviours (delay in childbearing, below-replacement fertility).

An analysis of peroxisome proliferator-activated receptor gamma (PPAR-gamma 2) Pro12Ala polymorphism distribution and prevalence of type 2 diabetes mellitus (T2DM) in world populations in relation to dietary habits.

BACKGROUND AND AIM: The human peroxisome proliferator-activated receptor gamma (PPAR-gamma) is involved in lipid storage, glucose homeostasis and adipocyte differentiation. The Ala allele of the Pro12Ala polymorphism has been associated with a protective effect against T2DM. Ala allele frequencies are known for many populations, but data are absent for other interesting human groups. METHODS AND RESULTS: We examined samples from Ethiopia, Benin, Ecuador and Italy. In addition, we performed an analysis of the Pro12Ala polymorphism distribution in world populations, also in relation to T2DM prevalence and the diet lipid content. In the European populations, the Ala allele frequencies are distributed according to a latitudinal trend, with the highest in the northern and central European populations and the lowest in the Mediterranean populations. Considering the world populations, a significant inverse relationship between Ala frequency and T2DM prevalence was observed mainly in populations where energy from lipids exceeded 30% of the total energy intake. CONCLUSION: Northern Europe's cold climate has been hypothesised to have played a role in contributing to the present pattern. Moreover our analysis appears to confirm, at a population level, the protective effect of Ala allele against T2DM, already observed in case-control studies, but only in populations with a diet rich in lipids.

Screening of two mutations at exon 3 of the apolipoprotein E gene (sites 28 and 42) in a sample of patients with sporadic late-onset Alzheimer's disease.

The search for further variation at the APOE gene in a sample of patients with sporadic late-onset Alzheimer's disease (AD) and related controls revealed two different mutations in the exon 3 of the gene. One, the Leu28-->Pro, always found on an APOE e(*)4 allele, was present in five of the 94 patients and in 1 of the 157 controls. The other, Thr42-->Ala, found on an e(*)3 allele, was observed in only one AD patient, who also carried the Leu28-->Pro, but in none of the controls. In the AD patient group the allele e(*)4(-), corresponding to Leu28-->Pro, showed a frequency of 0.027, compared with only 0.003 in the controls. Compared to E3/3 and E3/2 genotypes, the risk of developing AD associated with the genotypes carrying the e(*)4 allele, the well-established risk allele for AD onset, was observed to be high (OR=3.16; 95% CI=1.62-6.20; P=0.0009), but the risk associated with genotypes carrying the Leu28-->Pro mutation was higher still (OR=10.95; 95% CI=1.25-95.75; P=0.015). The higher risk associated with this mutation was assessed by meta-analysis carried out using the data of three patient groups from a previously published study Kamboh et al. and from our study. The results indicated that, compared with all the other APOE genotypes, those carrying the Leu28-->Pro mutation were at a substantially higher risk of developing AD (OR=4.25; 95% CI=1.21-14.97).

Plasma alpha1-antichymotrypsin in Alzheimer's disease; relationships with APOE genotypes.

Inflammatory processes are thought to be important contributors to the pathogenesis of Alzheimer's disease (AD). alpha1-antichymotrypsin (ACT) is a proteinase inhibitor characteristic of acute-phase inflammation and has been identified in amyloid plaques. We analyzed the plasma ACT levels in a sample of subjects with late-onset AD and correspondent controls. Plasma ACT was higher in AD patients (62.8 +/- 20.2 mg/dl) than in controls (58.8 +/- 18.1 mg/dl), but not significantly (P = 0.13). In the AD patients regression analysis showed a positive linear relationship between ACT levels and duration of the disease (P = 0.037). Increased ACT concentrations (64.6 +/- 21.2 mg/dl) were also found in patients with greater cognitive impairment (MMSE scores < 20), but since this factor depends on the duration of the disease as well, our present data seem to indicate a complex relationship involving elevated ACT levels, disease duration and cognitive impairment. Plasma ACT was found to differ significantly according to APOE genotypes (P = 0.017), the highest levels being associated to E3-E3 homozygotes (66.1 +/- 17.8 mg/dl) and the lowest to E4-E3 subjects (53.1 +/- 18.2 mg/dl). In patients not carrying APOE*4 allele the ACT levels were higher than in controls (P = 0.014), and the relationship between ACT and disease duration was stronger than that observed in the total AD sample (P = 0.003), but it was absent in those carrying APOE*4 (P = 0.67). Taken together our results seem to suggest that inflammation is a relevant factor in AD pathogenesis for subjects with E3-E3 and E3-E2 genotypes but less important for APOE*4 carrying subjects.

Apolipoprotein E genotype and plasma levels in coronary artery disease. A case-control study in the Italian population.

OBJECTIVES: To investigate the role of the apolipoprotein B and apolipoprotein E polymorphisms in coronary artery disease (CAD) susceptibility in the Italian population and their relation to plasma lipid and apolipoprotein levels. METHODS: APOB (APOB Xbal, EcoRI, Ins/Del), and APOE (APOE Cfol) polymorphisms were analyzed in 150 male CAD patients and 110 matched controls. In the same subjects plasma lipid, apoB, and apoE levels were measured. RESULTS: No differences in the distribution of the APOB polymorphisms were observed between patients and controls. Among patients the number of e*4-carriers was significantly higher than in controls. e*4-carriers were more frequent among the hypertensive patients and had a higher systolic blood pressure (p = 0.007) than the non-e*4 carriers. The APOB Xbal polymorphism was found to influence the distribution of HDL-cholesterol. Patients showed significantly lower levels of apoE (39.29 mg/L) than controls (54.32 mg/dL) and the lowest concentrations were associated to the E4/E3 and E4/E4 genotypes. CONCLUSION: Quantitative data are consistent with the hypothesis that apoE has an anti-atherosclerotic role and suggest that the apoE quantitation could be a useful parameter for defining cardiovascular risk. e*4 allele appears to be a risk factor for CAD in the Italian population and could act by its association with low apoE levels.

Apolipoprotein E (APOE) allele frequencies in late-onset sporadic Alzheimer's disease (AD), mixed dementia and vascular dementia: lack of association of epsilon 4 allele with AD in Italian octogenarian patients.

The Apolipoprotein E (APOE) epsilon 4 allele has been found to be strongly associated with Alzheimer's disease (AD) in most studies conducted up to now, though not all investigators have established a similar association with other forms of dementia, like vascular dementia. Our study examined the APOE polymorphism in a sample of 149 dementia patients, of which there were 80 with probable sporadic late-onset AD, 16 with a mixed form of dementia (MD), and 53 with vascular dementia (VD). An elderly control sample was composed of 126 subjects. The data obtained on the whole AD sample did not confirm the association already reported with APOE epsilon 4. A difference did emerge when the subjects were subdivided on the basis of age at the examination. AD patients aged < or = 80 years significantly differed from the correspondent elderly controls, while no difference was observed between the patients aged 81 years or older and controls. This pattern could be due to a previous disadvantageous effect of the epsilon 4 allele on the subjects bearing it. A substantially similar pattern was observed in the few MD patients, while no differences were found in the two VD subgroups. The odds ratio (OR) for AD associated with at least one epsilon 4 allele was significant and equal to 3.3 (95% CI = 1.2-9.1) for the < or = 80 age class, while it was not significant and equal to 1.1 (95% CI = 0.4-2.8) for the > 80 age class. Our data indicate that in AD patients aged less than 81 years, epsilon 4 is clearly associated with AD and that it can be considered a risk factor for AD chiefly before this age.

Plasma levels of apolipoprotein E and genetic markers in elderly patients with Alzheimer's disease.

Besides apolipoprotein E (APOE) polymorphism, whose association with Alzheimer's disease (AD) has been confirmed in most of the numerous population samples studied, other markers have been investigated. In most cases the association firstly described was not confirmed in subsequent works. Since it is important to examine these associations in as many populations as possible, we investigated APOE, APOC1, APOC2, alpha-1 antichymotrypsin (ACT) and presenilin-1 (PS-1) polymorphisms in a series of elderly patients with late-onset sporadic AD from Northern Italy and in a sex and age-matched control group. We could not confirm the significantly higher frequency of the ACT*A allele among carriers of APOE e*4 allele described elsewhere, although a similar trend was observed. The APOC2 and the PS-1 distributions were similar between patients and controls. However, we observed a significant difference in the genotype and allele frequencies of APOE and APOC1: patients had higher e*4 and C1*2 allele frequencies. This finding confirms the important role for APOE in AD occurrence. In addition, APOC1 seems to be an interesting marker because, though in strict linkage disequilibrium with APOE, it seems to play an independent role in AD risk. In contrast to previously reported data, plasma apoE concentrations were similar in patients and in controls. An interaction between APOE and APOC1 polymorphisms and apoE levels was observed in patients: subjects carrying the APOE E3/E2 or the APOC1 2-2 genotype have higher apoE concentrations than those who do not.

Serum haptoglobin appearance during neonatal period is associated with acid phosphatase (ACP1) phenotype.

Erythrocyte acid phosphatase (ACP1) is a polymorphic enzyme found in many tissues and acts in vivo as a flavin-mononucleotide phosphatase. We have recently observed a relation between this enzyme and length of gestation. The present study shows that the pattern of appearance of serum haptoglobin during the neonatal period is associated with ACP1 phenotype suggesting some important function of this polymorphic enzyme in human development.

Survey of seven plasma protein polymorphisms in the Amhara and Oromo populations of Ethiopia.

The Ethiopian population is very difficult to specify due to a very high degree of intermixing among different peoples. The two groups of the present study, the Amhara and Oromo, constitute 38% and 35% of the population, respectively. In order to investigate the genetic composition of the Amhara and Oromo, genetic polymorphisms of seven plasma proteins (F13A, F13B, ORM1, AHSG, C6, C7, and APOC2), already identified as useful anthropological markers, were studied. No statistically relevant differences were found between the two groups for all of the systems examined. ORM1 and F13A showed frequencies in the range observed in other populations of Caucasoid and Negroid origin. F13B, AHSG, and C6 displayed gene frequencies and a number of variant alleles that seem particular to these two groups. No variation was observed for C7 and APOC2. Correspondence and distance analyses were used to interpret and compare the gene frequencies of the Amhara and Oromo with those of other related populations. These methods locate Ethiopians in an intermediate position between African Blacks and a group of Caucasoid populations, confirming cultural and historical data. © 1994 Wiley-Liss, Inc.

An investigation of human apolipoproteins B and E polymorphisms in two African populations from Ethiopia and Benin.

Three polymorphisms (XbaI, EcoRI, and Ins/Del) of the apolipoprotein B (APOB) gene and the polymorphism of apolipoprotein E (APOE) were investigated in two population samples of Amhara and Oromo origin from Ethiopia, and in two population samples of Bariba and Berba origin from Benin. No heterogeneity was observed within each major group. The cumulated frequencies of the APOB X+, R+, and D alleles for the Ethiopia and the Benin groups were 0.268 and 0.133, 0.958 and 0.818, 0.206 and 0.223, respectively. Regarding APOE, the cumulated allele frequencies of Ethiopia and Benin were 0.031 and 0.103 for epsilon*2 allele, 0.811 and 0.742 for epsilon*3, and 0.143 and 0.155 for epsilon*4, respectively. APOE typing performed at the protein level only in the Ethiopians revealed a variant allele, epsilon*5, found at the polymorphic level both in the Amhara and in the Oromo (cumulated frequency: 0.015). A tentative explanation for the higher frequencies of epsilon*4 and epsilon*5 alleles was sought in relation to the lifestyle and ethnicity of the two populations. Am. J. Hum. Biol. 11:297-304, 1999. Copyright 1999 Wiley-Liss, Inc.

Estrogen receptor alpha polymorphisms and fertility in populations with different reproductive patterns.

The estrogen receptor (ER) plays an important role in mediating estrogen action on target tissues. ER-alpha, the most abundant, is found in all human reproductive tissues and studies on alpha-ER knockout mice have highlighted its role in reproduction. ER-alpha gene (ESR1) polymorphisms have been associated with a variety of disorders including human infertility. In this study, we examined the association of ESR1 PvuII and XbaI polymorphisms with fertility in two populations with different reproductive patterns and precisely in a sample of healthy Italian men and women (n=178) and in a sample of healthy African-Ecuadorian women (n=57). ESR1 xx and ppxx genotypes among the Italian men were found to be associated with an above-median number of children (P=0.01 and P=0.004, respectively). ESR1 pp genotype among the Italian women showed a tendency to be associated with a lower number of abortions (P=0.04), whereas ESR1 pp and ppxx genotypes among African-Ecuadorian women were associated with a higher number of children (P=0.02 and P=0.03, respectively). These results are consistent with previous observations indicating a role of ESR1 genotypes in human infertility and give insight into the complex interactions between genotypes and reproductive behaviours in human populations.

Apolipoprotein E (APOE) allele distribution in the world. Is APOE*4 a 'thrifty' allele?

Apolipoprotein E (APOE = gene, apoE = protein) plays a central role in plasma lipoprotein metabolism and in lipid transport within tissues. The APOE shows a genetic polymorphism determined by three common alleles, APOE*2, APOE*3, APOE*4 and the product of the three alleles differs in several functional properties. APOE is involved in the development of certain pathological conditions. In particular, the APOE*4 allele is a risk factor for susceptibility to coronary artery disease (CAD) and Alzheimer's Disease (AD). In the present study we analyzed the APOE allele distribution in the world. The APOE*3 is the most frequent in all the human groups, especially in populations with a long-established agricultural economy like those of the Mediterranean basin (0.849-0.898). The frequency of APOE*4, the ancestral allele, remains higher in populations like Pygmies (0.407) and Khoi San (0.370), aborigines of Malaysia (0.240) and Australia (0.260), Papuans (0.368), some Native Americans (0.280), and Lapps (0.310) where an economy of foraging still exists, or food supply is (or was until the recent past) scarce and sporadically available. The APOE*2 frequency fluctuates with no apparent trend (0.145-0.02) and is absent in Native Americans. We suggest that the APOE*4, based on some functional properties it has and on its distribution among human populations, could be identified as a 'thrifty' allele. The exposure of APOE*4 to the contemporary environmental conditions (Western diet, longer lifespans) could have rendered it a susceptibility allele for CAD and AD. The absence of the association of APOE*4 with CAD and AD in Sub-Saharan Africans, and its presence in African Americans, seems to confirm this hypothesis.

Human placental 17 beta-estradiol dehydrogenase: enzymatic activity in the last weeks of pregnancy and electrophoretic data.

A specific electrophoretic method for human placental 17 beta-estradiol dehydrogenase (17-HSD; EC 1.1.1.62) has been performed and a sample of about 180 placentae from Italian women has been examined. A common phenotype and only one electrophoretic variant have been observed. Also 17-HSD activity has been tested. A statistically significant negative correlation has been found between 17-HSD activity and both gestational age and birth weight in the last weeks of gestation in a group of at term newborns with weight appropriate for date. This reduction in enzymatic activity is in good agreement with the data on estrone and estradiol which both show a declining rate of increase in the last weeks of pregnancy.

Effect of some thiol reagents on erythrocyte adenosine deaminase (ADA) activity.

The effect of three thiol reagents on erythrocyte adenosine deaminase (ADA) activity has been studied. Oxidized glutathione and iodoacetate do not alter ADA activity, while the treatment with p-chloromercuribenzoate at similar concentrations results in a reduction of enzymatic activity which is statistically significant only for ADA 1, but not ADA 2-1 phenotype haemolysates.

Kinetic properties of the common electrophoretic variants of human S-adenosylhomocysteine hydrolase (AHCY): the effect of four nucleoside analogue inhibitors.

Red blood cell S-adenosylhomocysteine hydrolase (AHCY) from individuals of 1, 2-1 and 3-1 phenotypes was partially purified and Km and Vmax determined in the absence and in the presence of the following inhibitors: 3-deaza-adenosine (DZA), 3-deaza-aristeromycin (DZAry), 2-chloro adenosine (2-Cl-ado) and purine riboside (or nebularine). The three phenotypes 1, 2-1, 3-1 showed similar Km (32.58, 39.22 and 34.84 microM respectively), but the ratio Km/Vmax was statistically different. DZA and DZAry appeared to be strong competitive inhibitors. The AHCY 1 phenotype was more resistant to their action, while the 3-1 variant was more sensitive. 2-Cl-ado and purine riboside were weaker inhibitors; the type of inhibition varied among the three phenotypes, but, again, the AHCY 1 phenotype was less sensitive than the other two.

C'3 polymorphism in Italy.

C'3 phenotype and gene frequencies observed in two Italian samples are reported. The allele frequencies resemble those reported for other Caucasian populations. Five different rare variants are described.

C3 polymorphism and the antibody titres in pregnancy: use of a non-barbital buffer for C3 typing.

The C3 phenotypes were examined in 391 pregnant women classified according to the level of 'immune', 'natural' and 'irregular' antibody titres. No significant association between the C3 types and antibody levels was found. The sera were also typed for C3 with a non-barbital buffer.

Polymorphisms in the apolipoprotein E gene regulatory region in relation to coronary heart disease and their effect on plasma apolipoprotein E.

In a previous study which examined the distribution of apolipoprotein E genotypes and plasma levels in a sample of male coronary heart disease (CHD) patients and controls, we found a significant excess of the genotypes carrying APOE*4 allele in CHD men (18.2%) vs. controls (9.6%) and an association between the APOE*4 allele and the lowest concentrations of apoE. In the present investigation, we re-examined in the same samples two recently identified polymorphisms in the promoter region of APOE, -491A/T and -427T/C, which may alter the level of apoE expression. No differences in the distributions of the -491A/T genotypes and alleles were observed between cases and controls (-491*A = 0.760 and 0.757 respectively). Polymorphism -427T/C showed in CHD patients an excess of -427*C allele (patients vs. controls = 0.123 vs. 0.074) and corresponding genotypes that was marginally significant. Stratification of the samples according to the presence/absence of APOE*4 showed that the excess of the -427*C allele concerned only CHD patients not carrying APOE*4 allele (patients vs. controls = 0.133 vs. 0.061; p=0.017). This result suggests that the presence of -427*C allele could represent a risk for developing CHD in subjects with E2/E2, E3/E2, and E3/E3 genotypes. Studies carried out on patients with Alzheimer's disease demonstrated that -491A/T and -427T/C polymorphisms affect the level of plasma apoE. In the present study, carried out on CHD patients and controls, the genetic variation at -427 and -491 sites of the APOE regulatory region had no apparent effect on apoE plasma concentration.

Alpha 2 HS-glycoprotein phenotype and allele distribution in continental Italy and Sardinia.

The genetic polymorphism of alpha 2 HS-glycoprotein (A2HS) was studied in continental Italy (Rome and L'Aquila) and in Sardinia (Cagliari). The two continental populations did not differ significantly in the A2HS gene distribution, whereas the Sardinian population showed an A2HS*1 frequency significantly higher than in continental Italy.