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Objective: The purpose of this study is to examine the time-related changes of alveolar bone in 2D images quantitatively and to estimate age groups based on the change index., Materials and Methods: The 238 panoramic X-ray images and 140 CT panoramic reconstructed images of the permanent dentition period were used to examine age-related changes. Comparisons between the younger age group and each of the other age groups were calculated using the landmark method of Procrustes analysis. As aging changes were observed in each age group, age estimation was performed using antemortem panoramic X-ray images and postmortem CT images so that they could be used in practice. The CT images used in the age estimation were performed using forty-two postmortem CT panoramic reconstructed images of known age submitted to the judicial autopsy., Results: Both panoramic and CT images showed changes in the alveolar bone over time. Age estimation using postmortem CT images provided a certain assessment., Conclusion: In this study, clinically observed changes in alveolar bone over time were quantified on the images. Furthermore, the possibility of age estimation by alveolar bone was also suggested. The use of an updatable clinical database that can be stored in coordinate values offers the potential for age estimation in line with the times., Competing Interests: Declaration of Competing Interest There are no conflicts of interest to declare., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Our study was designed to examine the correlation between single nucleotide polymorphism (SNP) in the endoplasmic reticulum aminopeptidase 1 (ERAP1) gene, specifically focusing on rs27434, and plural tissue weight. We conducted this investigation using autopsy samples from the Japanese population. Blood samples were collected from 178 Japanese subjects who had undergone autopsies in Shimane Prefecture. Genomic DNA was subsequently extracted from these samples. SNP (rs27434, G＞A substitution) was analyzed by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis. In the present study, rs27434 exhibited a statistically significant association with brain weight (g) in both female and male individuals. Among males, rs27434 displayed significant relationships with liver weight (g), and body surface area (m 2 ). In females, rs27434 was significantly related to the length of the appendix. Across both genders, individuals with GA and AA genotypes tended to exhibit higher levels in these respective measurements compared to those with the GG genotype. These results suggest that genetic variant of ERAP1 gene may influence the weight of the organs. To the best of our knowledge, this is the first study investigating the interaction between the association of rs27434 in the ERAP1 gene and data routinely measured at autopsy, such as tissue weight. However, conducting further investigations with larger population samples could provide more comprehensive insights to clarify this issue., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Periodontitis is one of the most common chronic inflammatory disorders in adults. Although clinical studies have suggested a causal relationship between periodontitis and major depression (MD), the biological mechanisms by which periodontitis instigates MD are unknown. We investigated whether a systemic administration of lipopolysaccharide (LPS) from Porphyromonas gingivalis ( Pg ), a major Gram-negative pathogen of periodontitis, causes depressive-like behavior and glial activation in the hippocampus and the prefrontal cortex (PFC), which are MD-related brain regions., Materials and Methods: Eight-week-old male Sprague Dawley rats were randomly divided into a behavioral test group and an immunohistochemistry group. The rats in each group were further assigned to the sham injection (saline) and Porphyromonas gingivalis -lipopolysaccharide ( Pg -LPS) injection protocols. The rats received an intraperitoneal injection of saline or Pg -LPS with gradually increasing doses (day 1: 0.5, day 2: 0.5, day 3: 0.75, day 4: 0.75, day 5: 1.0, day 6: 1.0, and day 7: 1.0 mg/kg of body weight) for seven consecutive days. After the systemic administration, the behavior test group underwent the forced swimming test (FST) and Y-maze test. For the immunohistochemistry group, we quantified the immunoreactivity for microglial Iba-1 (ionized calcium-binding adapter molecule 1) and astrocytic glial fibrillary acidic protein (GFAP) in the hippocampus (dentate gyrus [DG], cornu ammonis [CA1 and CA3]) and PFC (prelimbic [PrL] and the infralimbic [IL]) areas., Results: The FST immobility time in the Pg -LPS group was significantly longer than that in the sham group. In the Y-maze test, a significant decline in spontaneous alternation behavior was observed in the Pg -LPS group compared to the sham group. The peripheral administration of Pg -LPS significantly increased the immunoreactivity for Iba-1 in the CA3 and PrL. Pg -LPS injection significantly increased the immunoreactivity for GFAP in the DG, CA1, and CA3., Conclusions: The major result of this study is that a repeated systemic administration of Pg -LPS caused depressive-like behavior and both microglial and astrocytic activation in rats. This finding may comprise biological evidence of a causal relationship between periodontitis and MD., Competing Interests: The authors declare no conflict of interest., (© 2023 The Author(s). Published by IMR Press.)

Objective: In recent years, personal identification has been performed using antemortem panoramic X-ray images and postmortem-CT images. Using these, we have developed a personal identification method that focuses on the alveolar bone. This study examined the effectiveness of this method and aimed to implement a reproducible system., Materials and Methods: For personal identification, a total of 633 CT images and panoramic X-ray images belonging to three groups with different conditions were used.　These images were 160 sets in the same person group and 96,820 in the other groups. The similarity of alveolar bone images was calculated using the landmark method of Procrustes analysis. The processes were system implemented and the methodology was validated., Results: The ability to identify between the same person group and other person groups showed 0.9769 as the area under the curve (AUC: ROC curve). At the cutoff value of 4.978, there was no false rejection rate, but false acceptance rate was slightly higher., Conclusion: This method was useful as a screening method for personal identification. In addition, system implementation was efficient and reduced human error. In the future, we aim to realize a more efficient personal identification method using distortion-corrected images and including auto-detective landmarks using deep learning., Competing Interests: Declarations of interest There are no conflicts of interest to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Cell-free DNA (cfDNA) is released into the plasma of patients with cardiac disease. Here, the source and mechanism of plasma cfDNA release in patients with myocardial infarction (MI) and other cardiac diseases ( n  = 59) were investigated. Plasma levels of various markers including M30 (apoptosis), M65 (apoptosis and necrosis), cyclophilin A (CyPA) (necrosis), and myeloperoxidase (MPO) (neutrophil activation) were assayed. The plasma cfDNA concentrations in MI and other cardiac diseases were significantly higher than that in the healthy control subjects. Significant differences were not observed among the cardiac disease patients (MI and other cardiac diseases) and healthy control subjects in M30, M65, and CyPA levels. In contrast,the MPO levels were significantly elevated in cardiac disease patients when compared to control groups, and MPO levels in MI patients were significantly higher than other cardiac diseases patients. These results suggest that cfDNA is mainly released by neutrophils via NETosis in addition to apoptosis except for epithelial apoptosis in patients with cardiac disease and the degree is greater in MI patients. The results from this study provide basic information for diagnosis marker of MI., Competing Interests: Disclosure of Potential Conflicts of InterestThe authors declare that they have no conflicts of interest., (© The Author(s), under exclusive licence to Association of Clinical Biochemists of India 2022.)

Cell-free DNA (cfDNA) originates from apoptotic and/or necrotic cells. Few reports are available that examine cfDNA from postmortem samples. Therefore, this study investigated differences between postmortem and biogenic subjects in concentration and fragment distribution of serum cfDNA. We also clarified features of serum cfDNA in postmortem subjects. The results revealed that postmortem subjects had significantly higher cfDNA concentrations than healthy controls and patients with cardiac disease. Serum cfDNA concentrations increased slightly with postmortem interval in subjects who died of asphyxia, and they were slightly higher in subjects who died from internal vs. external causes. Microchip electrophoresis of serum cfDNA revealed a fragment larger than 10,000 bp in only two postmortem subjects; we speculate that the fragment may have originated from necrotic cells. A relatively high concentration of one 150-200 bp fragment was characteristic of postmortem samples. This fragment may have been derived from apoptosis or other processes. We also observed ladder fragments in some subjects who died from external causes. Although additional research is needed for verification, serum cfDNA concentrations and fragment patterns possibly be used as a tool to estimate postmortem intervals and cause of death., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Each year in Japan from 1990 to 1997, approx. 21,000-24,000 individuals committed suicide. In 1998, the number of suicides increased to >30,000, and a trend of high suicide numbers then persisted for >10 years. Although Japan's annual number of suicides has recently been decreasing, it remains among the highest worldwide. Herein, we assessed the annual suicide data (numbers and rates) related to three economic and life indicators: (1) the difference between actual income and consumer spending of one average month per year in one household, (2) the annual difference between exports and imports, and (3) the annual total debt determined by statistical analyses for both sexes/males/females during the 40-year period from 1979 to 2018 in Japan. Our findings indicated that [1] total debt may be associated with both the number of suicides and the suicide rate for both sexes, for males, and for females, and [2] the difference between actual income and consumer spending may be associated with both the number of suicides and the suicide rate only in females. These findings revealed factors that are clearly suicide-related, and it is necessary to design suicide prevention strategies based on the factors. Relevant public and private entities should become aware of the involvement of both debt and the difference between income and spending in suicide trends as they plan suicide prevention measures. Further analyses of suicide data should be performed in a wide range of fields including legal medicine, toward a greater understanding of suicide risk factors., (Copyright © 2020. Published by Elsevier B.V.)

Circulating cell-free DNA (cfDNA) has been directly related to cancer, diabetes, stroke, systemic lupus erythematosus, trauma, rheumatoid arthritis, inflammation, infection, and myocardial infarction (MI). In this study, plasma cfDNA was extracted from the plasma of cardiac disease patients and the cfDNA fragment distribution as well as the relationships between cfDNA concentration and deoxyribonuclease I (DNase I) activity enzyme implicated in double-stranded DNA processing were examined. Results revealed that the cfDNA concentrations in patients with MI and cardiac angina were significantly higher than that in healthy control subjects. Microchip electrophoresis of plasma cfDNA revealed a single fragment (150-200 bp) in some healthy control subjects and three fragments (150-200 bp, 300-400 bp, and 500-600 bp) in all cardiac patient samples. Moreover, a cfDNA ratio of 150-200 bp/500-600 bp was significantly more prevalent in MI patients than in patients with other cardiac diseases (chest pain, cardiac angina, atrial fibrillation and cardiac failure). In addition, a positive correlation between DNase I activity and cfDNA concentration was observed. These results suggest that the plasma cfDNA in cardiac disease patients may originate from apoptosis and that the 150-200 bp/500-600 bp ratio for cfDNA may be a novel diagnostic indicator for MI., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Genetic variants, such as single nucleotide polymorphisms (SNPs), in the deoxyribonuclease I (DNase I) gene which remarkably reduce or abolish the activity are assumed to be substantially responsible for the genetic backgrounds determining susceptibility to autoimmune dysfunction. Here, we evaluated many genetic variants, including missense and nonsense SNPs, and indel (inframe) variants in the gene, potentially implicated in autoimmune diseases as functional variants resulting in altered activity levels. Eighteen missense and 7 nonsense SNPs, and 9 indel (inframe) variants were found to result in loss of function and disappearance of DNase I activity. Furthermore, considering the positions in the DNase I protein corresponding to the various nonsense SNPs, all of the other nonsense SNPs and frameshift variants registered in the Ensembl database ( https://asia.ensembl.org ) appear likely to exert a pathogenetic effect through loss of the activity. Accordingly, a total of 60 genetic variants in the DNase 1 gene (DNASE1) inducing abolishment or marked reduction of the DNase I activity could be identified as genetic risk factors for autoimmunity, irrespective of how sparsely they were distributed in the population. It was noteworthy that SNP p.Gln244Arg, reportedly associated with autoimmunity and reducing the activity to about half of that of the wild type, and SNP p.Arg107Gly, abolishing the activity completely, were distributed worldwide and in African populations at the polymorphic level, respectively. On the other hand, with regard to copy number variations in DNASE1 where loss of copy leads to a reduction of the in vivo enzyme activity, only 2 diploid copy numbers were distributed in Japanese and German populations, demonstrating no loss of copy. These exhaustive data for genetic variants in DNASE1 resulting in loss or marked reduction of the DNase I activity are highly informative when considering genetic predisposition leading to autoimmune dysfunction.

Deoxyribonucleases (DNases) might play a role in prevention of autoimmune conditions such as systemic lupus erythematosus through clearance of cell debris resulting from apoptosis and/or necrosis. Previous studies have suggested that variations in the in vivo activities of DNases I-like 3(1L3) and II have an impact on autoimmune-related conditions. The genes for these DNases are known to show copy number variations (CNVs) whereby copy loss leads to a reduction of the in vivo activities of the enzymes, thereby possibly affecting the pathophysiological background of autoimmune diseases. Using a simple newly developed quantitative real-time PCR method, we investigated the distributions of the CNVs for DNASE1L3 and DNASE2 in Japanese and German populations. It was found that only 2 diploid copy numbers for all of these DNASE CNVs was distributed in both of the study populations; no copy loss or gain was evident for any of the autoimmune-related DNase genes. Therefore, it was demonstrated that these human autoimmune-related DNase genes show low genetic diversity of CNVs resulting in alterations of the in vivo levels of DNase activity., Competing Interests: The authors have declared that no competing interests exist.

Recently it has been recognized that a considerable number of copy number variations (CNVs) are associated with diseases and other complex human traits. In our previous study, we developed a simple quantitative real-time PCR (Q-PCR) method for analysis of CNV copy number, which had the advantage of obviating the need for reference DNA with a known copy number. Using DNA samples obtained from 231 Japanese individuals, we applied this method for analyzing the copy number of a candidate CNV associated with body height, located in the neural precursor cell expressed, developmentally down-regulated 4-like, E3 ubiquitin protein ligase (NEDD4L) gene. In addition, the appropriateness of the results was evaluated and confirmed by quantification of amplicons with an Agilent 2100 Bioanalyzer. The NEDD4L gene encodes a member of the Nedd4 family of HECT domain E3 ubiquitin ligases. The target CNV located in the intron has been found to be significantly associated with height variation in Chinese. However, it remains unknown whether such an association exists in other populations, including Japanese. Analysis of the correlations between copy number and body height using ANOVA revealed no statistically significant correlations in Japanese., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Iron is bound to mobile transferrin (TF) and ferritin in blood. TF receptors (TFRC and TFR2) regulate intracellular iron by delivering iron from TF into the cytoplasm. In this study, we examined the effects of 10 single nucleotide polymorphisms (SNPs) in each of the genes for TF and TF receptors on blood iron concentrations in Japanese subjects. Blood iron levels were determined by microwave plasma-atomic emission spectrometry and the SNPs were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Blood iron levels in males were significantly higher than those in females. Therefore, the analysis was performed only in males. Blood iron concentrations did not correlate with age and postmortem intervals in males. Among the 10 SNPs in TF, TFRC, and TFR2 genes, significant associations were observed between TF genotypes (rs12769) and male iron concentrations. Individuals with genotype GG in rs12769 had significantly higher blood iron concentrations than those with GA. Previous studies have shown the association between high tissue iron concentrations and disease, liver iron levels are higher in infants dying from sudden infant death syndrome and decreased blood iron concentrations were observed in critically ill children. Therefore, rs12769 in TF might be related to diseases and mortality risk., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Zinc homeostasis in cells depends on zinc transporters, which are divided into 2 families: ZnT (SLC30A) and ZIP (SLC39A). In this study, we examined the effect of 20 single nucleotide polymorphisms (SNPs) in 10 genes encoding zinc transporters on blood zinc concentration in Japanese subjects (n = 102). Blood zinc levels were determined by microwave plasma-atomic emission spectrometry, and SNPs were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Among the 20 SNPs examined, 3 SNPs (SLC30A3 rs11126936, SLC39A8 rs233804, and SLC39A14 rs4872479) were significantly associated with blood zinc concentration. Individuals with genotype TT and TG in rs11126936 showed significantly higher blood zinc concentrations than those with GG. As for rs233804, individuals harboring the A allele had significantly higher blood zinc concentrations than those without this allele. Furthermore, the genotype TT and TG in rs4872479 had significantly higher blood zinc concentrations than those with GG. Among these three SNPs, combination of SLC30A3 rs11126936 and SLC39A8 rs233804 may strongly affect blood zinc levels. This study is the first comprehensive investigation of the effect of SNPs in genes encoding zinc transporters on blood zinc concentration. Adverse effects of zinc deficiency are reported and above 3 SNPs may be related to genetic susceptibility to zinc deficiency., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Dysfunction of DNase I-like 2 (DNase 1L2) has been assumed to play a role in the etiology of parakeratosis through incomplete degradation of DNA in the epidermis. However, the pathogenetic background factor for such pathophysiologic conditions remains unknown. In this context, non-synonymous single-nucleotide polymorphisms (SNPs) in DNASE1L2 that would potentially result in loss of in vivo DNase 1L2 activity might serve as a genetic risk factor for such pathophysiologic conditions. Our aim was to effectively survey the non-synonymous SNPs of DNASE1L2 that would produce a loss-of-function variant of the enzyme together with a genetic distribution in the various populations. Here, the effects of all of the SNPs predicted by PolyPhen-2 analysis to be "probably damaging" (score = 1.000), and derived from frameshift/nonsense mutations, on the activity of DNase 1L2 were examined using the corresponding DNase 1L2 variants expressed in COS-7 cells. Genotyping of these SNPs was also performed in three ethnic groups including 14 different populations. Among the 28 SNPs examined, the minor allele of 23 SNPs was defined as a loss-of-function variant resulting in loss of DNase 1L2 function, indicating that Polyphen-2 analysis could be effective for surveys of at least non-synonymous SNPs resulting in loss of function. On the other hand, these minor alleles were not distributed worldwide, thereby avoiding any marked reduction of the enzyme activity in human populations. Furthermore, all of the 19 SNPs originating from frameshift/ nonsense mutations found in DNASE1L2 resulted in loss of function of the enzyme. Thus, the present findings suggest that each of the minor alleles for these SNPs may serve as one of genetic risk factors for parakeratotic skin diseases such as psoriasis, even though they lack a worldwide genetic distribution.

Recent studies of copy number variations (CNVs) associated with physical features, such as body mass index, body height or bone length, have suggested that such CNVs could serve as markers in forensic cases involving unidentified individuals. However, the process of cataloging CNVs has been slow because of the cumbersome nature and low reliability of the procedures involved. Here we describe a simple quantitative real-time PCR (Q-PCR) method for screening of medicolegally useful CNVs, which does not require reference DNA with known copy number. The first step is to prepare a chimeric plasmid vector including one copy each of the single-copy gene-specific sequence as the internal standard, and the target CNV-specific sequence. To assess the validity of this new method, we analyzed CNVs in the LTBP1 and ETV6 gene regions, both of which are candidate CNVs associated with body height. The PCR efficiencies for the single-copy (reference) gene and the target CNV were similar, indicating that quantitation was reliable. Furthermore, simulated analysis of the LTBP1 CNV using mock samples prepared by mixing vectors in varying proportions showed that this analytical method allowed correct determination of the LTBP1 copy number. These results demonstrated that our simple method has considerable potential for screening of trait-related CNVs that would be useful for forensic casework., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A 45-year-old male, an alcohol addict with asthma, was found dead in his home, after several days of continued drinking. A forensic autopsy was performed 3days after the discovery of his death in order to specify the cause of death. A longitudinal perforation penetrating all layers of the esophagus measuring 1.8cm was present on the left wall approximately 2.0cm from the gastroesophageal junction. There were 1900mL of greenish to brownish turbid liquid in the left pleural cavity and 150mL of greenish viscous liquid in the stomach. Histopathologically, an infiltration of numerous neutrophils was evident in the submucosa layer, proper muscular layer, and serous membrane of the esophagus, corresponding to the esophageal laceration. The serum C-reactive protein (CRP) concentration was determined to be 3.1mg/dL. The alcohol concentrations were determined to be 1.49mg/g in the right cardiac blood, 1.31mg/g in the left cardiac blood, and 2.48mg/g in urine. Based upon the autopsy and histopathological findings, as well as the biochemical and toxicological analyses, we concluded that the cause of death was respiratory failure by pleural effusion, resulting from spontaneous esophageal perforation. This was the first report of a spontaneous esophageal perforation eventually causing respiratory failure., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objective: To continue our previous investigations, we have extensively investigated the function of the 61, 41, and 35 non-synonymous single nucleotide polymorphisms (SNPs) in the human genes encoding DNASE1, DNASE1L3, and DNASE2, respectively, potentially relevant to autoimmune diseases., Methods: The site-directed mutagenesis was employed to amino acid-substituted constructs corresponding to each SNP. The COS-7 cells were transfected with each vector and DNase activity was assayed by the single radial enzyme diffusion method. By using PolyPhen-2, changes in the DNase function of each non-synonymous SNP were predicted. Genotyping of all the non-synonymous SNPs was performed in 14 different populations including 3 ethnic groups using the polymerase chain reaction followed by the restriction fragment length polymorphism method., Results: Expression analysis demonstrated these SNPs to be classified into four categories with regard to the effect on DNase activity: SNPs not affecting the activity level, ones reducing it, ones abolishing it, and ones elevating it. In particular, 9, 5, and 4 SNPs producing a loss-of-function variant of the enzymes in DNASE1, DNASE1L3, and DNASE2, respectively, were confirmed. SNPs producing DNase loss of function can be estimated by PolyPhen-2 to be "probably damaging" with a high accuracy of prediction. Almost all of these functional SNPs producing a loss of function or substantially low activity-harboring forms exhibited a mono-allelic distribution in all of the populations., Conclusion: A minor allele of functional SNPs, despite the remarkably low genetic heterogeneity of the SNPs, might be a genetic risk factor for autoimmune diseases.

Purpose: X-ray repair cross-complementing group 1 (XRCC1) repairs single-strand breaks in DNA. Several reports have shown the association of single nucleotide polymorphisms (SNPs) (Arg194Trp, Pro206Pro, Arg280His, Arg399Gln) in XRCC1 to diseases. Limited population data are available regarding SNPs in XRCC1, especially in African populations. In this study, genotype distributions of four SNPs in worldwide populations were examined and compared with those reported previously., Materials and Methods: Four SNPs (Arg194Trp, Pro206Pro, Arg280His, Arg399Gln) in XRCC1 from genomic DNA samples of 10 populations were evaluated by using polymerase chain reaction followed by restriction fragment length polymorphism analysis., Results: The frequency of the minor allele corresponding to the Trp allele of XRCC1Arg194Trp was higher in Asian populations than in African and Caucasian populations. As for XRCC1Pro206Pro, Africans showed higher minor allele frequencies than did Asian populations, except for Tamils and Sinhalese. XRCC1 Arg280His frequencies were similar among Africans and Caucasians but differed among Asian populations. Similarly, lower mutant XRCC1 Arg399Gln frequencies were observed in Africans., Conclusions: This study is the first to show the existence of a certain genetic heterogeneity in the worldwide distribution of four SNPs in XRCC1., (© 2014 Wiley Periodicals, Inc.)

A 56-bp variable number of tandem repeat polymorphism is confirmed in intron 4 of the human deoxyribonuclease I (DNase I) gene (HumDN1). The purpose of the present study was to document global ethnic variations of allelic frequencies in HumDN1 VNTR polymorphisms. In this study, HumDN1 VNTR polymorphisms in 11 worldwide populations were examined by polymerase chain reaction and compared with those reported previously. Fifteen genotypes were identified in these 11 populations. Novel genotypes were found: 1/2 was observed in Ghanaians and mestizos, 3/6 was in Tamangs, 4/6 was in Tibetans and Nahuas, 6/6 was in Sinhalese. The African population showed the highest frequency for the HumDN1(∗)3 allele. Among Asian populations, the different genotype distribution was observed. The predominant allele in Mongolian, Korean, Japanese, and Chinese populations was HumDN1(∗)3, followed by HumDN1(∗)4, and then HumDN1(∗)5. In Chinese from South China, Tamangs, and Sinhalese, HumDN1(∗)4 and HumDN1(∗)5 were predominant. The allele frequency for HumDN1(∗)4 was high in three Mexican populations, but a significant difference was observed between Nahuas and Huicoles. Germans and Turks showed a similar distribution. This study is the first to show the existence of a certain genetic heterogeneity in the worldwide distribution of HumDN1 VNTR polymorphism., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

In the present study, we evaluated all of the 35 non-synonymous SNPs in the gene encoding DNase I-like 2 (DNase 1L2), implicated in terminal differentiation of keratinocytes, to seek a functional SNP that would potentially affect the levels of in vivo DNase 1L2 activity. Based on a compiled expression analysis of the amino acid-substituted DNase 1L2 corresponding to each of the 35 non-synonymous SNPs in the gene, these 35 SNPs were grouped into 4 classes according to the alteration of catalytic activity caused by the corresponding amino acid substitution in the DNase 1L2 protein; we were able to identify 12 non-synonymous SNPs as functional SNPs abolishing or substantially reducing the activity. Almost all of the amino acid residues corresponding to the SNPs abolishing the activity were completely or highly conserved in not only the DNase I family, but also animal DNase 1L2. Each of the minor alleles of these functional SNPs producing a loss-of-function or low activity-harboring variant was absent in 14 different populations derived from 3 ethnic groups, allowing us to assume that DNASE1L2 is generally well conserved with regard to these non-synonymous SNPs, thereby avoiding any marked reduction of the enzyme activity in human populations. However, it seems likely that each of the minor alleles for these SNPs may serve as a genetic risk factor for multiple skin diseases such as psoriasis, in which there is an aberrant retention of nuclear chromatin in cornified keratinocytes through incomplete DNA degradation., (Copyright © 2015 Elsevier B.V. All rights reserved.)

ZnO nanoparticles (NPs) have been widely used in various commercial products. Application of ZnO NPs is expected to apply to cancer diagnosis and therapy, used as drug delivery carriers. In the present study, the lethal dose 50 (LD50) of intravenously administered ZnO NPs (0.3 mg/kg) was calculated in mice. Blood kinetics and tissue distribution of a toxic dose of ZnO NPs (0.2 mg/kg, 0.05 mg/kg) were investigated after intravenous exposure. In addition, 8-hydroxy-2'-deoxyguanosine (8-OHdG) was evaluated. Following the injection, ZnO NPs were rapidly removed from the blood and distributed to organs. Pulmonary emphysema was observed pathologically study in mice at 3 days after the 0.2 mg/kg dose and at 6 days after the 0.05 mg/kg dose. ZnO NPs were mainly accumulated in the lung and spleen within 60 min. From the long-term tissue distribution study, the liver showed peak concentration at 6 days, and spleen peaked at 1 day. The lungs kept high levels until 6 days. Tissue distribution and pathological study showed that the spleen, liver, and lungs are target organs for ZnO NPs. Accumulation in the liver and spleen may be due to the phagocytosis by macrophages. A dose-dependent increase in 8-OHdG was observed in mice treated with ZnO NPs. This study is the first to show information on kinetics and target organs following intravenous ZnO injection.

In the present study, we have extensively continued our previous investigations of the nonsynonymous single-nucleotide polymorphisms (SNPs) in the human DNase I (DNASE1) gene potentially relevant to systemic lupus erythematosus (SLE); therefore, all of the 58 nonsynonymous SNPs registered in the NCBI dbSNP database could be evaluated and it could be checked as to whether these SNPs might serve as a functional SNP. From a compiled expression analysis of the amino-acid-substituted DNase I corresponding to each of the SNPs, it was possible to sort them into 23 SNPs while not affecting the activity: 12 abolishing it, 14 reducing it, and 9 increasing it. Among a total of 58 nonsynonymous SNPs, only 4 SNPs exhibited genetic polymorphisms in some of the populations examined; a minor allele producing a loss-of-function variant of each SNP was not distributed in 14 different populations derived from three ethnic groups. It could be assumed that a minor allele of these functional SNPs, despite their remarkably low genetic heterogeneity, could directly serve as a genetic risk factor for SLE. Furthermore, among the human DNase family genes, it seems that DNASE1 is able to tolerate the generation of nonsynonymous SNPs, and that the amino-acid substitutions resulting from the SNPs in DNASE1 easily alter the activity.

Many nonsynonymous single-nucleotide polymorphisms (SNPs) in the human deoxyribonuclease I-like 1 (DNase 1L1) gene, possibly implicated in the blocking of endocytosis-mediated foreign gene transfer, have been identified, but only limited population data are available and no studies have evaluated whether such SNPs are functional. Genotyping of all 21 nonsynonymous human DNase 1L1 SNPs was performed in 16 different populations representing three ethnic groups using the PCR-restriction fragment length polymorphism technique. All of the nonsynonymous SNPs, except for SNP p.Val122Ile in Caucasian populations, exhibited a monoallelic distribution in all of the populations. On the basis of alterations in the activity levels resulting from the corresponding amino acid substitutions, two activity-abolishing and four activity-reducing SNPs were confirmed to be functional. Although all of the nonsynonymous SNPs that affected the catalytic activity showed extremely low genetic heterogeneity, it seems plausible that a minor allele of six SNPs producing a loss-of-function or extremely low-activity variant could serve directly as a genetic risk factor for diseases. Especially, the amino acid residues in activity-abolishing SNPs were conserved in animal DNases 1L1. Furthermore, results of phylogenetic analysis suggest that DNase 1L1 might have appeared latest among the DNase I family during the course of molecular evolution.

The objectives of this study were to evaluate all the non-synonymous single nucleotide polymorphisms (SNPs) in the DNase I and DNase I-like 3 (1L3) genes potentially implicated in autoimmune diseases as a functional SNP in terms of alteration of the activity levels. We examined the genotype distributions of the 32 and 20 non-synonymous SNPs in DNASE1 and DNASE1L3, respectively, in three ethnic groups, and the effect of these SNPs on the DNase activities. Among a total of 44 and 25 SNPs including those characterized in our previous studies [Yasuda et al., Int J Biochem Cell Biol42 (2010) 1216-1225; Ueki et al. Electrophoresis32 (2012) 1465-1472], only four and one, respectively, exhibited genetic heterozygosity in one or all of the ethnic groups examined. On the basis of alterations in the activity levels resulting from the corresponding amino acid substitutions, 11 activity-abolishing and 11 activity-reducing SNPs in DNASE1 and two activity-abolishing and five activity-reducing SNPs in DNASE1L3 were confirmed as a functional SNP. Phylogenetic analysis showed that all of the amino acid residues in activity-abolishing SNPs were completely or well conserved in animal DNase I and 1L3 proteins. Although almost all non-synonymous SNPs in both genes that affected the catalytic activity showed extremely low genetic heterogeneity, it seems plausible that a minor allele of 13 activity-abolishing SNPs producing a loss-of-function variant in both the DNase genes would be a direct genetic risk factor for autoimmune diseases. These findings may have clinical implications in relation to the prevalence of autoimmune diseases., (© 2013 FEBS.)

Many nonsynonymous SNPs in the human DNase II gene (DNASE2), potentially relevant to autoimmunity in conditions such as rheumatoid arthritis, have been identified, but only limited population data are available and no studies have evaluated whether such SNPs are functional. Genotyping of all the 15 nonsynonymous human DNase II SNPs was performed in three ethnic groups including 16 different populations using the PCR-restriction fragment length polymorphism technique. A series of constructs corresponding to each SNP was examined. Fifteen nonsynonymous SNPs in the gene, except for p.Val206Ile in a Korean population, exhibited a mono-allelic distribution in all of the populations. On the basis of alterations in the activity levels resulting from the corresponding amino acid substitutions, four activity-abolishing and five activity-reducing SNPs were confirmed to be functional. The amino acid residues in activity-abolishing SNPs were conserved in animal DNase II. All the nonsynonymous SNPs that affected the catalytic activity of human DNase II showed extremely low genetic heterogeneity. However, a minor allele of seven SNPs producing a loss-of-function or extremely low activity-harboring variant could serve as a genetic risk factor for autoimmune dysfunction. These functional SNPs in DNASE2 may have clinical implications in relation to the prevalence of autoimmune diseases., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Human Mpv17-like protein (M-LPH) has been suggested to play a role in mitochondrial function. In this study, we identified a RhitH (human regulator of heat-induced transcription) binding site in intron 1 of the M-LPH gene. Tissue distribution analysis showed that M-LPH was specifically distributed in tissues with high mitochondrial metabolism. Functional and genetic analyses of nonsynonymous single nucleotide polymorphisms (SNPs) in the RhitH gene revealed that p.Cys461Ser, p.Thr465Ala, and p.Leu495Gln, corresponding to substitutions in the zinc fingers, cause reductions in the repression activity that lead to upregulation of M-LPH expression. The analyses also showed that the minor allele frequencies of these SNPs are extremely low in worldwide populations.

We have focused on the 14 SNPs including all the non-synonymous and autoimmunity-related ones in the DNase II gene (DNASE2). The distribution of each allele and haplotype in these SNPs was examined in eight Asian, three African, three Mexican and two Caucasian populations using the newly developed PCR-RFLP methods. Eight SNPs among nine non-synonymous ones were monomorphic, indicating that a specific allele generating the intact activity-harboring DNase II in these SNPs is well conserved in worldwide populations. On the other hand, five other SNPs (-1951G>A, -1066G>C, -390A>C, +2630T>C, and +6235G>C) related to autoimmunity exhibited polymorphism common in worldwide populations, and especially their distributions were ethnic-dependent in the same manner as those of haplotypes. Furthermore, a strong linkage between SNPs -1951G>A and -1066G>C was confirmed in most populations. This study was the first to report any worldwide population analysis regarding all the non-synonymous and autoimmunity-related SNPs in the DNASE2, providing genetic information on the DNASE2 as a genetic marker for personal identification and/or genetic factor for susceptibility to autoimmunity., (Published by Elsevier Ireland Ltd.)

Several non-synonymous SNPs in the human deoxyribonuclease I-like 2 (DNase 1L2) gene responsible for DNA degradation during terminal differentiation of epidermal keratinocytes have been identified. However, only limited population data are available, and furthermore the effect of these SNPs on the DNase 1L2 activity remains unknown. Genotyping of all of the 17 SNPs was performed using the PCR-RFLP method in three ethnic groups including 14 different populations. A series of amino acid-substituted DNase 1L2 corresponding to each SNP was expressed, and its activity was measured. All of the six non-synonymous SNPs exhibited a mono-allelic distribution, whereas the distribution of some SNPs other than exonic ones was ethnicity-dependent. Each of the minor alleles in SNPs, p.Ala20Asp, p.Val104Leu, p.Asp197Ala, p.Glu274Lys and p.Asp287Asn, among the non-synonymous SNPs produced low or no activity-harbouring DNase 1L2. DNase 1L2 is well conserved, retaining full levels of enzymatic activity, with regard to these exonic SNPs in human populations. It seems plausible to assume that these SNPs affecting the activity may be one of the factors responsible for a genetic pre-disposition for failure of differentiation-associated cell death in various keratinocyte lineages, thereby leading to the development of parakeratosis. Our results may have clinical implications in relation to the pathogenesis of parakeratosis., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Five SNPs in the human DNase II gene have been reported to be associated with rheumatoid arthritis (RA). Genotype and haplotype analysis of 14 SNPs, nine SNPs of which reported in the NCBI dbSNP database in addition to these five SNPs, was performed in healthy subjects. The enzymatic activities of the amino acid substituted DNase II corresponding to each SNP and serum DNase II in healthy Japanese, and promoter activities derived from each haplotype of the RA-related SNPs were measured. Significant correlations between genotype in each RA-related SNP and enzymatic activity levels were found; alleles associated with RA exhibited a reduction in serum DNase II activity. Furthermore, the promoter activities of each reporter construct corresponding to predominant haplotypes in three SNPs in the promoter region of the gene exhibited significant correlation with levels of serum DNase II activity. These findings indicate these three SNPs could alter the promoter activity of DNASE2, leading to a decline in DNase II activity in the serum through gene expression. Since the three SNPs in the promoter region of the DNase II gene could affect in vivo DNase II activity through reduction of the promoter activity, it is feasible to identify these SNPs susceptible to RA., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Adult height is a highly heritable trait involving multiple genes. Recent genome-wide association studies have identified that SNP rs12338076 in the LHX3-QSOX2 locus, and rs1457595 and rs17032362 in the IGF1 locus are associated with human height in the Japanese population (Okada et al. (2010)). We performed a replication study to examine the associations between these three SNPs and adult height in the Japanese population based on autopsy cases. However, it was not possible to confirm that all these SNPs influenced adult height in the study population. We first conducted a wide-ranging survey of these three SNPs in the above genes using nine different populations including Asians, Africans and Caucasians, and demonstrated that the genotypes of rs12338076 and rs17032362 were distributed in an ethnicity-dependent manner; even within Asian populations, the genotype distributions of the SNPs differed widely. Although there are differences in height distribution between different populations, possibly due to genetic factors and/or gene-environmental interactions, the contradictory results of the association study and ethnic differences in genotype distribution allow us to assume that these height-related SNPs in the genes may contribute to adult height to a slight extent, at least in the Japanese population. It is anticipated that the present information will be useful for developing a reliable tool for personal identification through elucidation of the genetic basis of human height., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

ABO grouping of biological specimens is informative for identifying victims and narrowing down suspects. In Japan and elsewhere, ABO grouping as well as DNA profiling plays an essential role in crime investigations. In the present study, we developed a new method for ABO genotyping using allele-specific primers and real-time PCR. The method allows for the detection of three single nucleotide polymorphisms (SNPs) at nucleotide positions 261, 796, and 803 in the ABO gene and the determination of six major ABO genotypes. This method required less than 2 h for accurate ABO genotyping using 2.0 ng of DNA. This method could be applicable for rapid and simple screening of forensic samples., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Adult height is a highly heritable trait in that multiple genes are involved. Recent genome-wide association studies have identified a novel single-nucleotide polymorphism (SNP) rs1042725 in the high mobility group-A2 gene (HMGA2) and shown it to be associated with human height in Caucasian populations. We performed a replication study to examine the associations between SNPs in HMGA2 and adult height in the Japanese population based on autopsy cases. Although we could not confirm a significant association between rs1042725 in HMGA2 and adult height, another SNP, rs7968902, in the gene achieved significance for its association in the same populations, and the effect was the same as that documented previously. These findings permit us to conclude that the SNPs in HMGA2 are common variants influencing human height across different populations. Moreover, a worldwide population study of these SNPs using 14 different populations including Asians, Africans and Caucasians demonstrated that both haplotypes and genotypes for three height-related SNPs (rs1042725, rs7968682 and rs7968902) in HMGA2 were distributed in an ethnicity-dependent manner. This information will be useful for clarifying the genetic basis of human height., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Deoxyribonucleases (DNases) have been suggested to be implicated in the pathophysiology of autoimmune diseases. In the DNASE1L3 gene encoding human DNase I-like 3 (DNase 1L3), a member of the DNase I family, only two non-synonymous (R178 H and R206C) single nucleotide polymorphisms (SNPs) have been examined [Ueki et al., Clin. Chim. Acta 2009, 407, 20-24]. Three other non-synonymous (G82R, K96N, and I243M) and four synonymous (S17S, T84T, R92R, and A181A) SNPs, in addition to R206C and R178H, have been identified in DNASE1L3. We investigated the distribution of all these SNPs in exons of the gene in eight Asian, three African, and three Caucasian populations worldwide using newly devised genotyping methods. SNP T84T showed polymorphism in all the populations, and R92R was polymorphic in the three African and three Caucasian populations; R206C was distributed only in Caucasian populations. In contrast, no minor allele was found in five SNPs (S17S, G82R, K96N, A181A, and I243M) in DNASE1L3. Generally, the DNase 1L3 gene shows relatively low genetic diversity with regard to exonic SNPs. When the effect of amino acid/nucleotide substitutions resulting from the SNPs on DNase 1L3 activity was examined, none of the synonymous SNPs had any effect on the DNase 1L3 activity, whereas among non-synonymous SNPs, SNP G82R diminished the activity of the enzyme, being similar to R206C. These findings permit us to assume that, although only R206 exhibits polymorphisms in a Caucasian-specific manner, at least SNPs G82R and R206C in DNASE1L3 might be potential risk factors for autoimmune disease., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Identification of the population origin of an individual is very useful for crime investigators who need to narrow down a suspect based on specimens left at a crime scene. Single nucleotide polymorphisms of the Y chromosome (Y-SNPs) are a class of markers of interest to forensic investigators because many of the markers indicate regional specificity, thus providing useful information about the geographic origin of a subject. We selected seven informative Y-SNPs (M168, M130, JST021355, M96, P126, P196, and P234) to differentiate the three major population groups (East Asian, European, and African) and used them to develop forensic application. SNP genotyping was carried out by multiplex PCR reaction and multiplex single base extension (MSBE) reaction followed by capillary electrophoresis of extension products. This method can be used to assign a haplogroup from both degraded male DNA samples and DNA samples containing a mixture of female and male DNA through PCR primers that generate small amplicons (less than about 150 bp) and are highly specific for targets on the Y chromosome. The allelic state of each marker was definitively determined from a total of 791 males from the three major population groups. As expected, samples from the three major population groups showed Y-haplogroups common in the region of provenance: Y haplogroups C, D, and O for East Asians; IJ and R1 for Europeans; and AB and E for Africans., (Published by Elsevier Ireland Ltd.)

The single-nucleotide polymorphisms (SNPs) in the human DNase I gene (DNASE1) might be involved in susceptibility to some common diseases; however, only limited population data are available. Further, the effects of these SNPs on in vivo DNase I activity remain unknown. The genotype and haplotype of all the SNPs in DNASE1 were determined in 3 ethnic groups including 14 populations using newly developed methods. Together with our previous data on the nonsynonymous SNPs, two major haplotypes based on the five exonic SNPs were identified; genetic diversity in the Asian population was low. Among 10 SNPs, other than exonic SNPs in the gene, only 3 were polymorphic among all the populations. Haplotype distribution, based on all the polymorphic SNPs, was clarified to be generally varied in an ethnic-dependent manner. Thus, the genetic aspects of DNASE1 with regard to all the SNPs in wide-ranging ethnic groups could be first demonstrated. Further, there was no correlation of all the polymorphic SNPs other than nonsynonymous ones with serum DNase I activity levels. Polymorphic SNPs other than the exonic SNPs might not be directly related to common diseases through alterations in in vivo levels of the activity.

Three polymorphisms, Paraoxonase 1 (PON1) Q192R (C/G), endothelial nitric oxide synthase (eNOS) E298D (G/T) and eNOS T-786C have been suggested to be potentially associated with coronary artery spasm in Japanese patients. Data on worldwide populations are needed to clarify whether these associations could hold true for other populations. However, few data are available especially in Africans, spasm of which has been suggested to be an aetiology of myocardial infarction. Therefore, these polymorphisms were investigated in three Africans, Ovambos (n = 123), Ghanians (n = 118) and Xhosas (n = 96), together with Japanese (n = 96), by using polymerase chain reaction-restriction fragment length polymorphism analysis. Genotype-distributions of all these SNPs in African populations were significantly different from those in Caucasians, whereas were similar to those in Japanese population. African populations exhibit relatively higher frequency of spasm-associated G192 allele in PON1 Q192R being similar to Japanese population, however frequencies of spasm-associated T298 allele and -C786 allele in SNP eNOS E298D and T-786C, respectively, were conversely lower in Africans than Caucasians. Although healthy subjects have been recruited in this study, these findings may provide genetic background for elucidation of aetiology of spasm., (Copyright © 2011 John Wiley & Sons, Ltd.)

Several SNPs in the deoxyribonuclease I-like 1 (DNase 1L1) and DNase 1L2 were investigated. In the present study, the genotype distributions of three synonymous SNPs (V59V, rs1050095; P67P, rs1130929; A277A, rs17849495) in the DNase 1L1 gene and four non-synonymous SNPs, V122I (rs34952165), Q170H (rs6643670), and D227A (rs5987256) in the DNase 1L1 gene, as well as D197A (rs62621282) in the DNase 1L2 gene were investigated in 13 populations. In all the populations, no variation was found in four SNPs (V59V, Q170H, D227A, and A277A) in DNASE1L1 or in D197A in DNASE1L2. As for V122I, only the German population showed a low degree of polymorphism. The SNP V122I in DNASE1L1 was monoallelic for the G-allele in all of the Asian and African populations examined, with no polymorphism being evident. Since the A-allele in SNP V122I was distributed in only the Caucasian populations, not in the other ethnic groups, it was confirmed that the A-allele in SNP V122I was Caucasian-specific. On the other hand, only P67P in DNASE1L1 was polymorphic among three synonymous SNPs. The effect of nucleotide substitution corresponding to polymorphic SNP P67P on DNase 1L1 activity was examined: the corresponding nucleotide substitution in polymorphic SNP P67P has little effect on the DNase activity.

A reduction of deoxyribonuclease I (DNase I) activity levels in the serum of patients with autoimmune diseases has been reported. The objectives of this study were to clarify genetic and biochemical aspects of 12 non-synonymous SNPs in the human gene (DNASE1), potentially giving rise to an alteration in the in vivo DNase I activity levels. Genotyping of all the non-synonymous SNPs was performed in healthy subjects of three ethnic groups including 15 populations using newly developed methods. Among them, only four SNPs, R-21S, Y95S, G105R, and Q222R were polymorphic in all or some populations; Asian group showed a relatively low genetic diversity of these SNPs. Furthermore, the distribution pattern of the common SNP Q222R was classified into three ethnic groups. The activity levels of the amino acid-substituted DNase I forms derived from SNPs R-21S, G105R, P132A, and P197S were significantly high compared with that of the wild-type; the polymorphic SNPs R-21S and G105R gave rise to a high activity-harboring DNase I isoform. On the other hand, activity levels from Q35H, R85G, V89M, C209Y, Q222R, and A224P were significantly low, but these SNPs, except Q222R, were not distributed in any of the populations. However, since these SNPs may produce potentially low levels of in vivo DNase I activity, a minor allele in each SNP will be served as a genetic risk factor for autoimmune diseases. These findings on non-synonymous SNPs in DNASE1 may provide a biochemical-genetic basis for the clarification of a possible relationship between DNase I and the diseases., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Members of the human DNase I family, DNase I-like 1 and 2 (DNases 1L1 and 1L2), with physiological role(s) other than those of DNase I, possess three and one non-synonymous SNPs in the genes, respectively. However, only limited population data are available, and the effect of these SNPs on the catalytic activity of the enzyme remains unknown. Genotyping of all the non-synonymous SNPs was performed in three ethnic groups including six different populations using the PCR-RFLP method newly developed. Asian and African groups including Japanese, Koreans, Ghanaians and Ovambos were typed as a single genotype at each SNP, but polymorphism at only SNP V122I in DNase 1L1 was found in Caucasian groups including Germans and Turks; thus a Caucasian-specific allele was identified. The DNase 1L1 and 1L2 genes show relatively low genetic diversity with regard to these non-synonymous SNPs. The level of activity derived from the V122I, Q170H and D227A substituted DNase 1L1 corresponding to SNPs was similar to that of the wild-type, whereas replacement of the Asp residue at position 197 in the DNase 1L2 protein with Ala, corresponding to SNP D197A, reduced its activity greatly. Thus, SNP V122I in DNase 1L1 exhibiting polymorphism exerts no effect on the catalytic activity, and furthermore SNP D197A in DNase 1L2, affecting its catalytic activity, shows no polymorphism. These findings permit us to postulate that the non-synonymous SNPs identified in the DNase 1L1 and 1L2 genes may exert no influence on the activity levels of DNases 1L1 and 1L2 in human populations.

Background: Several non-synonymous SNPs in the human DNase II gene, potentially relevant to autoimmunity, have been identified, but only limited population data are available. Also, the effects of these SNPs on the catalytic activity of the enzyme remain unknown., Methods: Genotyping of all the non-synonymous SNPs was performed in healthy subjects of 3 ethnic groups including 6 different populations using the PCR-RFLP technique. A series of mutants corresponding to each SNP was expressed in COS-7 cells and its activity was measured., Results: Five of the populations, including Japanese, Germans, Turks, Ghanaians and Ovambos, were typed as a single genotype at each SNP, but Koreans were not. Constructs derived from minor alleles at A58del, V284M, R298L and Q322Term exhibited drastically low or almost no activity., Conclusion: The DNase II gene shows relatively low genetic diversity with regard to these non-synonymous SNPs, suggesting that the enzyme has been well conserved. A minor allele at V284M is distributed with a frequency of 0.013 in the database, and it seems plausible that levels of DNase II activity for the heterozygote are lower than those in individuals with the predominant homozygote. Our results may have clinical implications in relation to the prevalence of autoimmune diseases.

Delta-aminolevulinic acid dehydratase (ALAD) is a cytosolic enzyme in the heme biosynthetic pathway. The ALAD is controlled by two codominant alleles (ALAD1 and ALAD2), which result in a Asn-Lys substitution at amino acid position 59 of the mature enzyme based on a single nucleotide polymorphism (SNP) (G177C) leading three phenotypes (ALAD1-1, ALAD1-2, and ALAD2-2). Previous studies have shown that this polymorphism is related to lead toxicity. There is little evidence showing interethnic differences in the distribution of this polymorphism. We examined the distribution of genetic variants of the ALAD G177C polymorphism in four Asians, three Africans, and three Mexicans. Genomic DNA was extracted from blood or bloodstain, and the genotypes for the ALAD polymorphism were determined by PCR followed by RFLP digestion and gel electrophoresis. We found a notable interethnic disparity in the distribution of ALAD G177C genotypes and alleles. The frequencies of ALAD2 in Asian populations were comparable to those in Caucasians, while Africans had no mutation allele. These findings may help us understand the interethnic disparities in susceptibility to lead toxicity.