[Related factors associated with the birth of children with down syndrome]

Down syndrome is a genetic disorder due to trisomy of 21 chromosome, which mainly is manifested by moderate to severe mental problems, including physical, sensory and motor symptoms. This study was done to determine the related factors associated with the birth of children with Down syndrome. This cross-sectional study was carried out on 913 mothers with children or fetuses of Down syndrome who were referred to genetic counseling clinics in Tehran, Iran during 2011. Diagnosis of Down syndrome confirmed by the chromosomes culture. Maternal age, maternal age at menarche, parents interfamilial marriage, maternal blood group, the number of abortions and children, collected through the questionnaires. Out of 913 affected children and fetuses with Down syndrome, 420 [46%] and 493 [54%] were female and males respectively. 1.17 considered to be The male/female ratio. 32.4% of mothers were in 25-30 years of age and 42% of parants had interfamilial marriages. The abortion in mothers varied from lack of ahortion [96.7%] up to 5 repetitive abortion [0.1%]. The number of children in families with affected subject consisted of 1 [15.1%], 4 [16.5%] and 11-13 [1.3%]. This study showed that Down syndrome infants are mostly born with the mothers of 25-30 years age

Aflatoxins in Iran: nature, hazards and carcinogenicity

Many studies have shown that mycotoxin contamination of agricultural products is a challenge for individual's health especially in developing countries. Improper production and storage of foods, prepare conditions for aflatoxin production in crops, especially rice, wheat, pistachio, walnut, almond, etc which are the main sources of foods for people. Feeding livestock by contaminated bread is another way of human exposure to mycotoxins, especially aflatoxin and because of expensive methods for detecting and analyzing aflatoxin in laboratory; it is not measured in foods. This manuscript is a review of some Iranian and nonIranian reports about aflatoxin, its exposure ways, its adverse effect on human health and nutrition, as well as methods for reducing its exposure. Based on studies on foods, aflatoxin exposure is high in Iran. Since livestock feeding by contaminated bread is one of the potential ways for milk contamination, we should control and reduce aflatoxin contamination by improving production process, storage condition and livestock feeding as soon as possible. Pistachio is one of the most important exporting products of Iran and to maintain Iran's position in exporting of this product, specific regulations on lowering its contamination with aflatoxin should be considered seriously. Finally, effective controlling of all food and feedstuffs which are vulnerable to aflatoxin contamination is necessary to prevent its effects

Genetic doping and health damages

Use of genetic doping or gene transfer technology will be the newest and the lethal method of doping in future and have some unpleasant consequences for sports, athletes, and outcomes of competitions. The World Anti-Doping Agency [WADA] defines genetic doping as "the non-therapeutic use of genes, genetic elements, and/or cells that have the capacity to enhance athletic performance". The purpose of this review is to consider genetic doping, health damages and risks of new genes if delivered in athletes. This review, which is carried out by reviewing relevant publications, is primarily based on the journals available in GOOGLE, ELSEVIER, PUBMED in fields of genetic technology, and health using a combination of keywords [e.g., genetic doping, genes, exercise, performance, athletes] until July 2010. There are several genes related to sport performance and if they are used, they will have health risks and sever damages such as cancer, autoimmunization, and heart attack

Iranian Azeri's Y-chromosomal diversity in the context of turkish-speaking populations of the Middle East

The main goal of this study was to conduct a comparative population genetic study of Turkish speaking Iranian Azeries as being the biggest ethno-linguistic community, based on the polymorph markers on Y chromosome. One hundred Turkish-speaking Azeri males from north-west Iran [Tabriz, 2008-2009] were selected based on living 3 generations paternally in the same region and not having any relationship with each other. Samples were collected by mouth swabs, DNA extracted and multiplex PCR done, then 12 Single Nucleotide Polymorphisms [SNPs] and 6 Microsatellites [MS] were sequenced. Obtained data were statistically analyzed by Arlequin software. SNPs and Microsatellites typing were compared with neighboring Turkish-speaking populations [from Turkey and Azerbaijan] and Turkmens representing a possible source group who imposed the Turkish language during 11-15[th] centuries AD. Azeris demonstrated high level of gene diversity compatible with patterns registered in the neighboring Turkish-speaking populations, whereas the Turkmens displayed significantly lower level of genetic variation. This rate of genetic affiliation depends primarily on the geographic proximity. The imposition of Turkish language to this region was realized predominantly by the process of elite dominance, i.e. by the limited number of invaders who left only weak patrilineal genetic trace in modern populations of the region

Genetic linkage analysis of 15 DFNB loci in a group of Iranian families with autosomal recessive hearing loss

Hearing loss [HL] is the most frequent sensory birth defect in humans. Autosomal recessive non-syndromic HL [ARNSHL] is the most common type of hereditary HL. It is extremely heterogeneous and over 70 loci [known as DFNB] have been identified. This study was launched to determine the relative contribution of more frequent loci in a cohort of ARNSHL families. Thirty-seven Iranian families including 36 ARNSHL families and 1 family with Pendred syndrome each with >/= 4 affected individuals, from seven provinces of Iran, were ascertained. DFNB1 contribution was initially studied by DNA sequencing of GJB2 and linkage analysis using the relative STR markers. The excluded families were then subjected to homozygosity mapping for fifteen ARNSHL loci. Sixteen families were found to be linked to seven different known loci, including DFNB1 [6 families], DFNB4 [3 families +1 family with Pendred syndrome], DFNB63 [2 families], DFNB2 [1 family], DFNB7/11 [1 family], DFNB9 [1 family] and DFNB21 [1 family]. DNA sequencing of the corresponding genes is in progress to identify the pathogenic mutations. The genetic causes were clarified in 43.2% of the studied families, giving an overview of the causes of ARNSHL in Iran. DFNB4 is ranked second after DFNB1 in the studied cohort. More genetic and epigenetic investigations will have to be done to reveal the causes in the remaining families

Nutrigenomics and nutrigenetics

The nutrients are able to interact with molecular mechanisms and modulate the physiological functions in the body. The Nutritional Genomics focuses on the interaction between bioactive food components and the genome, which includes Nutrigenetics and Nutrigenomics. The influence of nutrients of f genes expression is called Nutrigenomics, while the heterogeneous response of gene variants to nutrients, dietary components and developing nutraceticals is called nutrigenetics. Genetic variation is know to affect food tolerances among human subpopulations and may also influence dietary requirements and raising the possibility of individualizing nutritional intake for optimal health and disease prevention on the basis of an individual's genome. Nutrigenomics provides a genetic understanding for how common dietary components affect the balance between health and disease by altering the expression and/or structure of an individual's genetic makeup. Nutrigenetics describes that the genetic profile have impact on the response of body of bioactive food components by influencing their absorption, metabolism, and site of action. In this way, considering different aspects of gene-nutrient interaction and designing appropriate diet for every specific genotype that optimize individual health, diagnosis and nutritional treatment of genome instability, we could prevent and control conversion of healthy phenotype to diseases

Gene and aging

Collection of multiple processes that increase the chronological age of an organism leading to death is defined as aging, and even though important, it is poorly understood. Recent research has shown that aging is due to biochemical and genetic changes, in interaction with environmental effects, including diet and nutrition. Most knowledge on aging is based on genetic model system, but its molecular mechanisms are still not very clear. Discoveries in molecular biology have made way to look for candidate genes influencing lifespan. Furthermore, new investigations have stressed on the roles of mitochondria as the major generators and direct targets of reactive oxygen species. This paper reviews some recent literature on genes and aging in model system, then discusses the role of mitochondria and nutrients in human aging

Molecular pathology of 6 novel GJB2 allelic variants detected in familial and sporadic Iranian non syndromic hearing loss cases

Mutations of GJB2 gene encoding connexion 26 are the most common cause of hearing loss in many populations. A very wide spectrum of GJB2 gene mutations associated with hearing loss have been detected but pathogenic role has been tested only for a part of them. In this study, we have provided genetic evidence on the pathogenicity of our previously reported novel GJB2 allelic variants. The pathogenic role of GJB2 allelic variants were assessed using co segregation of each allelic variant with hearing loss in family members, absence of the allelic variants in control populations, coexistence with a second GJB2 mutation, nature of the amino acid substitution and evolutionary conservation of the appropriate amino acid. The GJB2 allelic variants including 363delC, 327delGGinsA, H16R and G200R have been co segregated with autosomal recessive non syndromic hearing loss in five families and are not found in control subjects. The G130V and K102Q were found in heterozygous state in two deaf individuals. G130V results in an exchange a residue highly conserved among all the connexins but was found with a rate of 1% in control subjects and K102Q results in an exchange a residue not conserved among all the connexins and not identified in control subjects. We conclude that, 363delC, 327delGGinsA, H16R and G200R may be pathogenic. However, the pathogenicity and inheritance of K102Q and G130V can not be assessed clearly and remains to be identified

Prevalence of orofacial complications in Iranian patients with beta thalassemia major

Major beta-thalassemia is the most common monogenic known disorder in Iran and about 15000 persons are affected. The purpose of this study was to evaluate the prevalence of orofacial complications. In this cross-sectional study during 2003-2004, 300 patients with major beta -thalassemia referring to 8 hospitals for routine examinations, blood infusion and treatment in cities of Tehran, Isfahan, Sari, Zahedan, Shahre Kord and Sanandag were studied. The questionnaires included general information, medical and dental history. The prevalence of orofacial complications in major beta-thalassemia was: saddle nose [67%], maxillary protrusion [49/7%], color change of oral mucosa [41/7%], rodent face [34/7%], deep bite [21/7%], spacing [20/7%], and open bite [8/7%], respectively. There was not any relationship between the complications and sex. Most of the patients [91%] were in the first and second decade of life. Early diagnosis and blood infusion caused less prevalence of rodent face. The most observed type of occlusion was class 1, 2 and 3, respectively. Knowing the prevalence of complication can help the dentists to do properly for these patients to solve their problems and improve knowledge of the parents about their children's dental health

Familial and sporadic GJB2-related deafness in Iran: review of gene mutations

Mutations in the GJB2 gene encoding connexin 26 protein, are the main cause for autosomal recessive and sporadic non syndromic hearing loss in many populations. Here, we have taken together and reviewed results from our six previous publications, our unpublished data from ten Iranian provinces, as well as data from two previous mutation reports to provide a comprehensive collection of data for GJB2 mutations and deafness in Iran. In all, 1095 hearing impaired students and their deaf siblings from 890 families in 10 provinces of Iran were studied. The prevalence and type of the GJB2 gene mutations were investigated using nested PCR pre screening strategy and direct sequencing of the coding exon of the gene. Altogether 31 different genetic variants were detected from which 17 GJB2 mutations were identified. GJB2 mutations were found in 14.6% of deaf families [18.29% of familial and 12.7% of sporadic cases]. We found GJB2 mutations in both alleles in 78% of GJB2 mutations chromosomes. However, 35delG mutation was the most common GJB2 mutation accounting for 74.5% of the mutations in populations studied. Our data indicated that a specific combination of GJB2 mutations types and frequencies was presented in different populations of Iran. These results also highlight the importance of GJB2 mutations in development of hearing loss in familial and sporadic deaf families in different parts of the country and can be used as a basis of genetic counseling and clinical guideline in Iran

Autosomal recessive and sporadic non syndromic hearing loss and the incidence of Cx26 mutations in a Province of Iran

Despite the enormous heterogeneity of genetic hearing loss, mutations in the GJB2 [connexin 26] gene located on 'DFNB1' locus [13q12] account for up to 50% of cases of autosomal recessive non-syndromic hearing loss [ARNSHL] in some populations. This study describes the analysis of 100 autosomal recessive and sporadic nonsyndromic hearing loss individuals from 79 families each having at least one deaf child in Chehar Mahal va Bakhtiari province in west of Iran. We have investigated the prevalence of the connexin 26 gene mutations using nested PCR strategy to screen the predominant 35delG mutation and subsequent direct sequencing to detect other Cx26 mutations. Seven different genetic variants were detected from which one novel variant was including 363delC. The 35delG was the most common mutation found in 5 of 79 families [6.3%]. Cx26 related deafness mutations [35delG, [V27I; E114G]] and R127H] were found in 12 of 158 chromosomes studied [7.8%]. We conclude that the association of Cx26 mutations with deafness in Chehar Mahal va Bakhtiari province is low and looks like most other populations of Iran

investigation of human apolipoprotein e polymorphisms in multiple sclerosis patients of Iran

Multiple sclerosis [MS] is a chronic inflammatory disorder of the central nervous system, with a complex etiology that includes a strong genetic component. The chromosome 19q13 region surrounding the apolipoprotein E [APOE] gene has shown consistent evidence of involvement in MS. In a cross-sectional study, to show the APOE genotype and allele frequency in the MS population of Iran in comparison with the control group, we genotyped its polymorphisms [sigma 2, sigma 3 and sigma 4 alleles]. The authors investigated 81 patients with clinically definite MS and 93 asymptomatic elderly volunteers. The frequency of the APOE allele in the MS population in comparison with controls was 9.3% vs. 0.5% for sigma 4, 44.4% vs. 51.6% for sigma 3, and 46.3% vs. 47.8% for sigma 2. The highest frequency of APOE genotype was from sigma 2/sigma 3 with 66.7% vs. 94.6% and the lowest, sigma 4/sigma 4 genotype with 2.5% vs. 0%. The authors found significant differences in the distribution of 84 allele between patients with MS and controls [9.3% vs. 0.5%; X[2]=15.2;df=2; p<0.001]. The highest frequency of sigma 4 allele in MS patients was in Pure Turkish [25.0% vs. 5.3%] ethnicity. There was no significant relation between ethnicity and genotype. In the present study sigma 2/sigma 4, sigma 3/sigma 4 and sigma 4/sigma 4 genotypes were more common in bout-onset cases compared to primary progressive cases, and the secondary progressive disease was higher in carriers of sigma 4 allele. Also, the sigma 2 allele was higher in relapsing remitting disease

Frequency of genetic polymorphism of the gene encoding 16kDa clara cell secretory protein [CC16] in Shiraz, Iran

The Clara cell protein [CC16] is a small and readily diffusible protein of 16 kDa secreted by bronchiolar Clara cells in the distal airspaces. Mutation detection methods identified an adenine to guanine substitution in the CC16 gene at position 38 [A38G] downstream from the transcription initiation site within the non-coding region of exon 1. In the present study, the genetic polymorphism of CC16 was detected by PCR-based method in 175 normal individuals from Shiraz population, Fars province [south of Iran]. Initially the subjects were divided into two sex groups. Considering that there was no statistically significant differences between males and females [?2 = 5.52; df = 2; P<0.05] the sex groups were pooled. The frequencies of 38A and 38G alleles were 0.24 and 0.76 percent, respectively. The study population was at Hardy-Weinberg equilibrium [?2 = 2.61; df = 1; P<0.05]. The present results indicated that this polymorphism might have a geographic distribution

Report of a new mutation and frequency of connexin 26 gene [GJB2] mutations in patients from three provinces of Iran

Autosomal recessive and sporadic non-syndromic hearing loss [ARSNSHL] is the major form of hereditary deafness.Mutations in the GJB2 gene encoding the gap-junction protein Connexin 26 have been identified to be highly associated with ARSNSHL. In this study we have analyzed 196 deaf subjects from 179 families having one or more deaf children in 3 proviences of Iran, including Kordestan, Khuzestan and Golestan. The nested PCR prescreening strategy and direct sequencing technique were used to detect the mutations in coding exon of the gene. Altogether 3 GJB2 recessive mutations including 35delG, 167delT and V27I+E114G, were identified in 23 of 179 families [12.8%]. Fourteen of 179 families were observed to have GJB2 mutation in both alleles [7.8%]. A novel variant [R159H] also was found in a deaf family from Khuzestan. Four polymorphisms V27I, E114G, S86T and V153 I also were detected in 7 families. A polymorphism [S86T] was seen in the whole population studied. Our data indicated that the rate of connexin 26 mutations is different in this three Irainian population and is lower than the high frequency of 35delG [26%] reported from Gilan province in the north of Iran

Epidemiological study of T4, T3 and TSH mean concentrations in four Iranian populations

T4 and T3, two major hormones of thyroid gland, are responsible for regulation of "basal metabolism" in the body. Thyroid function is regulated primarily by variation in the pituitary TSH. In this study, about four hundred individuals were considered from four Iranian populations. They were selected randomly in their cities; Shiraz, Mashhad, Rasht, and Ilam. Essential family information was asked to achieve native belonging of each person to related population. Blood specimens were collected, by separating serums, freezed serums were transferred immediately to Tehran for hormone assay. Assay of T4 and T3 concentrations was carried out by 'RIA-magnetic' kits and of TSH by 'IRMA-magnetic' kits. Analysis of variance has been taken into account among days of sampling in each city to calculate mean concentrations for T4, T3 and TSH. Analysis of association between age and hormones concentrations in each population was done by the regression and the correlation tests. Significant differences were detected at T4 mean concentration in each of these populations [P=0.0001]. Differences for T3 mean concentration were observed only between Shiraz and Mashhad [P=0.021]; and Shiraz and Rasht [P=0.003]. By increasing age of individuals, there were also a negative correlation at mean concentrations of T4 and T3 in Ilam [P=0.022], and Mashhad [P=0.016] respectively. According to these data, and specificity of environmental and genetic factors to each popualtions, specific 'normal reference' of T4 and T3 homones should be considred for each of these populations. Correlation study of mean concentrations of these hormones and genetic variations of some critical genes such as thyroid peroxidase [TPO] and iodothyronine deiodinase can open new window of epidimiology among Iranian popualltions

Molecular detection of prostate specific antigen in patients with prostate cancer or benign prostae hyperplasia the first investigation from Iran

Prostate cancer is the second common form of cancer in men. Detection of circulating Prostate Specific Antigen [PSA] transcripts has effectively been used for early diagnosis of prostate cancer cells. This investigation employed a reverse transcriptase polymerase chain reaction [RT-PCR] technique to distinguish the patients with either localized or metastatic prostate cancer [CaP] vs. Benign Prostate Hyperplasia [BPH] and control subjects, as compared with clinical and pathological records. With reservation of ethical issues, blood samples were collected from 60 cases. Based on pathological and clinical findings, 25 patients [20 with localized cancer, 5 with metastatic], 22 with BPH, and 13 healthy [including 3 females] subjects as negative controls, were selected from Shariati, Mehrad, Sina,, Khatam and Atie Hospitals in Tehran, Iran. RT-PCR for a 260 bp PSA transcript was then performed. Clinical and pathological records were used for the assessment and comparison of PSA RT-PCR results. None of the control subjects and BPH [with 7 exceptions] were found positive by RT-PCR [Relative specificity= 72.7%]. In patients with prostate cancer, 21 out of 25 were found PSA positive [Relative sensitivity=83.4%] and the remaining 3 have been shown to be PSA negative [Positive predictive value= 83.4%]. All of 5 metastatic patients [100%] revealed PSA positive results. Our data reflects the clinical relevance and significance of RT-PCR results as assessed with clinical and pathological examinations. PSA RT-PCR might be used as a powerful means for diagnosis, even when either pathological or clinical findings are negative, and could be employed for further molecular epidemiology surveys

Dermatoglyphics in patients with oligo/ azospermia

The study of patterns of fingerprints is important in anthropology and medical genetics, chiefly because of their diagnostic usefulness. In the present work, we studied the frequencies of various types of skin ridges of the first phalanx in patients with sever oligospermia or azospermia. In a double-blind case-control study, we determined the frequencies of fingerprints in 880 first phalanxes belonging to 48 men with sever oligospermia and 40 men with azospermia. We determined the types of fingerprints based on Galton classification. Also their FRC, TFRC and AFRC were calculated. Then the results were compared with each other and general population as control group. The most frequent type of fingerprint in both case groups was "Loop". Frequencies of different types among two groups of cases were statistically different [P<0.005]. Also they were statistically different with general population [P<0.005]. The largest mean of FRC in men with oligospermia was belonging to the left ring fingers [23.1] and the second to the right thumbs [21.91]. The largest mean of FRC in men with azospermia was belonging to the right thumbs [23.6] and the second to the right ring fingers [22.6]. The mean of TFRCs in men with oligosoermia and azospermia were 106.8 and 114.39, respectively, and the mean of AFRCs in those two groups were 14 and 11, respectively; their differences were not statistically significant. It can be concluded that qualitative feathers of the fingerprints of men with oligospermia and azospermia were different with each other and with general population. And quantitative feathers of the fingerprints in those two case groups were statistically different as well

Molecular investigation of Leber's hereditary optic neuropathy common mutation in suspected patients

LHON is a mitochondrial neurodegenerative disorder often manifesting itself in the second or third decade of life, and hence resulting in progressive central vision loss sually in a short period of 2-8 weeks within which different degrees of blindness may occur. Etiologically, more than twenty missense mutations have been reported for LHON, amongst which the three mutations of G11778A, G3460A and T14484C, affecting NADH dehydrogenase complex activity, are recognized as primary mutations. The three primary mutations account for 90% of LHON patients, emphasizing the importance of molecular investigation of these mutations for differential diagnosis of LHON. Using PCR-RFLP, this research resulted in the detection of two LHON families carrying the G11778A mutation in homoplasmy and described the clinical and molecular features of the disease in the patients

Frequency of a very rare 35delG mutation in two ethnic groups of iranian population

The 35delG mutation in the Connexin 26 gene [Cx26], at the DNFB1 locus is the most common mutation in the patients with autosomal recessive non-syndromic hearing loss [ARNSHL]. We have studied a total of 224 deaf cases from 189 families in two populations of Iran [Sistan va Bluchestan and Hormozgan provinces] by prescreening nested PCR, polyacrylamide gel electrophoresis and consequent direct sequencing method for all cases. The aim of the present work was to find prevalence of GJB2 mutations in the populations studied. Four different GJB2 mutations including 35delG, W24X, R127H and [V27I + E114 G] were identified in 11 of 189 families [5.8%]. Two polymorphisms [V27I and V153I] also were detected in 14 families. A polymorphism S86T was determined in all cases. Homozygote 35delG mutation was found only in 1 of 189 families [0.5%].The rate of Cx26 mutations found in this study was lower than other Iranian populations. So the cause of deafness in the populations studied remains to be detected in other loci or genes

Aging coefficient in different religious groups in Iran

Aging Coefficient [AC], or aged'child ratio, is the number of individuals aged 65 years and over, divided by the number of individuals aged 0-14, multiplied by 100. In this point'descriptive study, the aging coefficient has been calculated for the followers of four different religions, for the past four respective decades, according to sex and locality. Overall age composition in different religious groups, in a decreasing order is: Christians, Jews, and Zoroastrians showed a slight decrease in the 80's and a higher increase afterward. Moslems show a more consistent mode, but with a slight increase in the last decade; but in all cases AC has been lower than 15, presenting a higher proportion of a young population or lower aged group. The increase of AC in each group can be caused by the old age survival, i.e. increasing life expectancy, or decreasing birth rate