Vitamin D receptor gene polymorphisms and haplotypes (Apa I, Bsm I, Fok I, Taq I) in Turkish psoriasis patients.

BACKGROUND: Psoriasis is an inflammatory disease characterized by increased squamous cell proliferation and impaired differentiation. Vitamin D, Calcitriol, and its analogues are successfully used for psoriasis therapy. However, it is unknown why some psoriasis patients are resistant to Vitamin D therapy. Vitamin D mediates its activity by a nuclear receptor. It is suggested that polymorphisms and haplotypes in the VDR gene may explain the differences in response to vitamin D therapy. MATERIAL/METHODS: In this study, 102 psoriasis patients and 102 healthy controls were studied for VDR gene polymorphisms. The Fok I, Bsm I, Apa I and Taq I polymorphisms were examined by PCR-RFLP, and 50 subjects received vitamin D therapy to evaluate the association between VDR gene polymorphisms and response to vitamin D therapy. Existence of cutting site is shown by capital letters, and lack was shown by lower case. The haplotypes were analysed by CHAPLIN. RESULTS: There was significant difference in allele frequency of T and genotype frequency of Tt between cases and controls (p values 0.038 and 0.04, respectively). The Aa and bb genotypes were significantly higher in early onset than late onset psoriasis (p values 0.008 and 0.04, respectively). The genotypes Ff, ff and TT are significantly different between vitamin D3 therapy responders and non-responders (p values 0.04, 0.0001, 0.009, respectively). To the best of our knowledge, this is the first report showing importance of VDR gene haplotypes in psoriasis, the significance of the Wald and LR (Likelihood Ratio) statistics (p=0,0042) suggest that FfBbAatt is a disease-susceptibility haplotype. CONCLUSIONS: Haplotype analysis is a recent and commonly used method in genetic association studies. Our results reveal a previously unidentified susceptibility haplotype and indicate that certain haplotypes are important in the resistance to vitamin D3 therapy and the onset of psoriasis. The haplotypes can give valuable data where genotypes unable to do.

TRAIL death receptor-4, decoy receptor-1 and decoy receptor-2 expression on CD8+ T cells correlate with the disease severity in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid Arthritis (RA) is a chronic autoimmune inflammatory disorder. Although the pathogenesis of disease is unclear, it is well known that T cells play a major role in both development and perpetuation of RA through activating macrophages and B cells. Since the lack of TNF-Related Apoptosis Inducing Ligand (TRAIL) expression resulted in defective thymocyte apoptosis leading to an autoimmune disease, we explored evidence for alterations in TRAIL/TRAIL receptor expression on peripheral T lymphocytes in the molecular mechanism of RA development. METHODS: The expression of TRAIL/TRAIL receptors on T cells in 20 RA patients and 12 control individuals were analyzed using flow cytometry. The correlation of TRAIL and its receptor expression profile was compared with clinical RA parameters (RA activity scored as per DAS28) using Spearman Rho Analysis. RESULTS: While no change was detected in the ratio of CD4+ to CD8+ T cells between controls and RA patient groups, upregulation of TRAIL and its receptors (both death and decoy) was detected on both CD4+ and CD8+ T cells in RA patients compared to control individuals. Death Receptor-4 (DR4) and the decoy receptors DcR1 and DcR2 on CD8+ T cells, but not on CD4+ T cells, were positively correlated with patients' DAS scores. CONCLUSIONS: Our data suggest that TRAIL/TRAIL receptor expression profiles on T cells might be important in revelation of RA pathogenesis.

No strong association between HER-2/neu protein overexpression and gene amplification in high-grade invasive urothelial carcinomas.

The generation of urothelial carcinoma is caused by the accumulation of various molecular changes, as in most malignancies. There are conflicting data about the status of HER-2/neu oncogene in urothelial carcinomas. The aim of this study was to determine the status of HER-2/neu oncogene in high-grade invasive urothelial carcinoma of urinary bladder both in protein and DNA level. We evaluated HER-2/neu protein overexpression by immunohistochemistry (IHC) and gene amplification by fluorescent in situ hybridization (FISH) and real-time quantitative PCR in paraffin-embedded samples of high-grade invasive urothelial carcinoma obtained from 36 patients. Polysomy 17 was also assessed by FISH. Immunohistochemically, HER-2/neu protein overexpression was observed in 22 (61.1%) tumors (ten tumors with score 3+ and 12 with score 2+). Fourteen of 36 tumors (38.9%) were evaluated as negative (score 0 or 1+). Complete concordance between FISH and the PCR was seen in all of the samples scored as 0 and 1+ by IHC. HER-2/neu gene amplification was observed in three of 27 (11.1%) tumors by FISH (nine samples were non-informative) and in eight of 36 (22.2%) tumors by the PCR. The complete concordance between HER2-2/neu protein overexpression and gene amplification was seen only in three of 27 tumors. Polysomy 17 was seen in nine tumors (33.3%). The results indicated that, in contrast to breast cancer, there was no strong association between HER-2/neu overexpression and gene amplification in invasive urothelial carcinomas, and polysomy 17 was higher in tumors showing HER-2/neu overexpression.

H pylori iceA alleles are disease-specific virulence factors.

AIM: To characterize and compare genotype profiles of H pylori strains isolated from patients with chronic gastritis and duodenal ulcer in western part of Turkey. METHODS: A total of 46 patients [30 chronic gastritis (CG) and 16 duodenal ulcer (DU)] who had undergone endoscopy because of dyspeptic complaints were studied. The antral biopsy specimens were evaluated for the presence of H pylori by rapid urease test and culture, and the genotype profiles were determined by real-time PCR. RESULTS: The cagA gene was observed in 43 (93.5%) isolates. The vacA s1m2 genotype was the predominant subtype, found in 63.3% and 68.7% of isolates in patients with CG and DU, respectively. Twenty (66.6%) isolates from patients with CG were iceA2 positive while the iceA1 was predominant in those with DU (68.8%). In terms of the association of the iceA alleles to other genes, both alleles were significantly associated with the cagA vacA s1m2 genotype. CONCLUSION: The prevalent circulating genotypes in CG and DU were cagA vacA s1m2 iceA2 and cagA vacA s1m2 iceA1 genotype, respectively. It was found that cagA vacA s1m2 genotype seems to be common virulence factors in both CG and DU while iceA alleles show specificity for gastroduodenal pathologies in this study.

Sex chromosome aneuploidy rates in the somatic cells of infertile men.

OBJECTIVE: A large number of studies have shown that the prevalence of somatic chromosome abnormalities detectable with karyotyping is higher in infertile men. However, a normal somatic karyotype does not exclude the chance of having low level mosaicism. STUDY DESIGN: Eleven men with severe oligozoospermia and 10 healthy, fertile men were included in this study. All the patients had severe oligozoospermia with sperm counts < or =3,000,000/ mL. All participants had normal physical findings and testicular volume. The probe for dual-color fluorescence in situ hybridization consisted of an alpha satellite sequence in the centromeric region of chromosome X (DXZ1) and satellite III DNA at the Yq12 region of chromosome Y (DYZ1). RESULTS: The sex chromosome aneuploidy rate was significantly higher in subjects than in controls (p<0.001). The median incidence of sex chromosome aneuploidy in the oligozoospermic group was 4.5% (range, 0.8-7.3%), while in the control group it was 0.7% (range, 0.2-1.2%)., CONCLUSION: The incidence of aneuploidy in somatic cells is significantly greater in oligozoospermic men than in normal controls. That may suggest that chromosome instability is a result of altered genetic control during mitotic cell division. Our results demonstrate that men with oligozoospermia have an elevated risk for sex chromosome abnormalities in their somatic cells.

Effect of sulfite exposure on zinc, iron, and copper levels in rat liver and kidney tissues.

Sulfite is a potentially toxic molecule that might enter the body via ingestion, inhalation, or injection. For cellular detoxification, mammalians rely on sulfite oxidase to convert sulfite to sulfate. The purpose of this research was to determine the effect of sulfite on zinc, iron, and copper levels in rat liver and kidney tissues. Forty normal and sulfite oxidase-deficient male albino rats were divided into four groups that included untreated controls (group C), a sulfite-supplemented group that received 70 mg sodium metabisulfite per kilogram per day (group S), a sulfite oxidase-deficient group (group D), and a sulfite oxidase-deficient group that was also given 70 mg sodium metabisulfite per kilogram per day (group DS). The iron and zinc levels in the liver and kidney in groups S and DS were not affected by sulfite treatment compared to their respective controls (groups C and D). Sulfite exposure led to an increase of kidney copper content in the S group when compared to untreated controls. The kidney copper levels were significantly increased in the unexposed deficient rats, but it was not different than that of the deficient rats that were given oral sulfite treatment. These results suggest that kidney copper levels might be affected by exogenous or endogenous sulfite.

Beta-thalassemia mutations in Denizli province of Turkey.

Beta-thalassemia is one of the most common genetic disorders in Turkey as well as in several other Mediterranean countries presenting microcytosis and hemolytic anemia. The city of Denizli is located in the inner part of the Aegean geographical region of Turkey. The beta-thalassemia incidence in Denizli province is in between 2.6-3.7% reported by different researchers. According to our results; the IVS-1/nt-110 (G>A) is the most frequent mutation type in our province the same as other geographical regions of Turkey. Here we report also two HbD-Los Angeles/beta-thalassemia combinations, which are HbD-Los Angeles/codon 39 (C>T) and HbD-Los Angeles/IVS-1/nt-1 (G>A), respectively. In conclusion, our preliminary results show the heterogeneity of the beta-thalassemia mutations in the province of Denizli.

Progressive autosomal dominant optic atrophy and sensorineural hearing loss in a Turkish family.

PURPOSE: To describe the clinical features, mode of inheritance, and linkage analysis of ten affected members of a three-generation family with progressive optic atrophy and progressive hearing loss. MATERIALS AND METHODS: The proband, a 10-year-old boy, presented with progressive visual failure. Ten other members in his family, including his mother, half-sister, aunt, two uncles, grandfather, and some of the cousins, also had progressive visual loss and hearing loss. Six affected and four unaffected cases were examined in detail. Blood samples were drawn from 16 members for DNA extraction. Two loci previously described for optic atrophy were tested for linkage in the present family. RESULTS: The mode of inheritance was clearly autosomal dominant. Six members of the family were found to have progressive optic atrophy and hearing loss, both starting in the first decade of life. Total or red-green color blindness was detected in some patients. None of the members of this family showed evidence of other systemic disorders; however, four had blepharochalasis. No other cause could be found for the hearing or the visual loss. Linkage analysis excluded OPA1 and OPA2. CONCLUSION: The present Turkish family belongs to the group of individuals with autosomal dominantly inherited optic atrophies with hearing loss. Linkage analysis excluded OPA1 and OPA2, indicating that a novel gene defect underlies the disease in this family. Further genome-wide linkage analysis and identification of the disease-associated gene will help define the pathophysiology of this syndrome.

[Family history, clinical features, and molecular characterization of a patient with autosomal recessive non-syndromic hearing loss]. / Otozomal resesif isitme kaybi olan bir olguda aile öyküsü, klinik ve moleküler incelemeler.

Autosomal recessive non-syndromic hearing loss is the most common form of inherited childhood deafness. Identification of the responsible gene in this type of hearing loss presents difficulties because of marked genetic heterogenicity and limited clinical presentation. A two-year-old girl was referred to our clinic because of congenital hearing loss. Family history showed that her brother and six relatives of her parents were also affected by unilateral or bilateral hearing loss. There was no consanguinity between the parents, though they were from close villages. Audiometric studies revealed severe bilateral sensorineural hearing loss. Molecular analysis of the index patient documented that autosomal recessive non-syndromic hearing loss resulted from the homozygous 35delG mutation in the connexin 26 gene.

In vivo fluorescence imaging is well-suited for the monitoring of adenovirus directed transgene expression in living organisms.

PURPOSE: We tested a new light detection cooled charge-coupled device (CCD) for in vivo assessment of noninvasive, whole-body fluorescence optical imaging of adenovirus directed enhanced green fluorescent protein (AdEGFP) expression. PROCEDURES: AdEGFP was injected i.v. into BALB/c mice via tail vein. Whole-body fluorescence optical imaging of AdEGFP expression was performed using a Kodak 2000MM Image Station before and after vector administration. RESULTS: EGFP expression was exclusively detected around the abdominal cavity, and the fluorescent signal peaked at day 4 and then remained detectable for at least 30 days. Ex vivo fluorescence imaging confirmed that EGFP expression was restricted to the liver, and transgene expression was homogeneously diffused into all four lobes. CONCLUSIONS: These findings demonstrate that in vivo fluorescence imaging provides functional data indicating the approximate location, magnitude, and duration of AdEGFP expression.

HLA-B51 gene and its expression in association with Behçet's Disease in Denizli Province of Turkey.

Behçet's Disease (BD) is a multisystemic inflammatory disorder as a triad of symptoms including recurrent oral and genital aphthous ulceration, and uveitis with unknown pathogenesis. Many researchers have tried to investigate the association of HLA-B51 gene with the BD. We aimed to investigate the association of the HLA-B51 gene and its expression, also polymorphic structure by PCR, RT-PCR and sequence specific oligonucleotide primers and probes in BD patients (n: 35) and control group (n: 50). According to our results, we did not observe any association in between HLA-B51 gene, its polymorphism, expression and BD patients.

The role of RELN in lissencephaly and neuropsychiatric disease.

Reelin is an extracellular matrix-associated protein important in the regulation of neuronal migration during cerebral cortical development. Point mutations in the RELN gene have been shown to cause an autosomal recessive human brain malformation termed lissencephaly with cerebellar hypoplasia (LCH). Recent work has raised the possibility that reelin may also play a pathogenic role in other neuropsychiatric disorders. We sought, therefore, to define more precisely the phenotype of RELN gene disruption. To do this, we performed a clinical, radiological, and molecular study of a family in whom multiple individuals carry a chromosomal inversion that disrupts the RELN locus. A 6-year-old girl homozygous for the pericentric inversion 46,XX,inv7(p11.2q22) demonstrated the same clinical features that have been previously described in association with RELN point mutations. The girl's brain magnetic resonance imaging (MRI) findings, including pachygyria and severe cerebellar hypoplasia, were identical to those seen with RELN point mutations. Fluorescence in situ hybridization confirmed that one of the breakpoints of this inversion mapped to within the RELN gene, and Western blotting revealed an absence of detectable serum reelin protein. Several relatives who were heterozygous for this inversion were neurologically normal and had no signs of psychotic illness. Our findings demonstrate the distinctive phenotype of LCH, which is easily distinguishable from other forms of lissencephaly. Although RELN appears to be critical for normal cerebral and cerebellar development, its role, if any, in the pathogenesis of psychiatric disorders remains unclear.

Detection of Y chromosomal material in patients with a 45,X karyotype by PCR method.

A 45,X karyotype is one of the common chromosomal abnormalities characterized by short stature, lack of development of secondary sexual characteristics, webbed neck and cubitus valgus. This phenotype was described by Turner in 1938 and was called Turner syndrome (TS). About 40-60% of the patients with TS phenotype have a 45,X karyotype, the rest either have a structurally abnormal X or Y chromosome or mosaicism with a second cell line. Determination of Y chromosome derivatives in patients with a 45,X karyotype is important for the management of these patients due to increased risk of gonadoblastoma. Low level mosaicism of Y chromosome may be missed by cytogenetic methods. The aim of our study is to analyze cryptic Y chromosome derivatives using Y specific sequences in 40 Turkish patients with a pure 45,X karyotype. Fourteen different Y specific sequences along the Y chromosome were selected for the detection of cryptic Y chromosome material by PCR analysis. The present study demonstrated that 2 patients with a 45,X karyotype (5%) have Y specific sequences except sex related region Y (SRY). One of them had displayed enhanced virilisation whereas other showed no virilisation. In conclusion, it has been found by PCR analysis that 5% of patients with a 45,X karyotype have Y chromosome sequences in the absence of any marker chromosome by cytogenetic analysis. The data also suggest that the patients with a 45,X karyotype should be analyzed for the presence of Y chromosome derivatives by sensitive methods, such as PCR, in order to calculate the future risk of developing gonadoblastoma.

Expressions of N-methyl-D-aspartate receptors NR2A and NR2B subunit proteins in normal and sulfite-oxidase deficient rat's hippocampus: effect of exogenous sulfite ingestion.

Sulfites whether ingested or produced through the sulfur-containing amino acids metabolism of the animal are very active molecules and can cause cellular toxicity. Sulfite oxidase (SOX), a heme- and molybdenum containing mitochondrial enzyme, prevents mammalian cells from adverse effects of sulfite toxicity by metabolizing sulfite to sulfate. The present study was aimed to investigate effect of sulfite on the N-methyl-D-aspartate (NMDA) receptor (NMDAR) NR2A and NR2B subunits in hippocampus of normal and SOX-deficient rats. Rats were divided into four groups; (1) control group, which was given rat chow and tap water ad libitum (C), (2) sulfite group, treated with sulfite (25 mg/kg) in drinking water and commercial rat chow ad libitum (S), (3) SOX-deficient group, maintained on high-W/Mo-deficient regimen to produce SOX deficiency (D), and (4) SOX-deficient + sulfite group (DS), prepared as those in the third group and were afterwards given sulfite (25 mg/kg) additionally. Whole treatment schedule were continued for 6 weeks. Sulfite treatment caused a decrease of NR2A and NR2B subunits of the NMDAR in hippocampus of rats in S and DS groups. Interestingly, similar decrement was observed in D group, probably due to increased endogenous sulfite production. In summary, the results indicated that feeding sulfite to the rats may cause down-regulation of NMDARs by degrading NR2A and NR2B subunits of it, which may be considered as a neuro-compensatory mechanism.

Accurate diagnosis of a homozygous G1138A mutation in the fibroblast growth factor receptor 3 gene responsible for achondroplasia.

Achondroplasia is the most common genetic form of dwarfism inherited as an autosomal dominant disorder. Individuals affected with achondroplasia have impaired ability to form bone from cartilage (endochondral bone formation). Homozygous achondroplasia is a neonatal lethal condition. The vast majority of patients with achondroplasia have a G-to-A transition at position 1138 of the fibroblast growth factor receptor 3 (FGFR3) cDNA sequence, resulting in the Gly-to-Arg substitution at position 380 of the FGFR3 protein. This mutation has been diagnosed by SfcI digestion of amplified genomic DNA. However, it has also been demonstrated that the SfcI digestion protocol does not consistently distinguish between DNA samples heterozygous and homozygous for the G1138A substitution. This study was designed to improve the molecular diagnosis based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques for the FGFR3 G1138A mutation. The newly designed forward primer contains one mismatch (G at position 1136) from the FGFR3 cDNA sequence (A at position 1136), thereby creating a PstI site (CTGCAG at positions 1134 to 1139) in the amplified DNA from alleles containing the G1138A mutation. The PCR-RFLP technique based on the PstI digestion of amplified genomic DNA with a novel forward primer shows 100% accuracy in diagnosis of the G1138A mutation in heterozygous and homozygous individuals.

Is Helicobacter pylori a pathogenic agent of the cervix uteri?

BACKGROUND: Helicobacter pylori is a gram-negative, microaerophilic rod-shaped bacterium that lives beneath the gastric mucosal layers, on the surface of epithelial cells. Gastric infection with this organism causes inflammation of the gastric mucosa, which can lead to gastritis, duodenal or gastric ulcers and even in rare cases to gastric carcinoma or MALT lymphoma. Approximately 50% of the population of the entire world is believed to be infected with H. pylori, but the exact route of transmission is still uncertain. It has been speculated that the cervix, with its endocervical columnar epithelium and acidic mucous layer, might provide a suitable environment for H. pylori. H. pylori might be a pathogenic agent for cervical infection. In order to address this issue we studied H. pylori in the endocervical tissue. METHODS: To investigate our hypothesis, we examined cervical tissue using PCR, culture, and Gram-stain. Thirty-three cervices from women who underwent total hysterectomy for noninvasive non-cervical benign uterine diseases were analyzed in this study. Twenty-one patients had cervicitis and 12 patients were included as controls. RESULTS: Of the 29 patients studied, none showed evidence of H. pylori infection. H. pylori was not detected by PCR, histology, or culture. CONCLUSIONS: We could not detect H. pylori in the cervix of patients with cervicitis. H. pylori-infected patients' cervices remain to be investigated, and a larger study is needed to draw firm conclusions.

No association of the CAG repeat length in exon 1 of the androgen receptor gene with idiopathic infertility in Turkish men: implications and literature review.

While the correlation between the CAG repeat length of the androgen receptor (AR) gene and idiopathic male infertility is still unclear, ethnic background of the population studied may play an important role in this association. The objective of this study was to determine whether changes in the CAG repeat length are associated with spermatogenic defects in Turkish infertile men. Reproductive hormone concentrations and the CAG repeat length in exon 1 of the AR gene in 47 idiopathic infertile men and 32 fertile controls were analyzed. The mean serum luteinising hormone (LH) and follicle stimulating hormone (FSH) levels were significantly higher in the infertile group than those of the control group (p < 0.0001 for both comparisons), whereas the mean serum testosterone level in the infertile group did not differ significantly from that in the control group (p = 0.16). The mean CAG repeat length of the AR gene in the infertile group did not differ significantly from that in the control group (22.28 +/- 0.37 vs 22.41 +/- 0.54, respectively; p = 0.84). In addition, the frequency of having a CAG repeat number (> or = 24) was also comparable between the infertile patients and fertile controls (31.9% vs 40.6%, respectively; p = 0.21). In conclusion, reproductive hormones with elevated LH and FSH, and normal or low testosterone levels were suggestive of partial impairment of testicular function. However, no statistically significant relationship between the length of the CAG repeat and idiopathic impaired sperm production was observed in the Turkish population studied. These results support the findings of previously published European studies, but are contrary to the findings from Caucasian and North American population studies. Thus, ethnicity and genetic backgrounds seem to be important in this association, and studies from a variety of different ethnic and genetic backgrounds using comparable patient subgroups are valuable to further evaluate this association.

Cytogenetic studies in patients with reproductive failure.

BACKGROUND: Cytogenetic studies in patients with reproductive failure AIM: To investigate the contribution of chromosomal abnormalities in sub fertility and in couples with repeated abortions. METHODS: Hundred and 13 couples who had at least two or more spontaneous abortions and 65 women and 63 men with infertility were analyzed cytogenetically. RESULTS: Major chromosomal rearrangements were found in 8% and minor variants in 6% in the study population. Major chromosomal aberrations were judged to explain 4.9% of recurrent abortions and 13% of infertility. Chromosomal abnormalities in infertile men occurred in 5% and in infertile women in 21.5%. The chromosomal abnormalities were structural (57%), numerical (18%) or mosaics (25%). CONCLUSIONS: Chromosomal aberrations in recurrent abortions are mostly structural ones and those in female infertility mosaicism of sex chromosomes. Turner's syndrome, Turner variants and XY females are detected as a cause of female infertility. The structural and numerical aberrations of either sex or autosomal chromosomes were found in infertile men.

Incidence and molecular analysis of glucose-6-phosphate dehydrogenase deficiency in the province of Denizli, Turkey.

BACKGROUND: G6PD deficiency is a widespread abnormality of glucose-6-phosphate dehydrogenase, a red cell enzyme, which gives rise to hemolysis under oxidative stress. In Turkey, G6PD deficiency has a variable frequency in different regions. The prevalence and genotypes of G6PD deficiency are not known in Denizli province of the Aegean region of Turkey. Accordingly, this study was designed to investigate the prevalence of enzyme deficiency and the distribution of the Mediterranean mutation of G6PD in this region. MATERIAL/METHODS: A total of 1950 students (918 females, 1032 males, ages between 14 and 17) were screened by the Fluorescent Spot Test, and the G6PD deficiency was confirmed by quantitative spectrophotometric assay. The G6PD deficient subjects were further analyzed by the PCR/RFLP technique to identify the presence of the 563 T Mediterranean mutation. RESULTS: 24 of the subjects were found to be deficient in this enzyme, a frequency of 1.23%. Of 24 deficient subjects, 19 (79%) had the 563 T Mediterranean mutation. CONCLUSIONS: The frequency of G6PD enzyme deficiency appears to be low compared with those found in the malaria-endemic Mediterranean region of Turkey. The molecular pathology of G6PD deficiency is related to the G6PD-563 T mutation in the Denizli region.

Familial influence on parkinsonism in a rural area of Turkey (Kizilcaboluk-Denizli): a community-based case-control study.

This population-based study on parkinsonism in a genetically isolated community from a rural area of Turkey aimed to provide a selective evaluation of environmental and heritable risk factors. An increased prevalence of parkinsonism (4.1%) was detected in the village of Kizilcaboluk for people 65 years of age and older. This study included 36 patients with parkinsonism living in Kizilcaboluk and three times that number of age- and sex-matched people serving as controls. A questionnaire including demographic data, family history, education, occupation, data on exposures to pesticides, smoking, alcohol intake, and head trauma was administered. We found a significant association of parkinsonism cases with a positive family history in first-degree relatives (odds ratio [OR], 7.48; 95% confidence interval [CI], 2.52-22.17; P < 0.0001) and with pesticide exposure (OR, 2.96; 95% CI, 1.31-6.69; P = 0.015) compared to the control subjects. The value of genetically isolated populations for the identification of genetic risk factors for common and complex disorders has gained much attention recently because the genetic make-up of these populations is likely to be less complex than that of the general population and our findings should prompt investigations to the nature of a familial aggregation of parkinsonism in this population.