schizophrenia is a serious and neurodevelopmental disorder , which affects approximately 1% of the general population often - devastating effects such as psychological , social and financial skills .
schizophrenia can disturb memory , attention , thought and motivation of affected patients ( 1 ) .
twin concordance rates , family and adoption studies , genetic linkage and allelic association analyses revealed a strong genetic element contributing to schizophrenia ( 2 ) .
therefore , due to the high percentage of heredity involvement , over 1000 genes have been tested to assess such an association .
this makes schizophrenia one of the most studied disorders through a candidate gene approach ( 4 , 5 ) .
caveolins ( encoded by cav1 gene ) are multifunctional scaffolding and cholesterol binding proteins organizing other lipids and proteins in surface domains ; also they regulate various cellular functions such as lipid homeostasis , vesicular trafficking and signal transduction .
in fact , caveolin is extensively expressed in the nervous systems ( 7 - 11 ) . in cav1
knock - out mice , neurodegeneration and aging is more advanced than normal mice ( 12 , 13 ) . current analyses of genomic structural variations in patients with schizophrenia showed that caveolin-1 gene ( cav1 ) is disrupted by an insertion mutation , therefore the cav1 is identified as a rare structural variant correlated with schizophrenia ( 14 ) .
given the importance of this region in neurodegenerative diseases , any changes in this area of genome may result in illnesses such as schizophrenia .
cav1 is also known as an interacting partner of g - protein and its loss can cause destruction of neuronal signaling leading to signs of schizophrenia in susceptible persons ( 9 - 11 ) .
the purine rich complex at the 1.5 kb upper region of the human cav1 gene is composed of three tandem strs of ggaa , gaaa and ggaa motifs , which is conserved in different species as shown in table 1 ( 15 , 16 ) . a skew in the homozygous haplotype of this region in patients with multiple sclerosis ( ms ) and late onset alzheimer s disease ( ad ) has been reported versus controls .
twenty homozygous haplotypes have been identified in two neurodegenerative disorders increasing cav1 gene expression ( 17 ) .
in the current study , test and trails were conducted and observed , to obtain a correlation between the genome area and schizophrenia .
in this case - control study , 127 unrelated patients with schizophrenia were included ( diagnosed based on diagnostic and statistical manual of mental disorders , fourth edition , 1994 , dsm - iv ) .
patients with iq below 90 , major depression , bipolar disorder and abuse of amphetamine and cannabis were excluded .
samples were selected from 22 bahman hospital , a psychology special hospital of qazvin university of medical sciences ( qums ) , iran .
the 22 bahman hospitals is a referral psychology center , which has four sections with 100 beds .
patients were selected by a psychologist using consecutive sampling method from april 2012 to april 2013 . furthermore , 127 healthy subjects were selected as controls .
cases and controls were 51% males and 49% females and their mean age was 41.5 years .
an informed consent was obtained from all participants and the study was approved in the ethics committee ( ethic no ; 93.04.03 - 8890).the sample size was calculated according to this formula : f = 15% ( loss to follow - up ) , 1- = 95% , 1- = 80% , p0 = 0.18 , p1 = 0.35 all laboratory techniques were performed in molecular and cellular research center of qums .
the pcr primers were designed by primer three tools for amplifying upstream region of the cav1 gene .
pcr reactions were performed in 25 l volume , including 100 ng genomic dna , 10 pmol of each primer , 12.5 microliter mastermix ( takara ; japan ) and 10 microliters of distilled water .
pcr temperature profiles were initially denaturized at 95c for three minutes , 30 seconds at 95c , 30 seconds at 60c , 30 seconds at 72c , for 30 cycles , followed by five minutes final extension at 72c .
the produced fragments with 388 bp were detected on 10% polyacrylamide gel by electrophoresis and silver staining .
we looked for three tandem strs of ggaa , gaaa , and ggaa motifs in sequenced fragments .
the pcr primers were designed by primer three tools for amplifying upstream region of the cav1 gene .
pcr reactions were performed in 25 l volume , including 100 ng genomic dna , 10 pmol of each primer , 12.5 microliter mastermix ( takara ; japan ) and 10 microliters of distilled water .
pcr temperature profiles were initially denaturized at 95c for three minutes , 30 seconds at 95c , 30 seconds at 60c , 30 seconds at 72c , for 30 cycles , followed by five minutes final extension at 72c .
the produced fragments with 388 bp were detected on 10% polyacrylamide gel by electrophoresis and silver staining .
we looked for three tandem strs of ggaa , gaaa , and ggaa motifs in sequenced fragments .
all pcr products were sequenced to check this region . an example image of the sequences
we detected nine homozygotes in patients with schizophrenia and 15 homozygotes in the control subjects .
nine different types of homozygote haplotypes with different repeat numbers were detected in cases and controls .
some of homozygote haplotypes were detected in both patients and controls , but a number of haplotype lengths were found in cases and not observed in the controls and some of haplotype lengths were identified in controls and not observed in the cases .
these haplotypes contained 4 - 13 - 7 ( 110 bp ) , 5 - 10 - 8 ( 114 bp ) , 5 - 12 - 9 ( 118 bp ) and 6 - 13 - 8 ( 110bp ) ( table 3 ) , while haplotypes 4 - 12 - 7 ( 106 bp ) , 7 - 11 - 9 ( 118 bp ) , 11 - 12 - 6 ( 126 bp ) , 7 - 12 - 8 ( 124 bp ) and 11,10,8 ( 130 bp ) only existed in controls ( haplotypes 6 - 9 , table 3 ) .
only one haplotype was seen in cases only ( haplotype n. 4 , table 3 ) .
this figure shows tandem strs of ggaa , gaaa , ggaa motifs and haplotype length [ e.g. 126-bp ( 11 - 12 - 6 haplotype ) ] .
there are a number of reports about implicating purine complex of upstream cav1 human gene involvement in pathophysiology of neurodegenerative diseases such as multiple sclerosis ( ms ) and alzheimer 's disease ( ad ) ( 8 , 18 ) . according to existing information ,
this region is conserved across several species , and consists of ggaa , gaaa and ggaa motifs , transcription consensus sites for the ets and irf ( interferon regulatory factor ) family members .
the interaction between ets and irf family members has been shown in different studies ( 7 , 8) .
furthermore , inflammation plays a role in neurodegenerative diseases and several inflammatory transcription factors like stat4 and interferon regulatory factor ( irf ) .
in which , these factors bind to the cav1 upstream purine complex and regulate target genes ( 12 , 19 , 20 ) . some literatures categorized schizophrenia as a neurodegenerative disease ( 1 , 14 ) . to examine the hypothesis that purine complex of upstream cav1
may be related to pathogenesis of schizophrenia , we investigated this region in a group of patients with schizophrenia and compared the results with well - matched controls . in this research , homozygote haplotypes of ggaa , gaaa and ggaa motifs
chi square test showed that these haplotypes significantly related to object ( e.g. haplotype 4 , table 3 , p = 0.016 , p < 0.05 ) .
statistical analysis showed no significant association between these haplotypes and schizophrenia ( for example ; haplotype 6 , table 3 , p = 0.15 , 7 and 8 p = 0.25 , p > 0.05 ) .
these findings implied a significant correlation between schizophrenia and some haplotypes of this region of cav1 gene .
existence of some haplotypes and lack of another in cav1 upstream can suggest a significant correlation between schizophrenia and some haplotypes . to the best of our knowledge ,
this was the first study to assess the association between purine complex upstream region of human cav1 and schizophrenia disease .
 background : caveolin is a multifunctional and scaffolding membrane protein , which involves cholesterol trafficking to plasma lipid microdomain . 
 it organizes and targets synaptic parts of the neurotransmitter and neurotrophic receptor signaling pathways . 
 caveolins are encoded by cav-1 , 2 and 3 genes . 
 disruption of the cav1 would likely ruin the neuronal signaling , which leads to symptoms of schizophrenia in predisposed individuals.objectives:the upper area of cav-1 gene is highly conserved and can have a regulatory role in neurodegenerative diseases . 
 this study was designed to find out the possible association of polymorphisms of this area and schizophrenia.patients and methods : in a case - control study , 254 blood samples were obtained from 127 patients with schizophrenia and 127 well matched controls referred to 22 bahman hospital of qazvin university of medical sciences ( qums ) in qazvin province , iran , using simple random sampling method . after extracting dna , the upper region of the human cav1- gene was amplified by pcr in all collected samples . 
 the products were visualized by silver staining in 10% polyacrylamide gel and then sequenced.results:we detected nine homozygotes in patients and 15 in control subjects . 
 homozygosity was 7.08% and 11.8% in cases and control , respectively . 
 nine types homozygote haplotype were detected in upper region of the cav1 gene in cases and controls . 
 three haplotypes were common in cases and controls ; four haplotypes were seen in controls only and two in cases.conclusions:our findings implied a significant correlation between some haplotypes of upper region of cav1 gene and schizophrenia . 
 existence of some haplotypes and lack of another in cav1 upstream can suggest a significant correlation between schizophrenia and some haplotypes . 
1. Background
2. Objectives
3. Patients and Methods
3.1. PCR and Sequencing
4. Results
5. Discussion