human immunodeficiency virus ( hiv)-1 infection has spread to all population groups in india and has reached epidemic proportions . the rate of progression of hiv-1 disease exhibits a remarkable variation among different individuals .
many host genetic factors are now known to affect the disease progression rates , especially polymorphisms in genes encoding chemokine receptors .
although , no studies on chemokine receptor polymorphisms have been reported in the endogamous population of state of maharashtra state so far , only one study has been carried out in healthy individuals of tribes and muslim ethnic groups of andhra pradesh , south india .
certain members of the chemokine family of receptors serve as critical portals for the entry of hiv-1 into target cells . a mutant allele ( cc - chemokine receptor-5 [ ccr5]-32 ) of the -chemokine receptor gene
ccr5 carrying a 32 base - pair deletion prevents cell invasion by the primary transmitting strain of hiv-1 .
individuals who are homozygous for the ccr5-32/32 allele are highly resistant to hiv-1 infection ; the heterozygote state does not protect against hiv-1 infection , although , heterozygotes have been found to have significantly lower viral loads .
early reports indicated that the ccr5-32 allele maybe absent in indigenous non - european populations .
the ccr5_32 allele appears to have originated quite recently ( approximately 7,000 years ago ) in northeastern europe .
although its frequency has now reached a relatively high level in europeans , e.g. , 16.3% in finns and 15.8% in moravians , it is not present among african populations , and is only so at low levels in the asian .
hence , by application it is possible to evaluate the influence of the european population on the genetic constitution of others . in india population
one study has been carried out in healthy individuals of the tribes and muslim ethnic groups of andhra pradesh , south india .
majumder and dey , reported absence of ccr5-32 in various ethnic populations of india , both tribal and non - tribal , except for some populations of the northern and western regions where this allele may have been introduced by caucasian gene flow .
although a few studies on chemokine , chemokine receptor , and dcsign exon 4 repeat number polymorphisms have been reported in north indian ( aryan descent ) hiv patients and healthy controls , there is a dearth of reports on the hiv patients with and without tuberculosis ( tb ) of south indian ( dravidian descent ) origin .
ccr5-32 exhibit variable frequencies in distinct populations and possibly , their phenotypes depend on the ethnicity analyzed .
the brazilian population presents a complex genetic background , characterized by a high degree of miscegenation . in major brazilian cities ,
such diversity is some time attributed to the positioning of the indian peninsula at the tri - junction of the three continents , viz .
the contemporary indian population is stratified as tribal and non - tribal , i.e. , caste population .
the origin of the caste in india is an enigma , though many are known to have a tribal origin .
the maharashtra state of india forms a huge irregular triangle with its base on the west cost of india , overlooking the arabian sea .
historically , the state is comprised of three sub - regions , western maharashtra , the vidarbha , and the marathwada .
vidarbha lies on the eastern side and thus mainly contributes to the region broadly referred to as central india .
apart from the tribal population , many other ethnic communities mainly hindus , muslim , buddhist and sikhs , inhabit the region .
the vidarbha has a hoary past and has been under the domination of many hindus , muslims , and tribal - gond kingdoms .
it is assumed that the relationship between these various populations may define the present genetic landscape of india . taking this assumption and geographical and ethnic diversity into account in the present study , we investigated the distribution of ccr5-32 alleles in tribes from the vidarbha region ( maharashtra ) central india .
besides inhabiting the adjoining state , a substantial number of these people inhabit in few district of vidarbha .
bhils are listed as adivasi residents of the states of gujarat , madhya pradesh , chhattisgarh , maharashtra , and rajasthan in western and central india as well as in tripura in far - eastern india on the border with bangladesh .
bhils are divided into a number of endogamous territorial divisions , which in turn have a number of clans and lineages .
most bhils now speak the language of the region they reside in , such as marathi and gujarati .
the korkus are a typical tribal population from amravati district and found only in the satpuda mountain ranges spanning maharashtra and madhya pradesh .
they are mainly concentrated in melghat a scheduled area of korku comprising 89% of the tribal population .
the phasse are a sub tribe of the paradhi caste , which includes sub - castes like gav paradhi , berad - paradhi , gay - paradhi , chita paradhi .
 there are only three surnames among them , chauhan , pawar , and solanke .
we sampled 15 samples from this group from akola district . a low cultivating caste of berar , who numbered 52,000 persons in 1911 , and belongs to the yeotmal , akola , and buldana districts .
the andhs appear to be a non - aryan tribe of the andhra or tamil country , from which they derive their name .
there were 8228 andh in andhra pradesh in 1991 . according to singh et al .
, in their 2004 book people of india there are over 74,000 andhs in maharashtra .
this tribe falls under the primitive tribes category and spread much over the central india .
gond generally speaks  gondi  dialect , which belongs to the dravidian linguistic family , after indo - european , in india .
brahmin is a class of priests and preachers of  dharma and considered as the torch bearer of hinduism .
majority of brahmin in maharashtra speak marathi , one of the major languages of indo - aryan linguistic group .
we have collected 108 blood samples on whatman fta mini cards ( ge health - care , uk , ltd ) from 6 tribe 's populations and a caste population from the district of vidarbha region .
every card was labeled with appropriate code as per tribes / caste and district with informed consent obtained from each volunteer .
approximately , ( 200 l [ 2 - 5 drop ] ) of blood by veni - puncture was directly spotted on the fta mini card within a printed circle area and dried at room temperature .
briefly , 100 ng of genomic dna was denatured at 94c for 10 min , following , which it was subjected to 30 cycles of denaturation , annealing , and extension .
the reaction mixture of 50 l contained , 50 mmol kcl , 10 mmol tris - hcl , ph 8.3 , 800 mol dntps , 100 g / ml gelatin , 10 pmoles of each of the ccr5-specific primer forward : ccr5  f : ( 5-cctggctgtcgtccatgctg-3 ) and reverse : ccr5-r : ( 5-ctgatctagagccatgtgcac aactct-3 ) . , and 1.5 units of taq polymerase enzyme ( xcelris genomics , ahmedabad , india ) .
the genotypes were visualized by running digested product on 2% agarose gel at 100 v for about 2 h and the results were recorded in gel documentation system .
the ecori restriction enzymes digest the amplified polymerization chain reaction ( pcr ) product of 735 base pairs ( bps ) .
the amplified product was digested with 10 u of ecori at 37c for 2 h. after digestion , the products were analyzed on a 2% agarose gel and bands were visualized on a ultraviolet ( uv)-transilluminator .
pcr amplified a 735 bp region of genomic dna that spanned a 32-bp deletion differentiating the ccr5-_32 allele from its wild - type counterparts at the ccr5 locus .
after restriction digestion with ecori , with wild gene yielded band at 332 bp and for mutated gene , the bands were at 332 and 403 figure 1 .
cc - chemokine receptor-5 genotyping among the tribes lane 1 , 2 , 3 , 5 , 6 and 7 represent the pcr product from samples with homozygous wild type genotypes ( fragments of 332 bp wt / wt ) .
lane 4 represents the -32 genotype ( with the presence of both fragment of 332 and 403 wt/32 ) statistical analysis of allele frequencies was performed using chi - square statistics .
genotype distribution for polymorphism was first compared to predictable values from hardy  weinberg equilibrium . in all cases ,
besides inhabiting the adjoining state , a substantial number of these people inhabit in few district of vidarbha .
bhils are listed as adivasi residents of the states of gujarat , madhya pradesh , chhattisgarh , maharashtra , and rajasthan in western and central india as well as in tripura in far - eastern india on the border with bangladesh .
bhils are divided into a number of endogamous territorial divisions , which in turn have a number of clans and lineages .
most bhils now speak the language of the region they reside in , such as marathi and gujarati .
the korkus are a typical tribal population from amravati district and found only in the satpuda mountain ranges spanning maharashtra and madhya pradesh .
they are mainly concentrated in melghat a scheduled area of korku comprising 89% of the tribal population .
the phasse are a sub tribe of the paradhi caste , which includes sub - castes like gav paradhi , berad - paradhi , gay - paradhi , chita paradhi .
 there are only three surnames among them , chauhan , pawar , and solanke .
we sampled 15 samples from this group from akola district . a low cultivating caste of berar , who numbered 52,000 persons in 1911 , and belongs to the yeotmal , akola , and buldana districts .
the andhs appear to be a non - aryan tribe of the andhra or tamil country , from which they derive their name .
there were 8228 andh in andhra pradesh in 1991 . according to singh et al .
, in their 2004 book people of india there are over 74,000 andhs in maharashtra .
this tribe falls under the primitive tribes category and spread much over the central india .
gond generally speaks  gondi  dialect , which belongs to the dravidian linguistic family , after indo - european , in india .
brahmin is a class of priests and preachers of  dharma and considered as the torch bearer of hinduism .
majority of brahmin in maharashtra speak marathi , one of the major languages of indo - aryan linguistic group .
we have collected 108 blood samples on whatman fta mini cards ( ge health - care , uk , ltd ) from 6 tribe 's populations and a caste population from the district of vidarbha region .
every card was labeled with appropriate code as per tribes / caste and district with informed consent obtained from each volunteer .
approximately , ( 200 l [ 2 - 5 drop ] ) of blood by veni - puncture was directly spotted on the fta mini card within a printed circle area and dried at room temperature .
briefly , 100 ng of genomic dna was denatured at 94c for 10 min , following , which it was subjected to 30 cycles of denaturation , annealing , and extension .
the reaction mixture of 50 l contained , 50 mmol kcl , 10 mmol tris - hcl , ph 8.3 , 800 mol dntps , 100 g / ml gelatin , 10 pmoles of each of the ccr5-specific primer forward : ccr5  f : ( 5-cctggctgtcgtccatgctg-3 ) and reverse : ccr5-r : ( 5-ctgatctagagccatgtgcac aactct-3 ) . , and 1.5 units of taq polymerase enzyme ( xcelris genomics , ahmedabad , india ) .
the genotypes were visualized by running digested product on 2% agarose gel at 100 v for about 2 h and the results were recorded in gel documentation system .
the ecori restriction enzymes digest the amplified polymerization chain reaction ( pcr ) product of 735 base pairs ( bps ) .
the amplified product was digested with 10 u of ecori at 37c for 2 h. after digestion , the products were analyzed on a 2% agarose gel and bands were visualized on a ultraviolet ( uv)-transilluminator .
pcr amplified a 735 bp region of genomic dna that spanned a 32-bp deletion differentiating the ccr5-_32 allele from its wild - type counterparts at the ccr5 locus .
after restriction digestion with ecori , with wild gene yielded band at 332 bp and for mutated gene , the bands were at 332 and 403 figure 1 .
cc - chemokine receptor-5 genotyping among the tribes lane 1 , 2 , 3 , 5 , 6 and 7 represent the pcr product from samples with homozygous wild type genotypes ( fragments of 332 bp wt / wt ) .
lane 4 represents the -32 genotype ( with the presence of both fragment of 332 and 403 wt/32 ) statistical analysis of allele frequencies was performed using chi - square statistics .
genotype distribution for polymorphism was first compared to predictable values from hardy  weinberg equilibrium . in all cases ,
besides inhabiting the adjoining state , a substantial number of these people inhabit in few district of vidarbha .
bhils are listed as adivasi residents of the states of gujarat , madhya pradesh , chhattisgarh , maharashtra , and rajasthan in western and central india as well as in tripura in far - eastern india on the border with bangladesh .
bhils are divided into a number of endogamous territorial divisions , which in turn have a number of clans and lineages .
most bhils now speak the language of the region they reside in , such as marathi and gujarati .
the korkus are a typical tribal population from amravati district and found only in the satpuda mountain ranges spanning maharashtra and madhya pradesh .
they are mainly concentrated in melghat a scheduled area of korku comprising 89% of the tribal population .
the phasse are a sub tribe of the paradhi caste , which includes sub - castes like gav paradhi , berad - paradhi , gay - paradhi , chita paradhi .
 there are only three surnames among them , chauhan , pawar , and solanke .
we sampled 15 samples from this group from akola district . a low cultivating caste of berar , who numbered 52,000 persons in 1911 , and belongs to the yeotmal , akola , and buldana districts .
the andhs appear to be a non - aryan tribe of the andhra or tamil country , from which they derive their name .
there were 8228 andh in andhra pradesh in 1991 . according to singh et al .
, in their 2004 book people of india there are over 74,000 andhs in maharashtra .
this tribe falls under the primitive tribes category and spread much over the central india .
gond generally speaks  gondi  dialect , which belongs to the dravidian linguistic family , after indo - european , in india .
brahmin is a class of priests and preachers of  dharma and considered as the torch bearer of hinduism .
majority of brahmin in maharashtra speak marathi , one of the major languages of indo - aryan linguistic group .
we have collected 108 blood samples on whatman fta mini cards ( ge health - care , uk , ltd ) from 6 tribe 's populations and a caste population from the district of vidarbha region .
every card was labeled with appropriate code as per tribes / caste and district with informed consent obtained from each volunteer .
approximately , ( 200 l [ 2 - 5 drop ] ) of blood by veni - puncture was directly spotted on the fta mini card within a printed circle area and dried at room temperature .
polymerase chain reaction was performed following previously prescribed protocol by . briefly , 100 ng of genomic dna was denatured at 94c for 10 min , following , which it was subjected to 30 cycles of denaturation , annealing , and extension .
the reaction mixture of 50 l contained , 50 mmol kcl , 10 mmol tris - hcl , ph 8.3 , 800 mol dntps , 100 g / ml gelatin , 10 pmoles of each of the ccr5-specific primer forward : ccr5  f : ( 5-cctggctgtcgtccatgctg-3 ) and reverse : ccr5-r : ( 5-ctgatctagagccatgtgcac aactct-3 ) . , and 1.5 units of taq polymerase enzyme ( xcelris genomics , ahmedabad , india ) .
the genotypes were visualized by running digested product on 2% agarose gel at 100 v for about 2 h and the results were recorded in gel documentation system .
the ecori restriction enzymes digest the amplified polymerization chain reaction ( pcr ) product of 735 base pairs ( bps ) .
the amplified product was digested with 10 u of ecori at 37c for 2 h. after digestion , the products were analyzed on a 2% agarose gel and bands were visualized on a ultraviolet ( uv)-transilluminator .
pcr amplified a 735 bp region of genomic dna that spanned a 32-bp deletion differentiating the ccr5-_32 allele from its wild - type counterparts at the ccr5 locus .
after restriction digestion with ecori , with wild gene yielded band at 332 bp and for mutated gene , the bands were at 332 and 403 figure 1 .
cc - chemokine receptor-5 genotyping among the tribes lane 1 , 2 , 3 , 5 , 6 and 7 represent the pcr product from samples with homozygous wild type genotypes ( fragments of 332 bp wt / wt ) .
lane 4 represents the -32 genotype ( with the presence of both fragment of 332 and 403 wt/32 )
genotype distribution for polymorphism was first compared to predictable values from hardy  weinberg equilibrium . in all cases ,
our data on distribution of ccr5-32 mutation among the selected tribe and a caste is depleted table 1 .
genotype and phenotype for the heterozygous mutation among the tribes sample suggested that it is either absent or present at low frequency 1.08% ( 1 in 93 tribe 's samples and 1 in 15 samples of a caste ) .
none of the tribes and control caste was found to be homozygous for the ccr5-32 mutation , while the bhil tribe and control caste show the heterozygous for the ccr5-32 mutation in negligible frequency ( 0.034 ) .
the analysis of  suggested that the prevalence of the ccr5-32 is significantly low ( = 0.02 , p > 0.05 ) .
the aggregate frequencies of the entire sample for the wild - type allele ccr5 and the ccr-5-32 variant were found to be 0.991 and 0.009 , respectively . among the tribes kolam , korku , paradhi , andh and
while only the bhil tribe shows heterozygous genotype frequency ( 06.97% ) and allelic frequency ( 0.034 ) for ccr5/32 .
only one bearer of this mutation was found in the blood sample of bhil tribe collected from yavatmal district of vidarbha region .
genotypic distribution and gene frequencies of the ccr5 allele in different population samples of vidarbha region of maharashtra state no significant deviations from the hwe were observed ( p > 0.05 , chi - squared goodness of fit ) .
table 1 shows the frequency of the ccr5-32 allele in the six tribes and one control caste brahmin population .
this study describes the genotype and allele frequencies of the polymorphisms ccr5-32 in selected six tribal and one caste populations from vidarbha region .
most importantly , however , this study is the first to be conducted in vidarbha that investigates the genetic polymorphisms ccr5-32 among different ethnic tribal population settlement in the districts of vidarbha region .
ccr5 , a coreceptor for hiv - i virus , has been shown to be the most important for the hiv transmission .
a 32-nucleotide deletion of ccr5 homozygous ( ccr5-32/32 ) display a high degree of the natural resistance to hiv transmission whereas ccr5-32 heterozygosity ( ccr5+/32 ) demonstrate a slower progression to acquired immunodeficiency syndrome ( aids ) than ccr5 wild type ( ccr5+/+ ) .
however , this genetic mutation is found in caucasian rather than non - caucasian population including india . the ccr5-32 genotype frequency among our study tribes sample was absent or negligible , the average genotype frequency were common homozygous wt / wt ( 98.3% ) , heterozygous wt / mt ( 1.87% ) and rare homozygous mt / mt ( 0% ) , from the control group , revealing ccr5-32 allele frequency of 6.97% .
the frequency of the ccr5-32 allele among our study population seems to be remarkably similar to previously reported frequencies in other asian populations .
the ccr5-32 allele frequency among asians is very low in rajasthan indians ( 0.05% ) , andhra pradesh indians ( 0 - 0.03% ) , north indians ( 1.5% ) , south indians ( 1 - 3% ) , and ethnic population of kashmir ( 3 - 4% ) .
a similar study conducted from the island of crete , greece showed allele frequency of 3.25% , with a 95% confidence interval ( ci ) for conformity with hardy - weinberg equilibrium of 0.74 - 5.7% .
the ccr5-32 polymorphism is found all across europe at different allele frequencies , with a north to south decreasing gradient and lower distribution in the regions of southeast mediterranean .
the frequency of the ccr5-32 allele in the studied tribal population is consistently similar with data reported from other populations with non - european ancestors .
ccr5-32 allelic frequencies were not different when the self - reported racial characteristics of the individuals evaluated were considered .
this allele has not been found among south american native indians , corroborating the hypothesis of a european origin of this allele and its introduction to the continent through migration . within the middle - eastern populations
the frequency of the mutant ccr5-32 allele reached it 's the highest among iranians , 2.4% ; saudi , 2.1% ; and it 's the lowest among kuwaitis , 1% ; and the egyptians , 0.5% ; and is completely absent in individuals from the united arab emirates .
our results suggest that the ccr5-32 allele is detected at very low frequency in studied tribal populations from vidarbha .
the presence of low frequencies of ccr5-32 in an individual of bhil tribe ( 0.034 ,  value 0.017 ) in the present study implies that these communities may have a better resistance to hiv / aids than other studied tribe sample , as non show such mutation .
the marginal presence of the allele seen in the studied tribal population could be due to gene flow from the people of european descent .
however , ccr5-32 is completely absent in the populations from africa , oceania , and the americas .
however , lack of the homozygous ccr5-32 mutation and the low prevalence of heterozygous ccr5-32 mutations suggest that the indians are highly susceptible to hiv / aids , and this correlates with the highest number of hiv / aids infected individuals in india .
 background : genetic relationships among the ethnic groups are not uniform across the geographical region . considering this assumption 
 , we analyzed the frequency of the cc - chemokine receptor-5 ( ccr5)-32 allele of the ccr5 chemokine receptor , which is considered a caucasian marker , in bhil tribal and brahmin caste sample sets from the population.materials and methods:108 blood samples were collected from 6 tribe 's populations and a caste population from the district of vidarbha region.results and discussion : the presence of low frequencies of ccr5-32 in an individual of bhil tribe ( 0.034 , 2 value 0.017 ) in the present study implies that these communities may have a better resistance toward human immunodeficiency virus ( hiv)/acquired immunodeficiency syndrome ( aids ) than the other studied tribe sample , as non - show such mutation.conclusion:the marginal presence of the allele seen in the studied tribal population could be due to gene flow from the people of european descent . 
 however , lack of the homozygous ccr5-32 mutation and the low prevalence of heterozygous ccr5-32 mutations suggest that the indians are highly susceptible to hiv / aids , and this correlates with the highest number of hiv / aids infected individuals in india . 
Introduction
Material and Methods
None
Population
Blood sample collection and DNA extraction
Amplification and restriction digestion of DNA
Genotyping for CCR5 -32 polymorphism
Statistical analysis
Observation and Results
Discussion and Conclusion