Haplotipic associations of the two most common HLA-B*27 alleles in the Croatian population

Cilj ovog rada bio je analizirati produžene haplotipove dva najčešća podtipa gena HLA-B*27 (B*2702 i *2705) u hrvatskoj populaciji. Analizirana je skupina od 111 nesrodnih ispitanika pozitivnih za gen HLA-B*27, koji do početka ovog istraživanja nisu imali nikakve simptome ankilozantnog spondilitisa. Ukupan broj praćenih haplotipskih veza bio je 112 jer je jedna osoba bila homozigot za gen HLA-B*27. Podtip gena HLA-B*27 i geni na lokusu HLA-A i -DRB1 određeni su metodom PCR-SSP kod svih ispitanika. Od 7 različitih podtipova gena HLA-B*27 uočenih među našim ispitanicima, najčešći je bio alel B*2705 (61,6%) te alel B*2702 (30,4%), dok su preostali aleli (B*2701, B*2703, B*2704, B*2708 i B*2714) uočeni jedanput, odnosno, dvaput. Najčešći gen na lokusu HLA-A bio je HLA-A*02, kako unutar haplotipskih veza alela B*2702 tako i unutar veza alela B*2705. Nije uočena razlika u zastupljenosti gena na ovom lokusu između haplotipskih veza alela B*2702 i alela B*2705. Analiza haplotipskih veza HLA-B, -DRB1 ukazala je na jaku povezanost alela B*2702 i DRB1*16 koji su se zajedno pojavili s učestalošću od 44,1%, što je statistički značajno u usporedbi s učestalošću s kojom se DRB1*16 pojavio unutar haplotipskih veza alela B*2705 (4,0%; P<0,00001). Unutar skupine od 69 haplotipskih veza alela B*2705 uočena je statistički značajno povećana učestalost HLA-DRB1*01 u usporedbi sa skupinom (N=34) haplotipskih veza alela B*2702 (28,0% naspram 1,5%; P<0,00001).The aim of the present study was to analyze haplotypic associations of two the most common HLA-B*27 subtypes (B*2702 and *2705) in the Croatian population. One hundred and eleven unrelated HLA-B*27 positive individuals were included. None of them had any sign of ankylosing spondylitis. The total number of analyzed haplotypic associations was 112 because one individual was homozygous for HLA-B*27. HLA-B*27 alleles as well as HLA-A and DRB1 specificities were tested by PCR-SSP method. Among seven different HLA-B*27 alleles observed among our individuals, B*2705 was the most frequent (61.6%), followed by B*2702 (30.4%), while the frequency of all other observed alleles (B*2701, B*2703, B*2704, B*2708 i B*2714) was less than 2.0%. HLA-A*02 was the most frequent specificity at HLA-A locus in both groups of haplotypic associations (B*2702 and B*2705) and no difference in distribution of HLA-A genes was observed between two groups. Analysis of HLA-B*2702 haplotypic associations showed the high frequency of DRB1*16 (44.2%) in comparison to B*2705 haplotypic associations (4.0%) with significant P value (P<0.00001). HLA-DRB1*01 demonstrated significantly higher presence among 69 B*2705 haplotypic associations compared to 34 B*2702 haplotypic associations (28.0% vs. 1.5%; P<0.00001)

Rapid Prenatal Diagnosis of Numerical Aberrations of Chromosome 21 and 18 by PCR-STR Method

In this study we reported the results for the first time of applying Polymerase Chain Reaction-Short Tandem Repeats (PCR-STR) method in the field of detection of aneuploidies for chromosomes 21 and 18 in Croatians. The aims of the study were: (I) validation of the diagnostic informativeness of 6 STR loci (D18S51, D18S858, D18S535, D21S1435, D21S1411, and D21S1414) in sample of 205 unrelated healthy individuals; (II) evaluation of diagnostic power of the PCR-STR method for those 6 microsatellites; (III) establishment protocol for use STRs as routine method for rapid prenatal detection of trisomy 21 and 18. DNA samples were amplified by fluorescence-based PCR reaction, subjected to electrophoresis in automated laser fluorescence DNA sequencer (ALFexpress). Results of our study were: (I) all 6 tested loci are informative (68–85% of heterozygous individuals); (II) comparison between PCR-STR method and conventional cytogenetics did not revealed any false positive or false negative results; (III) in prenatal screening of 105 samples of uncultured amniotic fluid 6 (5.7%) samples with chromosomal abnormalities were identified

The distribution of HLA alleles class I and class II among patientes with psoriatic arthritis in Croatia

Cilj ovog rada bio je istražiti raspodjelu alela lokusa HLA-A, -B, -Cw i DRB1 među bolesnicima s psorijatičnim artritisom (PsA) u Hrvatskoj. DNA, izolirana iz uzorka periferne krvi 58 bolesnika (28 muškaraca i 30 žena) i 157 kontrolnih osoba, testirana je metodom lančane reakcije polimerazom i primerima specifičnih sekvenci (PCR-SSP) za polimorfizam navedenih lokusa HLA. Najjaču povezanost s PsA među hrvatskim bolesnicima pokazali su aleli lokusa HLA-B (B*39 i B*57), dok su aleli B*27 i B*13 pokazali povišenu učestalost samo prije korekcije p vrijednosti. Povišena zastupljenost alela Cw*02, te alela DRB1*16 posljedica je neravnoteže udruživanja tih alela s alelima lokusa HLA-B koji su povezani s PsA u Hrvatskoj. Među bolesnicima je smanjena zastupljenost alela B*0702, B*18 i B*38.The aim of the present study was to analyze the distribution of HLA-A, -B, -Cw, and -DRB1 alleles among patients with psoriatic arthritis (PsA) in Croatia. DNA was isolated from peripheral blood of 58 PsA patients (28 male and 30 female) and tested by PCR-SSP (Polymerase Chain Reaction - Sequence Specific Primers) method for polymorphism of the above mentioned HLA loci. The strongest association between psoriatic arthritis and HLA in the Croatian population was observed for alleles at HLA-B locus (B*39 and B*57), while the association of B*27 and B*13 alleles with PsA reached significance only before correction of p value with the number of tested alleles. Higher frequency of Cw*02 and DRB1*16 alleles is a result of linkage disequilibrium between these alleles and HLA-B alleles associated with PsA in Croatia. We also observed lower frequency of B*0702, B*18 and B*38 alleles in our group of patients

The role of IGF-1 (CA)n polymorphism on peak bone mass attainment in males

Cilj: Idiopatska osteoporoza u muškaraca prvenstveno je posljedica niske vršne koštane mase koja je genetski uvjetovana. S obzirom na njegovu važnu ulogu u metabolizmu kosti, između brojnih gena kandidata u patogenezi osteoporoze, od posebnog je interesa gen za čimbenik rasta sličan inzulinu (IGF-1). Prethodna istraživanja pokazala su da je polimorfizam mikrosatelitne regije citozin-adenin (CA)n unutar gena za IGF-1 povezan sa serumskom koncentracijom IGF-I, stoga je primarni cilj ovog istraživanja bio analizirati utjecaj ovog polimorfizma na vršnu koštanu masu u muškaraca. Metode: U istraživanje su uključena 92 zdrava muškarca u dobi od 21 do 35 godina. Svakom je ispitaniku izmjerena mineralna gustoća kosti (BMD) u lumbalnoj kralježnici i proksimalnom dijelu bedrene kosti, koncentracije biljega koštane pregradnje, 25-OHD i spolnih hormona. Rezultati: Ispitanici u kojih je nađen alel (CA)18 (genotip 18+) imali su niži BMD u svim mjerenim područjima, no razlike između ispitivanih skupina nisu bile statistički značajne. Ipak, u homozigota (CA)18 nađen je značajno niži BMD u području vrata bedrene kosti (P=0,03), trohantera (P=0,01) i proksimalnog dijela bedrene kosti (P=0,04), dok razlike u koncentracijama biljega koštane pregradnje, 25-OHD, slobodnog testosterona i estradiola nisu bile statistički značajne. Rasprava: Rezultati ovog istraživanja ukazali su na mogući negativan utjecaj alela IGF-1 (CA)18 na vršnu koštanu masu u muškaraca. Ipak, za definitivne zaključke o ulozi tog polimorfizma u patogenezi osteoporoze potrebna su daljnja istraživanja na većem broju ispitanika i u različitim populacijama.Aim: Idiopathic osteoporosis in males is influenced predominantly by low peak bone mass as a feature under a strong genetic control. Among number of candidate genes, IGF-1 gene is of particular interest due to its important role in bone metabolism. It has been reported that IGF-1 citozin-adenin (CA)n polymorphism is related to serum IGF-1 concentration. Therefore, in the present study we examined the influence of certain IGF-1 (CA)n alleles on peak bone mass attainment in males. Methods: Study sample consisted of 92 unrelated healthy male volunteers, aged 21-35. In each subject, lumba spine and proximal femur bone mineral density (BMD), bone turnover markers, 25-OHD and sex hormones levels were measured. Results: IGF-1 (CA)18 allele (genotype 18+) were found to be �associated with low-lower BMD in all measured areas but the differences between analysed groups were not significant. However, homozygotes (CA)18 had significantly lower femoral neck (P=0,03), trochanter (P=0,01) and total hip (P=0,04) BMD whereas differences in bone turnover markers, 25-OHD, free testosterone and estradiol concentrations were not significant. Discussion: The results of the present study suggested possible negative effect of the IGF-1 (CA)18 allele on the peak bone mass attainment in males. However, for definitive conclusion about the role of this polymorphism in the pathogenesis of osteoporosis further studies in different populations and with larger number of participants are needed

The role of IGF-1 (CA)n polymorphism on peak bone mass attainment in males

Cilj: Idiopatska osteoporoza u muškaraca prvenstveno je posljedica niske vršne koštane mase koja je genetski uvjetovana. S obzirom na njegovu važnu ulogu u metabolizmu kosti, između brojnih gena kandidata u patogenezi osteoporoze, od posebnog je interesa gen za čimbenik rasta sličan inzulinu (IGF-1). Prethodna istraživanja pokazala su da je polimorfizam mikrosatelitne regije citozin-adenin (CA)n unutar gena za IGF-1 povezan sa serumskom koncentracijom IGF-I, stoga je primarni cilj ovog istraživanja bio analizirati utjecaj ovog polimorfizma na vršnu koštanu masu u muškaraca. Metode: U istraživanje su uključena 92 zdrava muškarca u dobi od 21 do 35 godina. Svakom je ispitaniku izmjerena mineralna gustoća kosti (BMD) u lumbalnoj kralježnici i proksimalnom dijelu bedrene kosti, koncentracije biljega koštane pregradnje, 25-OHD i spolnih hormona. Rezultati: Ispitanici u kojih je nađen alel (CA)18 (genotip 18+) imali su niži BMD u svim mjerenim područjima, no razlike između ispitivanih skupina nisu bile statistički značajne. Ipak, u homozigota (CA)18 nađen je značajno niži BMD u području vrata bedrene kosti (P=0,03), trohantera (P=0,01) i proksimalnog dijela bedrene kosti (P=0,04), dok razlike u koncentracijama biljega koštane pregradnje, 25-OHD, slobodnog testosterona i estradiola nisu bile statistički značajne. Rasprava: Rezultati ovog istraživanja ukazali su na mogući negativan utjecaj alela IGF-1 (CA)18 na vršnu koštanu masu u muškaraca. Ipak, za definitivne zaključke o ulozi tog polimorfizma u patogenezi osteoporoze potrebna su daljnja istraživanja na većem broju ispitanika i u različitim populacijama.Aim: Idiopathic osteoporosis in males is influenced predominantly by low peak bone mass as a feature under a strong genetic control. Among number of candidate genes, IGF-1 gene is of particular interest due to its important role in bone metabolism. It has been reported that IGF-1 citozin-adenin (CA)n polymorphism is related to serum IGF-1 concentration. Therefore, in the present study we examined the influence of certain IGF-1 (CA)n alleles on peak bone mass attainment in males. Methods: Study sample consisted of 92 unrelated healthy male volunteers, aged 21-35. In each subject, lumba spine and proximal femur bone mineral density (BMD), bone turnover markers, 25-OHD and sex hormones levels were measured. Results: IGF-1 (CA)18 allele (genotype 18+) were found to be �associated with low-lower BMD in all measured areas but the differences between analysed groups were not significant. However, homozygotes (CA)18 had significantly lower femoral neck (P=0,03), trochanter (P=0,01) and total hip (P=0,04) BMD whereas differences in bone turnover markers, 25-OHD, free testosterone and estradiol concentrations were not significant. Discussion: The results of the present study suggested possible negative effect of the IGF-1 (CA)18 allele on the peak bone mass attainment in males. However, for definitive conclusion about the role of this polymorphism in the pathogenesis of osteoporosis further studies in different populations and with larger number of participants are needed

Utjecaj polimorfizma mikrosatelitnog lokusa (CA)n unutar gena za IGF-1 na vršnu koštanu masu u muškaraca

Aim: Idiopathic osteoporosis in males is influenced predominantly by low peak bone mass as a feature under a strong genetic control. Among number of candidate genes, IGF-1 gene is of particular interest due to its important role in bone metabolism. It has been reported that IGF-1 citozin-adenin (CA)n polymorphism is related to serum IGF-1 concentration. Therefore, in the present study we examined the influence of certain IGF-1 (CA)n alleles on peak bone mass attainment in males. Methods: Study sample consisted of 92 unrelated healthy male volunteers, aged 21-35. In each subject, lumba spine and proximal femur bone mineral density (BMD), bone turnover markers, 25-OHD and sex hormones levels were measured. Results: IGF-1 (CA)18 allele (genotype 18+) were found to be �associated with low-lower BMD in all measured areas but the differences between analysed groups were not significant. However, homozygotes (CA)18 had significantly lower femoral neck (P=0,03), trochanter (P=0,01) and total hip (P=0,04) BMD whereas differences in bone turnover markers, 25-OHD, free testosterone and estradiol concentrations were not significant. Discussion: The results of the present study suggested possible negative effect of the IGF-1 (CA)18 allele on the peak bone mass attainment in males. However, for definitive conclusion about the role of this polymorphism in the pathogenesis of osteoporosis further studies in different populations and with larger number of participants are needed.Cilj: Idiopatska osteoporoza u muškaraca prvenstveno je posljedica niske vršne koštane mase koja je genetski uvjetovana. S obzirom na njegovu važnu ulogu u metabolizmu kosti, između brojnih gena kandidata u patogenezi osteoporoze, od posebnog je interesa gen za čimbenik rasta sličan inzulinu (IGF-1). Prethodna istraživanja pokazala su da je polimorfizam mikrosatelitne regije citozin-adenin (CA)n unutar gena za IGF-1 povezan sa serumskom koncentracijom IGF-I, stoga je primarni cilj ovog istraživanja bio analizirati utjecaj ovog polimorfizma na vršnu koštanu masu u muškaraca. Metode: U istraživanje su uključena 92 zdrava muškarca u dobi od 21 do 35 godina. Svakom je ispitaniku izmjerena mineralna gustoća kosti (BMD) u lumbalnoj kralježnici i proksimalnom dijelu bedrene kosti, koncentracije biljega koštane pregradnje, 25-OHD i spolnih hormona. Rezultati: Ispitanici u kojih je nađen alel (CA)18 (genotip 18+) imali su niži BMD u svim mjerenim područjima, no razlike između ispitivanih skupina nisu bile statistički značajne. Ipak, u homozigota (CA)18 nađen je značajno niži BMD u području vrata bedrene kosti (P=0,03), trohantera (P=0,01) i proksimalnog dijela bedrene kosti (P=0,04), dok razlike u koncentracijama biljega koštane pregradnje, 25-OHD, slobodnog testosterona i estradiola nisu bile statistički značajne. Rasprava: Rezultati ovog istraživanja ukazali su na mogući negativan utjecaj alela IGF-1 (CA)18 na vršnu koštanu masu u muškaraca. Ipak, za definitivne zaključke o ulozi tog polimorfizma u patogenezi osteoporoze potrebna su daljnja istraživanja na većem broju ispitanika i u različitim populacijama