Association of hereditary elliptocytosis and Gilbert’s syndrome as the cause of biliary calculosis: Case report

Introduction. Biliary calculosis is rare in children. It occurs associated with different haemolytic and non-haemolytic disorders, which are sometimes also combined. Case Outline. A 15-year-old male was hospitalized due to biliary calculosis and non-conjugated hyper-bilirubinemia. A mild non-conjugated hyperbilirubinemia, without anaemia and other symptoms of liver dysfunction, was registered at age 8 years, and 7 years later cholelithiasis with transitory choledocholithiasis. The finding of ellyptocytes in blood smear, which was also verified in mother, normal haemoglobin count and the absence of diseases followed by secondary dysmorphic erythrocytes of this type, indicated a clinically milder (compensated) hereditary ellyptocytosis, while more than a double increase of non-conjugated serum bilirubin fracture after a three-day hypocaloric diet (400 kcal per day) showed the concurrent presence of Gilbert’s syndrome. In the laparascopically removed gallbladder a larger number of small pigmented calculi were disclosed. Conclusion. Gilbert’s syndrome is an essential precipitating factor of biliary calculosis in patients with chronic haemolytic condition. Thus, in all cases of biliary calculosis and non-conjugated hyperbilirubinemia with absent clinical and laboratory parameters of liver disorders and anaemia, except in compensated haemolytic disease and Gilbert’s syndrome as isolated disorders, a possibility of their association should be taken into consideration

Rapid characterization of b-thalassemia mutations by reverse dot blot and allele-specific pcr analysis

U ovom radu je prikazan slučaj b-talasemije major čija je dijagnoza postavljena na molekularnom nivou korišćenjem modernih metoda molekularne genetike. Ovaj primer ilustruje strategiju koju smo izabrali da bi se detektovale b-talasemijske mutacije u R Srbiji, a u cilju sprovođenja skrininga u našoj populaciji prenatalne dijagnostike u rizičnim porodicama. Za analizu genomske DNK izolovane iz krvi pacijenta sa kliničkom slikom talasemije major, korišćene su metode reverznog dot blota (RDB) i alel-specifičnog PCR-a (ARMS). Pokazano je da je pacijent dvostruki heterozigot za b-talasemijske mutacije: b+IVSI-110 i b+IVSI-6.This paper reports a case of b-thalassaemia major whose molecular diagnosis was achieved by using modern methods of molecular genetics. This example demonstrates the strategy we chose to detect b-thalassaemia mutations in the Republic of Serbia in order to complete molecular screening in our population and to make prenatal diagnosis in pregnancies at risk. The analysis of genomic DNA isolated from the blood of patient affected with thalassaemia major is carried out by the methods: RDB (reverse dot blot) and ARMS (amplification refractory mutation system). It is shown that the patient is a compound heterozygote for two b- -thalassaemic mutations: b+IVSI-110 and b+IVSI-6

Next generation sequencing as a tool for pharmacogenomic profiling: Nine novel potential genetic markers for targeted therapy in childhood acute lymphoblastic leukemia

Uvod/Cilj Sekvenciranje nove generacije (SNG) omogućilo je genomsko profilisanje svakog bolesnika. Nova saznanja u oblasti farmakogenomike omogućavaju primenu podataka dobijenih ovom metodom u cilju otkrivanja novih mogućih genetičkih markera za ciljanu terapiju mnogih, posebno malignih bolesti. Cilj ovog istraživanja je bio da se primenom SNG odre- di genetski profil akutne limfoblastne leukemije (ALL) kod dece u cilju procene mogućih molekularnih meta za ciljanu terapiju. Metode Analizirali smo DNK uzorke 17 bolesnika obolelih od ALL dečjeg doba koristeći ciljano SNG. Napredne bioinformatičke metode su korišćene da identifikuju nove mutacije u analiziranim genima i da predvide njihov uticaj i farmakogenomski potencijal. Rezultati Identifikovali smo devet genskih varijanti koje do sada nisu opisane u relevantnim bazama podataka. U navedenim varijantama identifikovane su dve 'besmislene' varijante, ABL1 p.Q252* i AKT1 p.W22*, jedna varijanta koja pomera okvir čitanja, STK11 p.G257fs*28, i šest nesinonimnih varijanti. Kreirali smo trodimenzionalni model za četiri proteina koji bi bili produkt novih nesinonimnih varijanti. Analizirali smo farmakogenomski potencijal svake varijante i otkrili da su dve, STK11 c.1023G gt T/ p.L341F i ERBB2 c.2341C gt T/ p.R781W, mogući kandidati za ciljanu terapiju. Zaključak Nove varijante otkrivene u ovoj studiji pripa- daju uglavnom genima povezanim sa Ras signalnim putem, koji je često zahvaćen mutacijama u ALL kod dece. Farmakogenomsko profilisanje svake dečje ALL biće nezamenljivo za nove terapijske pristupe. Detekcija i inicijalna analiza novih genskih varijanti, koja je predstavljena u ovoj studiji, postaće standardna procedura za dizajniranje i razvoj individualizovane terapije za decu obolelu od ALL.Introduction/Objective Next generation sequencing (NGS) technology has enabled genomic profiling of each patient. Growing knowledge in pharmacogenomics makes it possible to use NGS data for discovery of novel potential genetic markers for targeted therapy of many diseases, especially cancers. The aim of this study was to use targeted NGS to make a genetic profile of childhood acute lymphoblastic leukemia (cALL) in order to evaluate potential molecular targets for targeted therapy. Methods We analyzed DNA samples from 17 cALL patients using NGS targeted sequencing. Advanced bioinformatic analysis was used to identify novel mutations in analyzed genes and to predict their effect and pharmacogenomic potential. Results We identified nine variants that have not been previously reported in relevant databases, including two stop-gain variants, ABL1 p.Q252* and AKT1 p.W22*, one frameshift, STK11 p.G257fs*28, and six missense variants. We created three-dimensional models of four proteins harboring novel missense variants. We analyzed pharmacogenomic potential of each variant and found that two of them, STK11 c.1023G gt T/ p.L341F and ERBB2 c.2341C gt T/ p.R781W, are suitable candidates for targeted therapy. Conclusion Most new variants detected in this study were found in the genes associated with Ras signaling pathway, which is frequently mutated in cALL patients. Pharmacogenomic profiling of each cALL will be indispensable for novel therapy approaches. Detection and initial analysis of novel variants, presented in this study, will become a standard procedure for the design and development of individualized therapies for children with ALL, leading to improved patient outcomes

Importance of genotyping of Thiopurine S-methyltransferase in children with acute lymphoblastic leukaemia during maintenance therapy

Uvod. Tiopurin-S-metiltransferaza (TPMT ) je enzim koji katalizuje inaktivaciju merkaptopurina, leka koji se široko primenjuje u lečenju akutne limfoblastne leukemije (ALL) kod dece. Kada se osobe s nedostatkom TPMT leče standardnim dozama merkaptopurina, kod njih se razvija teška i po život opasna mijelotoksičnost. Cilj rada. Cilj rada je bio da se utvrdi da li kod dece s ALL koji su nosioci mutacije u genu za TPMT individualizovanjem doziranja merkaptopurina može da se smanji mijelotoksičnost terapije, te da li broj tandemskih ponovaka (engl. variable number of tandem repeats - VNTR) u promotoru gena za TPMT ima uticaja na efekte terapije merkaptopurinom. Metod rada Metodima lančane reakcije umnožavanja DNK (engl. polymerase chain reaction - PCR) ispitano je 50 nasumično odabrane dece lečene ALL IC-BFM 2002 protokolom na najčešće mutacije u genu za TPMT. Za 20 dece je PCR metodima određen VNTR genotip. Ispitanicima je tokom faze održavanja beležen broj nedelja kada su terapiju dobijali u punim ili smanjenim dozama, kao i broj nedelja bez terapije. Rezultati Među 50 dece bilo je 29 dečaka (58%) i 21 (42%) devojčica, uzrasta od 1,8 do 17,3 godine (medijana 6,2 godine). Utvrđeno je četvoro (8%) heterozigotnih nosilaca mutacija, kod kojih je otkrivena TPMT*3A varijanta. Posle 12, 14, 16 i 19 nedelja lečenja smanjenim dozama merkaptopurina bolesnici su, zbog dobrog podnošenja terapije, postepeno počeli da primaju punu dozu leka. Nije bilo odlaganja terapije. Smanjenje kumulativne doze merkaptopurina za bolesnike sa TPMT mutacijama bilo je 7,8%, 7,4%, 11,2% i 16,6%. Između dece bez TPMT mutacija i heterozigota nije za- beležena statistički značajna razlika u trajanju lečenja punim (53,6 nasuprot 55,7 nedelja) i smanjenim dozama merkaptopurina (19,9 nasuprot 15,2 nedelje). Otkrivenih VNTR bilo je između četiri i sedam. Većina bolesnika imala je različit broj VNTR na homolognim hromozomima. Najčešće uočen polimorfizam bio je VNTR*5. Nije zabeležena korelacija između nasleđivanja TPMT i VNTR genotipa. Zaključak Farmakogenetskim principima u lečenju ALL dece može se postići napredak u podnošenju lečenja merkaptopurinom.INTRODUCTION Thiopurine S-methyltransferase (TPMT) is an enzyme that catalyses the inactivation of mercaptopurine (MP) which is widely used in the treatment of acute lymphoblastic leukaemia (ALL) of childhood. Potentially fatal myelotoxicity may develop after standard doses of MP in TPMT deficient patients. OBJECTIVES To establish if individually tailored doses of MP can reduce myelotoxicity in ALL patients carrying mutations in the TPMT gene. To establish if variable number of tandem repeats (VNTR) genotype influences the treatment effects of MP. METHOD Fifty randomly selected patients treated according to ALL IC-BFM 2002 protocol were tested for most frequent TPMT gene mutations using PCR based methods. VNTR genotype was determined in 20 children by PCR methods. During the maintenance phase, we recorded the number of weeks when therapy was applied in either full doses, reduced doses or when patients were without any therapy. RESULTS Fifty children were examined, 29 boys (58%) and 21 girls (42%); age ranged from 1.8-17.3 years (median 6.2 years). Four patients (8%) were heterozygous for TPMT mutations, all of them carrying the TPMT*3A variant. After 12, 14, 16 and 19 weeks of therapy with reduced doses of MP, the patients switched to full doses due to good tolerance. There was no therapy omission. Cumulative dose of MP was reduced for 7.8%, 7.4%, 11.2% and 16.6%, respectively, in patients with TPMT mutations. No significant difference was found between children with no mutations and TPMT heterozygotes regarding full dose therapy (53.6 vs. 55.7 weeks, respectively) and reduced dose therapy (19.9 vs. 15.2 weeks respectively). The number of detected VNTRs ranged from four to seven. The majority of patients had different number of VNTRs on homologous chromosomes. Most frequently detected polymorphism was VNTR*5. No correlation was found between TPMT and VNTR genotype inheritance. CONCLUSION Obeying pharmacogenetic principles in the treatment of childhood ALL may improve the tolerance of therapy with MP

Immunoglobulin heavy chain gene rearrangements in patients with Gaucher disease

Uvod: Nekoliko studija u literaturi navode dokaze o povećanoj incidenci hematoloških komplikacija u bolesnika sa Gošeovom bolešću, uključujući monoklonsku i poliklonsku gamapatiju i hematološke malignitete, a posebno multipli mijelom. Metode: Određivana je serumska koncentracija imunoglobulina kao i rearanžman gena za teški lanac imunoglobulina - IGH, PCR analizom. Klonalni PCR produkti su direktno sekvencirani i analizirani koristeći adekvatne alate i baze podataka. Monoklonski proteini seruma su detektovani i identifikovani metodom elektroforeze. Rezultati: Među 27 bolesnika, klonalni IGH rearanžman je otkriven kod osmoro, od kojih je petoro imalo i monot klonski protein u serumu. Hipergamaglobulinemija je otkrivena u 9/27 bolesnika. Podaci o praćenju za 17 bolesnika su pokazali da je klonalni rearanžman ostao isti u četiri bolesnika, dok je u jednog bolesnika iščezao tokom perioda praćenja. Preostalih 12/17 bolesnika nisu imali klonalni IGH rearanžman niti su ga stekli nakon perioda praćenja. Zaključak: Iako klonska ekspanzija može da nastane relativno rano u toku Gošeove bolesti, barem sudeći prema rearanžmanu IGH gena, detektovani klonovi mogu biti tranzitorni. Pažljivo kliničko praćenje ovih bolesnika je obavezno, uključujući i nadzor nad limfoidnim neoplazmama, posebno multiplim mijelomom.Background: Several studies support the evidence of increased incidence of hematological complications in Gaucher disease including monoclonal and polyclonal gammopathies and blood malignancies, especially multiple myeloma. Methods: Serum concentrations of immunoglobulins and PCR analysis of the IGH gene rearrangements were performed. The clonal PCR products were directly sequenced and analyzed with the appropriate database and tools. Serum monoclonal proteins were detected and identified by electrophoresis. Results: Among 27 Gaucher patients, clonal IGH rearrangement was discovered in eight, with 5/8 having also serum monoclonal protein. Elevated immunoglobulins were detected in 9/27 patients. Follow-up data for 17 patients showed that the clonal rearrangement remained the same in four of them, however, in one patient it disappeared after the follow-up period. The remaining 12/17 patients were without previous IGH clonal rearrangement and remained so after the follow-up. Conclusions: Although clonal expansion may occur relatively early in the disease course, at least judging by the IGH gene rearrangements in Gaucher patients, the detected clones may be transient. A careful clinical follow-up in these patients is mandatory, including monitoring for lymphoid neoplasms, especially multiple myeloma

Pharmacogenomic Markers of Methotrexate Response in the Consolidation Phase of Pediatric Acute Lymphoblastic Leukemia Treatment

Methotrexate (MTX) is one of the staples of pediatric acute lymphoblastic leukemia (ALL) treatment. MTX targets the folate metabolic pathway (FMP). Abnormal function of the enzymes in FMP, due to genetic aberrations, leads to adverse drug reactions. The aim of this study was to investigate variants in pharmacogenes involved in FMP and their association with MTX pharmacokinetics (MTX elimination profile) and toxicity in the consolidation therapy phase of pediatric ALL patients. Eleven variants in the thymidylate synthetase (TYMS), methylenetetrahydrofolate reductase (MTHFR), dihydrofolate reductase (DHFR), SLC19A1 and SLCO1B genes were analyzed in 148 patients, using PCR- and sequencing-based methodology. For the Serbian and European control groups, data on allele frequency distribution were extracted from in-house and public databases. Our results show that the A allele of SLC19A1 c.80 variant contributes to slow MTX elimination. Additionally, the AA genotype of the same variant is a predictor of MTX-related hepatotoxicity. Patients homozygous for TYMS 6bp deletion were more likely to experience gastrointestinal toxicity. No allele frequency dissimilarity was found for the analyzed variants between Serbian and European populations. Statistical modelling did not show a joint effect of analyzed variants. Our results indicate that SLC19A1 c.80 variant and TYMS 6bp deletion are the most promising pharmacogenomic markers of MTX response in pediatric ALL patients

Immunoglobulin genes and T-cell receptors as molecular markers in children with acute lymphoblastic leukaemia

Uvod. Akutna limfoblastna leukemija (ALL) je maligna klonalna bolest i jedna od najčešćih neoplazmi dečjeg uzrasta. Primenom savremenih protokola postižu se visok stepen remisije i dugogodišnja stopa preživljavanja. Uvođenjem metoda molekularne genetike omogućeni su submikroskopska klasifikacija i praćenje minimalne rezidualne bolesti (MRB), odgovorne za nastanak recidiva. Cilj rada. Cilj rada je bilo ispitivanje učestalosti rearanžmana genskih lokusa za teške lance imunoglobulina (IgH) i T-ćelijski receptor (TCR) i njihova korelacija s kliničkim parametrima. Metode rada. Ispitano je 41 dete obolelo od ALL kojima je na dijagnozi rađena molekularna detekcija rearanžmana genskih lokusa za IgH i TCR metodom lančanog umnožavanja DNK (PCR). Posmatranje razvoja MRB je rađeno u indukcionoj fazi lečenja, kada se očekuje morfološki odgovor na terapiju. Rezultati. Rearanžman genskog lokusa za IgH zabeležen je kod 82,9%, a za TCR kod 56,1% ispitanika. Posle 33 dana indukcione terapije rearanžmani za IgH genski lokus su zabeleženi kod 39%, a za TCR kod 36,5% dece. Zaključak. Otkrivanje genetskih aberacija na molekularnom nivou i njihova korelacija sa standardnim prognostičkim parametrima ukazala je na značaj nove stratifikacije rizičnih grupa, koje zahtevaju promenu intenziteta hemioterapije. Praćenje MRB se pokazalo preciznim prediktivnim faktorom u nastanku recidiva bolesti. PR Projekat Ministarstva nauke Republike Srbije, br. 143051.Introduction. Acute lymphoblastic leukaemia (ALL) is a malignant clonal disease, one of the most common malignancies in childhood. Contemporary protocols ensure high remission rate and long term free survival. The ability of molecular genetic methods help to establish submicroscopic classification and minimal residual disease (MRD) follow up, in major percent responsible for relapse. Objective. The aim of the study was to detect the frequency of IgH and TCR gene rearrangements and their correlation with clinical parameters. Methods. Forty-one children with ALL were enrolled in the study group, with initial diagnosis of IgH and TCR gene rearrangements by polimerase chain reaction ( PCR). MRD follow-up was performed in induction phase when morphological remission was expected, and after intensive chemiotherapy. Results. In the study group IgH rearrangement was detected in 82.9% of children at the diagnosis, while TCR rearrangement was seen in 56.1%. On induction day 33, clonal IgH rearrangements persisted in 39% and TCR rearrangements in 36.5% of children. Conclusion. Molecular analysis of genetic alterations and their correlation with standard prognostic parameters show the importance of risk stratification revision which leads to new therapy intensification approach. MRD stands out as a precise predictive factor for the relapse of disease

Wilms tumor (wt)1 gene expression in children with acute leukemia in Serbia

Acute leukemias constitute the most common malignancy in childhood, accounting for 25-35% of all cancer in children. They are divided into acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Genetic susceptibility is known to play a major role in childhood leukemias. Wilms tumor (WT)1 is a zinc finger transcription factor involved in regulating the process of cell differentiation; it has been implicated in a wide range of human neoplasms. WT1 overexpression in the bone marrow at diagnosis is reported to be an independent negative prognostic factor in adults and children with AML. The aim of the present investigation was to determine the expression of WT1 in the bone marrow of children with AML and ALL in Serbia and its possible impact on patient survival. We determined bone marrow WT1 expression levels by reverse -transcription polymerase chain reaction (RT-PCR) at diagnosis in 20 children with AML and 20 children with ALL (16 B-ALL and 4 T-ALL), as well as 15 age- and sex-matched controls who were evaluated for immune thrombocytopenic purpura (ITP). For children with AML, follow-up samples were also analyzed one month after treatment initiation and at variable later timepoints of control punctures. The results were normalized based on WT1 expression in controls. We found that children with AML had significantly higher WT1 expression at diagnosis (median SD: 139.42 244.03) than those with ALL (1.18 54.37; Mann -Whitney U=82; p lt 0.01) and ITP (0.76 1.01; U=32; p lt 0.01). Patients with T-ALL had higher WT1 expression than those with B-ALL, though significance was not reached due to subgroup size; differences between AML subgroups according to the French-American-British (FAB) classification were also below the level of significance, though a tendency toward higher values in M3 and M4 leukemias was notable. There was also a tendency toward higher values in 14 children with AML who were still alive after a median follow-up of 1.5 years (181.42 192.52) than in 6 who succumbed to the disease (104.29 354.87). All children with AML who had WT1 expression 1 month after diagnosis below the fourth quartile (10 of 10) were still alive, while only 2 of 5 with 1 -month WT1 expression in the fourth quartile survived (Fisher's exact test: p=0.0952). Taken together, our results support a role for WT1 in the diagnostic workup in children with acute leukemia, although it needs to be considered in view of a complex and indvidualized context

Pharmacogenomic markers of glucocorticoid response in the initial phase of remission induction therapy in childhood acute lymphoblastic leukemia

Background. Response to glucocorticoid (GC) monotherapy in the initial phase of remission induction treatment in childhood acute lymphoblastic leukemia (ALL) represents important biomarker of prognosis and outcome. We aimed to study variants in several pharmacogenes (NR3C1, GSTs and ABCB1) that could contribute to improvement of GC response through personalization of GC therapy. Methods. Retrospective study enrolling 122 ALL patients was carried out to analyze variants of NR3C1 (rs33389, rs33388 and rs6198), GSTT1 (null genotype), GSTM1 (null genotype), GSTPI (rs1695 and rs1138272) and ABCB1 (rs1128503, rs2032582 and rs1045642) genes using PCR-based methodology. The marker of GC response was blast count per microliter of peripheral blood on treatment day 8. We carried out analysis in which cut-off value for GC response was 1000 (according to Berlin-Frankfurt-Munster [BFM] protocol), as well as 100 or 0 blasts per microliter. Results. Carriers of rare NR3C1 rs6198 GG genotype were more likely to have blast count over 1000, than the noncarriers (p = 0.030). NR3C1 CAA (rs33389-rs33388-rs6198) haplotype was associated with blast number below 1000 (p = 0.030). GSTP1 GC haplotype carriers were more likely to have blast number below 1000 (p = 0.036), below 100 (p = 0.028) and to be blast negative (p = 0.054), while GSTP1 GT haplotype and rsl 138272 T allele carriers were more likely to be blasts positive (p = 0.034 and p = 0.024, respectively). ABCB1 CGT (rs1128503-rs2032582-rs1045642) haplotype carriers were more likely to be blast positive (p = 0.018). Conclusions. Our results have shown that NR3C1 rs6198 variant and GSTP1 rs1695-rs1138272 haplotype are the most promising pharmacogenomic markers of GC response in ALL patients

Importance of pharmacogenetic markers in the methylenetetrahydrofolate reductase gene during methotrexate treatment in pediatric patients with acute lymphoblastic leukemia

Despite remarkable progress in survival of children with acute lymphoblastic leukemia (ALL) which has reached about 85%, early toxicity and relapse rate remain issues that need to to be resolved. Genetic variants are important factors influencing the metabolism of cytotoxic drugs in ALL treatment. Variants in genes coding for methotrexate (MTX)-metabolizing enzymes are under constant scientific interest due to their potential impact on drug toxicity and relapse rate. We investigated methylenetetrahydrofolate reductase (MTHFR) c.677C gt T and MTHFR c.1298A gt C variants as pharmacogenetic markers of MTX toxicity and predictors of relapse. The study enrolled 161 children with ALL, treated according to the current International Berlin-Frankfurt-Munster group (BFM) for diagnostics and treatment of leukemia and lymphoma protocols. Genotyping was performed using PCR-RFLP and allele-specific PCR assays. Our results revealed similar distributions of MTHFR c.677C gt T and MTHFR c.1298A gt C genotypes among 104 healthy individuals as compared to pediatric ALL patients. A lower incidence of early MTX toxicity was noted in the MTHFR c.677TT genotype (p=0.017), while MTHFR c.1298A gt C genotypes were not associated with MTX toxicity. Carriers of any MTHFR c.677C gt T and MTHFR c.1298A gt C genotypes did not experience decreased overall survival (OAS) or higher relapse rates. Genetic variants in the MTHFR gene are not involved in leukemogenesis in pediatric ALL. The presence of the MTHFR c.677TT genotype was recognized as a predictive factor for decreased MTX toxicity during the intensification phase of therapy. Neither MTHFR c.677C gt T nor MTHFR c.1298A gt C genotypes correlated with an increased number of toxic deaths or relapse rate. Our study emphasizes the importance of implementing pharmacogenetic markers in order to optimize pediatric ALL therapy