Determining T and B Cell development by TREC/KREC analysis in primary immunodeficiency patients and healthy controls.

T cell receptor excision circles (TRECs) and kappa-deleting excision circles (KRECs) are DNA fragments potentially indicative of T and B cell development, respectively. Recent thymic emigrants (RTEs) are a subset of peripheral cells that may also represent thymic function. Here, we investigated TREC/KREC copy numbers by quantitative real-time PCR in the peripheral blood of patients with primary immunodeficiencies (PIDs, n = 145) and that of healthy controls (HCs, n = 86) and assessed the correlation between RTEs and TREC copy numbers. We found that TREC copy numbers were significantly lower in children and adults with PIDs (P < .0001 and P < .002, respectively) as compared with their respective age-matched HCs. A moderate correlation was observed between TREC copies and RTE numbers among children with PID (r = .5114, P < .01), whereas no significant correlation was detected between RTE values and TREC content in the HCs (r = .0205, P = .9208). Additionally, we determined TREC and KREC copy numbers in DNA isolated from the Guthrie cards of 200 newborns and showed that this method is applicable to DNA isolated from both peripheral blood samples and dried blood spots, with the two sample types showing comparable TREC and KREC values. We further showed that RTE values are not always reliable markers of T cell output. Although additional confirmatory studies with larger cohorts are needed, our results provide thresholds for TREC/KREC copy numbers for different age groups.

A novel germline Pregnane X Receptor (PXR) variant predisposing to Hodgkin lymphoma in two siblings.

Hodgkin's lymphoma (HL) is the most common cancer in adolescents and young adults. A family history of HL increases the risk of developing HL in other family members. Identification of genetic predisposition variants in HL is important for understanding disease aetiology, prognosis, and response to treatment. Aberrant activation of the NF-κB pathway is a hallmark feature of HL, contributing to the survival and proliferation of the malignant cells' characteristic of HL. The family with multiple consanguineous marriages with siblings of diagnosed HL was examined by whole-exome sequencing. We found a germline homozygous variation in the PXR ligand binding domain (NM_003889.3:c.811G>A, p.(Asp271Asn)), which was classified as pathogenic by prediction tools and segregated in HL cases. Increased PXR expression was found in homozygous variant carriers compared to heterozygous carriers by quantitative real time PCR (qRT-PCR) and immunofluorescence staining of patients' formalin-fixed paraffin-embedded tissues showed upregulation of PXR, particularly in Hodgkin Reed/Sternberg (HRS) cells. Patients with homozygous PXR variant showed significantly high expression compared to PXR wild-type HL, heterozygous and controls (p = 0.0001, p = 0.0004 and p = 0.0001, respectively). PXR homozygous HRS cells had significantly higher PXR expression compared to PXR wild-type HRS cells (p < 0.0001, 3.27-fold change). Albeit PXR's prominent expression in cytoplasm of HRS cells, homozygous PXR HRS cells showed increased PXR expression in nucleus (p < 0.001). PXR is a member of the nuclear receptor superfamily and previous studies have demonstrated a pleiotropic effect of PXR on malignant transformation. Expression analysis showed that cell proliferation, apoptosis and inflammation related genes were deregulated, in homozygous PXR HL cases. This study provided clinical evidence to previously reported Sxr-/- mice model that develop multifocal lymphomas, had an aberrantly increased NF-κB expression and consistent inflammation. Further functional studies are needed to elucidate the exact mechanisms of action of PXR in HL pathogenesis.

A Genetic Assessment of Dopamine Agonist-Induced Impulse Control Disorder in Patients With Prolactinoma.

CONTEXT: Dopamine agonist (DA)-induced impulse control disorder (ICD) represents a group of behavioral disorders that are increasingly recognized in patients with prolactinoma. OBJECTIVE: We aimed to examine the genetic component of the underlying mechanism of DA-induced ICD. METHODS: Patients with prolactinoma receiving dopamine agonist (cabergoline) treatment were included in the study. These patients were divided into 2 groups: patients who developed ICD due to DA and patients who did not. Patients were evaluated for polymorphisms of the DRD1, DRD3, COMT, DDC, GRIN2B, TPH2, OPRK1, OPRM1, SLC6A4, SLC6A3, HTR2A genes. RESULTS: Of the 72 patients with prolactinoma using cabergoline, 20 were diagnosed with ICD. When patients with and without ICD were compared according to genotype frequencies, OPRK1/rs702764, DRD3/rs6280, HTR2A/rs6313, SLC6A4/rs7224199, GRIN2B/rs7301328, TPH2/rs7305115, COMT/rs4680, DRD1/rs4532 polymorphisms significantly increased in patients with DA-induced ICD. CONCLUSION: Our results show that multiple neurotransmission systems affect DA-induced ICD in patients with prolactinoma.

Zinc finger protein 384 (ZNF384) impact on childhood mixed phenotype acute leukemia and B-cell precursor acute lymphoblastic leukemia.

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a heterogeneous malignancy and consists of several genetic abnormalities. Some of these abnormalities are used in clinics for risk calculation and treatment decisions. Patients with ZNF384 rearrangements had a distinct expression profile regardless of their diagnosis, BCP-ALL or mixed phenotype acute leukemia (MPAL) and defined as a new subtype of ALL. In this study, we screened 42 MPAL and 91 BCP-ALL patients for the most common ZNF384 fusions; ZNF384::TCF3, ZNF384::EP300 and ZNF384::TAF15 by using PCR. We identified ZNF384 fusions in 9.5% of MPAL and 7.6% of BCP-ALL. A novel breakpoint was identified in ZNF384::TCF3 fusion in one BCP-ALL patient. T-myeloid MPAL patients showed significantly lower ZNF384 expression compared to lymphoid groups. Patients with ZNF384r had intermediate survival rates based on other subtypes. Prognostic and patient-specific treatment evaluation of ZNF384 fusions in both ALL and MPAL might help to improve risk characterization of patients.

Copy-number variations in adult patients with chronic immune thrombocytopenia.

OBJECTIVES: Immune thrombocytopenia (ITP) is an autoimmune disease with heterogeneous background. FCGR2C mutations were defined in one third of the patients but genetic players have not been fully elucidated yet. Although childhood ITP present as benign, ITP in adulthood is chronic disease with treatment challenges. This study aimed to focus on adult ITP patients using a whole genome genotyping that is valuable approach to identify the responsible genomic regions for the disease. METHODS: Herein 24 adult primary-refractory for ITP patients were evaluated using HumanCytoSNP12BeadChip,Illumina. Forty-six age and sex matched healthy individuals, and ptients awith nonhematological conditions were analyzed as controls. Identified CNV regions were verified by qRTPCR. T-cell receptor beta and delta (TCRB/TCRG) clonality were assessed by heteroduplex analysis in mosaic cases. RESULTS: Several CNV losses and gains were defined (losses:2q,7q,17q,19p, and gains: 1q,2p,3q,4q,7q,10q,12p,13q,14q,15q,17p,20q,21p,22q,Xp). Mosaic changes of different sizes (0.2-17.77Mb) were identified in five patients and three of them showed clonality. CNV regions that were unique to ITP patients were identified for the first time and among these genes, those related to immune regulation, and cellular trafficking were noteworthy. Conclusion: Identified CNV regions harbor several candidate genes, the functions of which might shed light on the pathogenesis of chronic ITP.