Vitamin D status and the immune assessment in 22q11.2 deletion syndrome.

22q11.2 deletion syndrome (22q11.2DS) is characterized by a heterogeneous phenotype, including alterations in phospho-calcium metabolism and immunodeficiency. We analyzed vitamin D status and the immune assessment, focusing on T cell subpopulations and dendritic cells (DCs) in a cohort of 17 pediatric 22q11.2DS patients and 17 age-matched healthy subjects. As antigen-presenting cells, DCs are the main target of vitamin D, promoting a tolerogenic T cell response. Patients were subdivided into three groups according to the parameters of phospho-calcium metabolism and serum levels of 25OHD: normal values, vitamin D deficiency and hypoparathyroidism. Different degrees of T cell deficiency, ranging from normal to partial T cell numbers, were observed in the cohort of patients. The group with vitamin D deficiency showed a significant reduction of naive T cells and a significant increase of central memory T cells compared to controls. In this group the number of circulating DCs was significantly reduced. DC decrease affected both myeloid and plasmacytoid DC subsets (mDCs and pDCs), with the most relevant reduction involving pDCs. A direct correlation between 25OHD levels and recent thymic emigrant (RTE) and DC number was identified. Despite the limited cohort analyzed, our results show that deficiency of the pDC subset in patients with 22q11.2DS may be included among the causative factors of the progressive increase of risk of autoimmune diseases in these patients. As most patients suffer from increased susceptibility to infections and heightened prevalence of autoimmune disorders, we suggest a potential role of vitamin D supplementation in preventing autoimmune or proinflammatory diseases in 22q11.2DS.

Methylenetetrahydrofolate reductase polymorphism (MTHFR C677T) and headache in children: a retrospective study from a tertiary level outpatient service.

BACKGROUND: In adult studies the MTHFR C677T polymorphism has been associated with an increased risk of migraine, but little research has been done in this area in children. METHODS: A retrospective study of children referred with headache to a tertiary level Paediatric Neurology Service between 2008 and 2012. This study included only patients who had been genotyped for the MTHFR C677T polymorphism. An evaluation of homocysteine serum levels was necessary to exclude other types of migraine. CONCLUSION: Compared with the wild-type genotype, the T/T genotype was associated with an increased risk of any type of migraine, though the statistical significance was greatest in migraine with aura. The homocysteine serum levels were significantly higher in migraine with aura compared to migraine without aura. In a pediatric population MTHFR T/T homozygosity influences susceptibility to migraine.

Generalized epilepsy and mild intellectual disability associated with 13q34 deletion: A potential role for SOX1 and ARHGEF7.

Terminal deletions of long arm of chromosome 13 are rare and poorly characterized by cytogenetic studies, making for difficult genotype-phenotype correlations. We report two siblings presenting generalized epilepsy, intellectual disability, and genitourinary tract defects. Array CGH detected a 1.3 Mb deletion at 13q34; it contains two protein-coding genes, SOX1 and ARHGEF7, whose haploinsufficiency can contribute to the epileptic phenotype.

17q12 microduplications: a challenge for clinicians.

In the recent years, some cases of 17q12 deletions and duplications have been reported, but the clinical impact of these imbalances is still to be fully elucidated. In particular, 17q12 duplications elude syndrome classification, since they are associated with a wide phenotypic spectrum, ranging from very mild to quite severe phenotypes. Here, two unrelated patients with the same 1.2 Mb microduplication of 17q12 are reported. Comparing these patients' phenotype with those previously published, it emerges that the more patients reported, the more difficult is finding common characteristics, even in presence of exactly the same genetic anomaly. The role of the genes duplicated in this region and the impact of this chromosomal imbalance are discussed.

45,X maleness: clinical and cytogenetic features in two patients.

45,X maleness is a very rare disorder. We report on 2 new 45,X males aged 9 10/12 and 39 years, respectively. The boy presented for developmental delay, while the man was referred to us because of infertility. Both patients showed short stature (boy -2.29 SDS, man -4.05 SDS) and an unbalanced translocation of Yp, including SRY, onto the long arm of chromosome 10 and short arm of chromosome 14, respectively. The growth pattern of the 2 patients and literature data suggest the presence of a specific growth gene in the pericentrometric region of Yq. In addition, developmental delay in some 45,X males may be related to specific deletion of telomeric autosome regions, but involvement of gene(s) on the Y chromosome may play a role as well. Albeit in the boy inhibin B levels were in the normal range for age, azoospermia was demonstrated in the adult, supporting that infertility is a feature of adult 45,X men with AZFa-c deletion.

Characterization of the phenotype and definition of the deletion in a new patient with ring chromosome 22.

The clinical phenotype of patients with ring chromosome 22 includes mental retardation with severe language impairment, hypotonia, and dysmorphic facial features. In recent years an increasing number of patients with microscopic as well as cryptic terminal deletion involving band 22q13 have been described and their phenotype shows clinical features overlapping with patients with ring chromosome 22. Loss of DNA in the 22q13.3 region may lead to a clinically recognizable syndrome named "22q13.3 deletion syndrome." We report a patient with a ring chromosome 22 who has hypotonia, profound mental retardation, language impairment, dysmorphic features, and behavioral disorders. To check if the critical region responsible for "22q13.3 deletion syndrome" was absent in this ring, a fluorescent in situ hybridization (FISH) analysis using a probe corresponding to the ARSA locus was performed. In our patient, only one ARSA signal could be detected, indicating that the deletion encompassed the critical 22q13.3 region. A more detailed analysis of the deletion extent then was performed using a panel of fluorescent probes located within 22q13. These experiments allowed the identification of the breakpoint between CTA-299D3 and RP5-925J7 probe, located in 22q13.32. Deletion extent could be estimated to be about 2.5 Mb, and this larger deletion may explain the severity of clinical features observed in our patient.

A new strategy for prenatal diagnosis in a sporadic haemophilia B family.

Although the quality of life for haemophiliacs has clearly improved in the last few years, haemophilia still remains a serious disorder justifying prenatal diagnosis (PD) and, if necessary, termination. Because chorionic villus sampling (CVS) is performed in the first trimester of pregnancy, an increasing number of carriers are interested in this test. It has been shown that waiting for the results is particularly distressing for pregnant women, therefore decreasing the diagnostic procedure time can be psychologically helpful. Here we report on PD in a sporadic haemophilia B family based on the direct identification of the pathogenic mutation in a CVS taken at the 12th gestational week. In order to hasten the results, we recovered DNA from a single villus fragment boiled in water and used it directly for PCR reaction. Conformation-sensitive gel electrophoresis (CSGE) was used to detect the mutation in the haemophilia carrier and in the foetus. This approach allowed us to obtain a diagnosis within 24 h of CVS, thus avoiding the long-term psychological effects on the pregnant woman.

Detection of T cell receptor delta gene rearrangements in childhood B and T lineage acute lymphoblastic leukaemia by southern blot and PCR: technical comparison of two methods of analysis.

Molecular analysis of antigen receptor genes (Ig and TCR) has been useful for clonal studies in acute lymphoblastic leukaemia (ALL) patients. Rearrangements of these genes can be used to track the persistence of the leukaemic clone during the therapy. The purpose of our study was to analyse the percentage and the pattern of the rearrangements at the TCR D locus in a series of ALL patients, comparing the results obtained by Southern blot and PCR. Genomic DNA was extracted from mononuclear BM cells of 40 paediatric ALL cases, digested with different restriction enzymes and hybridized to TCRDJ1 probe to study the TCR delta locus. Amplification of the rearranged TCR delta genes was performed by PCR to define the gene segments involved. The junctional region was deduced from the sequence to obtain patient-specific primers. Among the 31 B lineage ALL samples, one or two TCR delta alleles proved to be rearranged in 53% of cases. Two different types of rearrangements were chiefly detected: Vdelta2Ddelta3 and Ddelta2Ddelta3. In T-ALL patients, the predominant rearrangement involved the Vdelta1 and the Jdelta1 gene segments.

Late Epstein-Barr virus infection of a hepatosplenic gamma delta T-cell lymphoma arising in a kidney transplant recipient.

BACKGROUND AND OBJECTIVE: gd T-cell lymphomas are only exceptionally observed in transplanted patients. Aim of this study was the detailed characterization of one such case. DESIGN AND METHODS: The patient developed spontaneous splenic rupture six years after kidney transplantation. The splenic red pulp was infiltrated by medium-sized and large lymphoid cells with two or more nucleoli. At autopsy, similar lymphoid cells infiltrated the hepatic sinusoids. Histologic, immunologic and molecular studies were carried out. RESULTS: By immunohistochemistry, the atypical lymphoid cells were found to express CD3, CD45 and CD43, indicating their T-lineage origin. Approximately 99% of spleen mononuclear cells (MNC) were CD3(+), gammadelta TcR+, CD4-, CD8-, alphabeta TcR-. A clonal gammadelta TcR rearrangement (Vgamma1-Jgamma1.3/2.3-Cgamma2; Vdelta1-Ddelta2-Jdelta1) was detected. The final diagnosis was peripheral T-cell lymphoma, hepato-splenic gammadelta-type. EBV infection of spleen MNC was documented by molecular studies. However, in situ hybridization for EBER-1 (EBV-RNA) showed that only a minority of malignant lymphoid cells (5-7%) were EBV-infected. INTERPRETATION AND CONCLUSIONS: It is concluded that EBV infection was as a late event involving an already transformed gd T-cell clone.

Accumulation of clonally related B lymphocytes in the cerebrospinal fluid of multiple sclerosis patients.

The accumulation of B lymphocyte clones in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and patients with other neurological disorders was investigated using PCR technologies. Oligoclonal B cell accumulations were detected in 10 of 10 MS patients, but only in 3 of 10 of the patients with other neurological disorders. Analyses of the Ig V(D)J sequences on the CSF from MS patients disclosed that VH3 and VH4 genes were extensively mutated compared with germline sequences. Moreover, a substantial proportion of the molecular clones analyzed shared the same third CDR of the H chain variable region gene (HCDR3) and the same VH genes, albeit with different numbers and locations of point mutations, thus indicating an ongoing process of intraclonal diversification. A larger number of clonally related VH sequences could be obtained by using a VH3 gene-specific PCR so that genealogical trees depicting the process of diversification could be drawn. Analyses of the Ig V(D)J from the CSF of a patient with viral meningitis and oligoclonal B cell accumulations revealed that VH3 genes were extensively mutated. However, no intraclonal diversification could be observed even using VH3 gene-specific PCR methodologies. Clone-specific PCR and sequencing was used to detect the V(D)J found in the CSF of one MS patient in the PBL of the same patient. Only 1/3 of the V(D)J sequences investigated could be demonstrated in the PBL, indicating that the V(D)J genes utilized by B cells in the CSF are much less represented in the PBL. Collectively, the data suggest that in MS there is a compartmentalized clonal expansion.

Ig V gene mutation status and CD38 expression as novel prognostic indicators in chronic lymphocytic leukemia.

Cellular immunophenotypic studies were performed on a cohort of randomly selected IgM(+) B-chronic lymphocytic leukemia (B-CLL) cases for which Ig V(H) and V(L) gene sequences were available. The cases were categorized based on V gene mutation status and CD38 expression and analyzed for treatment history and survival. The B-CLL cases could be divided into 2 groups. Those patients with unmutated V genes displayed higher percentages of CD38(+) B-CLL cells (>/=30%) than those with mutated V genes that had lower percentages of CD38(+) cells (<30%). Patients in both the unmutated and the >/=30% CD38(+) groups responded poorly to continuous multiregimen chemotherapy (including fludarabine) and had shorter survival. In contrast, the mutated and the <30% CD38(+) groups required minimal or no chemotherapy and had prolonged survival. These observations were true also for those patients who stratified to the Rai intermediate risk category. In the mutated and the <30% CD38(+) groups, males and females were virtually equally distributed, whereas in the unmutated and the >/=30% CD38(+) groups, a marked male predominance was found. Thus, Ig V gene mutation status and the percentages of CD38(+) B-CLL cells appear to be accurate predictors of clinical outcome in B-CLL patients. These parameters, especially CD38 expression that can be analyzed conveniently in most clinical laboratories, should be valuable adjuncts to the present staging systems for predicting the clinical course in individual B-CLL cases. Future evaluations of new therapeutic strategies and drugs should take into account the different natural histories of patients categorized in these manners.

Chronic lymphocytic leukemia B cells express restricted sets of mutated and unmutated antigen receptors.

To better understand the stage(s) of differentiation reached by B-type chronic lymphocytic leukemia (B-CLL) cells and to gain insight into the potential role of antigenic stimulation in the development and diversification of these cells, we analyzed the rearranged VH genes expressed by 83 B-CLL cells (64 IgM+ and 19 non-IgM+). Our results confirm and extend the observations of a bias in the use of certain VH, D, and JH genes among B-CLL cells. In addition, they indicate that the VH genes of approximately 50% of the IgM+ B-CLL cells and approximately 75% of the non-IgM+ B-CLL cells can exhibit somatic mutations. The presence of mutation varies according to the VH family expressed by the B-CLL cell (VH3 expressers displaying more mutation than VH1 and VH4 expressers). In addition, the extent of mutation can be sizeable with approximately 32% of the IgM+ cases and approximately 68% of the non-IgM+ cases differing by > 5% from the most similar germline gene. Approximately 20% of the mutated VH genes display replacement mutations in a pattern consistent with antigen selection. However, CDR3 characteristics (D and JH gene use and association and HCDR3 length, composition, and charge) suggest that selection for distinct B cell receptors (BCR) occurs in many more B-CLL cells. Based on these data, we suggest three prototypic BCR, representing the VH genes most frequently encountered in our study. These data suggest that many B-CLL cells have been previously stimulated, placing them in the "experienced" or "memory" CD5(+) B cell subset.

Rapid detection of gammaT cell receptor gene rearrangements in acute lymphoblastic leukemia by electrophoresis and silver staining: implications for detection of minimal residual disease.

Minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL) was studied using polymerase chain reaction (PCR). GammaT cell receptor (TCRG) genes are ideal targets for PCR-based detection of MRD due to their molecular characteristics. Polyacrylamide gel electrophoresis (PAGE) analysis of PCR products followed by silver staining was performed for 72 children with ALL at the onset of disease. Silver staining is an effective technique to detect gene rearrangements without the use of ethidium bromide. Moreover, this method may show heteroduplex bands of a clonal nature when both TCRG alleles are rearranged. PCR products subjected to a rapid staining protocol were recovered from the gel, reamplified by a second PCR and directly sequenced. After sequencing, we identified the junctional region and obtained patient-specific probes. In more than half of the patients we detected TCRG rearrangements that were used as molecular markers for residual disease.

Inversion mutation as a major cause of severe hemophilia A in Italian patients.

We investigated the presence of a recombinant event between the F8A gene located in intron 22 of the factor VIII gene and the two additional copies of F8A lying 500 Kb upstream of FVIII in severe hemophilic patients. The genomic DNA of 146 unrelated Italian patients with severe hemophilia A (HA) was hybridized with an F8A gene probe to detect the abnormal band patterns. A recombinant event was found in 71/146 patients, confirming the high incidence of this mutation in the Italian hemophilic population also. We conclude that the high frequency of the mutation in HA subjects allows us to make a direct and safe diagnosis in about 50% of our families without resorting to RFLP analysis.