Diagnostic potential of hepcidin testing in pediatrics.

OBJECTIVES: Hepcidin, a peptide hormone released by hepatocytes into circulation is the main regulator of dietary iron absorption and cellular iron release. Although commercial tests are available, assay harmonization for hepcidin has not been yet reached, making reference intervals and consequent clinical decisions still elusive for each assay and specific population. The aim of this study is to set up hepcidin measurement in pediatric age and to investigate its potential usefulness in the diagnosis and management of iron disorders in children. METHODS: Serum hepcidin was measured by using an automated commercial immunoassay. Reference values were obtained from 86 healthy children. Hepcidin was then evaluated in 52 children with diseases where this hormone was expected to be differently regulated. RESULTS: Hepcidin values were 43.6 ng/mL median; 32-52.7 1-3 q: in males and 36.4 ng/mL median; 28.5-45.7 1-3 q: in females (P = 0.039). Hepcidin was significantly higher in postpubertal normal females than in normal males. Hepcidin resulted up-regulated in anemia of chronic disease of children affected by systemic Juvenile Idiopathic Arthritis and decreased after treatment with anakinra, an anti-interleukin-1 receptor antagonist. In iron deficiency anemia patients on oral iron supplementation and in ß-thalassemia subjects, hepcidin levels were similar to those found in healthy subjects. CONCLUSIONS: This study sets up reference values for pediatric population and shows that in normal controls serum hepcidin react differently to puberty in females vs. males. In addition, it suggests that serum hepcidin may discriminate microcytic inflammatory anemia of Juvenile Idiopathic Arthritis from iron deficiency anemia. Overall these findings may represent a helpful tool for future studies tailored to understand the role of hepcidin in management of iron disorders in children.

Pediatric SARS-CoV-2-Related Diplopia and Mesencephalic Abnormalities.

Objective: This case report describes a patient with mesencephalic MRI signal abnormality and diplopia, possibly associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods: We describe a boy with binocular diplopia and nystagmus. The pattern of serology positivity and negative direct research of SARS-CoV-2 RNA in our patient allowed us to consider novel coronavirus as the trigger of possible immune-mediated phenomena against the central nervous system. Results: During hospitalization, blood tests revealed a recent SARS-CoV-2 infection. MRI revealed hyperintensity of the mesencephalic tegmentum and periaqueductal region, consistent with an inflammatory lesion of the midbrain tegmentum. Viral and bacterial molecular screening on cerebrospinal fluid and isoelectrofocusing analysis, anti-myelin oligodendrocyte glycoprotein, anti-aquaporine-4, and anti-N-methyl-d-aspartate antibodies were negative. The patient was treated with steroids and immunoglobulin therapy with complete remission of neurologic symptoms. Discussion: This report expands the spectrum of pediatric COVID-19-associated neurologic symptoms and highlights a possible isolated neurologic COVID-19-related symptom.

MicroRNA-125b-1 and BLID upregulation resulting from a novel IGH translocation in childhood B-Cell precursor acute lymphoblastic leukemia.

Chromosomal translocations involving the immunoglobulin heavy chain (IGH) locus are common abnormalities in mature B-cell neoplasms. Recent findings have also revealed their significant role in B-cell precursor acute lymphoblastic leukemia. As a rule, IGH translocations generate transcriptional activation of the oncogene localized in the proximity of the breakpoint. In this study, we describe a pediatric case of B-cell precursor acute lymphoblastic leukemia showing microRNA-125b-1 (MIR125B1) and BLID gene overexpression, resulting from a novel t(11;14)(q24.1;q32) translocation involving IGH. This is the first report describing the upregulation of a microRNA due to its juxtaposition to protein-coding gene regulatory elements and the overexpression of two neighboring genes as a consequence of transcriptional enhancers localized in the vicinity of the IGH gene.

Antibodies against Receptor Binding Domain of SARS-CoV-2 spike protein induced by BNT162b2 vaccine: results from a pragmatic, real-life study.

BACKGROUND: As part of the fight against SARS CoV2 infection, vaccination program for health workers at Giannina Gaslini pediatric hospital (IGG) in Genoa, Italy, started on December 2020. We evaluated the anti-Spike protein response in healthcare workers after a complete vaccination scheme of 2 doses spaced by 3 weeks. METHODS: Immunoglobulin class G (IgG) against SARS-CoV-2 spike RBD were detected by means of a chemiluminescence immunoassay for quantitative IgG antibodies using Maglumi SARS-CoV-2-S-RBD IgG kit during the 3rd week after vaccination completion. RESULTS: IgG anti SARS-CoV-2 spike protein were detected in 99.88% of 1765 healthcare workers 3 weeks after 2nd dose of BNT162b2. Higher median IgG values were observed in younger subjects (807 UA/mL in under 30 vs 429 UA/mL in over 60; p < 0.001) and those with previous COVID-19 (1284 vs 574 UA/mL; p < 0.001). CONCLUSION: BNT162b2 is effective in inducing anti SARS-CoV-2 antibodies even in real-life setting. The higher antibody title observed in workers with a previous documented SARS CoV2 infection confirms the possibility to carry out only one dose of BNT162b2 in a context of vaccines shortage.

Inversion (11)(p15q22) with NUP98-DDX10 fusion gene in pediatric acute myeloid leukemia.

The inv(11)(p15q22), a rare but recurrent chromosome abnormality that creates a NUP98-DDX10 fusion gene, is associated with de novo or secondary myeloid malignancies. We report a case of acute monocytic leukemia presenting this rearrangement, studied using fluorescence in situ hybridization (FISH) and reverse transcriptase-PCR (RT-PCR). We also review the cases of inv(11) associated with NUP98-DDX10 reported in the literature.

HCMOGT-1 is a novel fusion partner to PDGFRB in juvenile myelomonocytic leukemia with t(5;17)(q33;p11.2).

PDGFRB, a transmembrane tyrosine kinase receptor for platelet-derived growth factor, is constitutively activated by gene fusion with different partners in myeloproliferative/myelodysplastic disorders with peculiar clinical characteristics. Six alternative partner genes have been described thus far. In this study, we report the molecular cloning of a novel translocation t(5;17)(q33;p11.2) in a case of juvenile myelomonocytic leukemia. The novel partner gene was identified as HCMOGT-1 using 5'-rapid amplification of cDNA ends; fluorescence in situ hybridization and reverse transcriptase-PCR analyses confirmed that the translocation resulted in PDGFRB/HCMOGT-1 fusion. We show that the breakpoint of PDGFRB occurred at the same site of all previously reported PDGFRB translocations.

Familial nonrandom inactivation linked to the X inactivation centre in heterozygotes manifesting haemophilia A.

A basic tenet of the Lyon hypothesis is that X inactivation occurs randomly with respect to parental origin of the X chromosome. Yet, nonrandom patterns of X inactivation are common - often ascertained in women who manifest recessive X-linked disorders despite being heterozygous for the mutation. Usually, the cause of skewing is cell selection disfavouring one of the cell lineages created by random X inactivation. We have identified a three generation kindred, with three females who have haemophilia A because of extreme skewing of X inactivation. Although they have both normal and mutant factor VIII (FVIII) alleles, only the mutant one is transcribed; and, they share an XIST allele that is never transcribed. The skewing in this case seems to result from an abnormality in the initial choice process, which prevents the chromosome bearing the mutant FVIII allele from being an inactive X.

t(9;11)(p22;p15) with NUP98-LEDGF fusion gene in pediatric acute myeloid leukemia.

The rare t(9;11)(p22;p15) translocation is associated with adult acute myeloid leukemia (AML) with immature forms. We report a novel fusion of the NUP98 and LEDGF genes in a pediatric AML with intermediate characteristics between M2-M3 French-American-British (FAB) subtypes exhibiting the same chromosomal rearrangement. Fluorescence in situ hybridization (FISH) and reverse transcriptase-PCR (RT-PCR) studies identified the chimeric transcript product of in-frame fusion of NUP98 exon 8 to LEDGF exon 4.

Exon skipping partially restores factor VIII coagulant activity in patients with mild hemophilia A with exon 13 duplication.

Ectopic mRNA was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) in patients with duplication of F8 gene exon 13, a mutation which has been demonstrated to be a cause of mild hemophilia A in 32% of Northern Italian subjects. Two different transcripts originate from mutated genomic DNA, due to alternative splice processes. The larger-sized transcript contains both duplicated exons 13, the smaller one contains only one exon 13. The residual FVIII:C activity which accounts for the mild hemophilia A phenotype derives from the latter transcript.

Duplication of exon 13 causes one third of the cases of mild hemophilia A in northern Italy.

A rearrangement of exon 13 in the factor VIII gene has been identified as the causative mutation in 32% of Northern Italian patients with mild hemophilia A. We have demonstrated that all share a common haplotype, thus suggesting that the mutation likely occurred in a single ancestor. To date, no predominant mutation has been identified in mild hemophilia A, therefore it would be extremely useful to carry out more extensive studies to ascertain whether the mutation is confined to northern Italy.

Unusual presentation of haemophilia in two paediatric patients.

Haemophilia A is a rare X-linked recessive bleeding disorder caused by deficiency or functional defects in coagulation factor VIII (FVIII). Here, we report two cases of challenging diagnosis of haemophilia A because of unusual presentation. The first case is a 10-month-old female, admitted to our hospital because a neck mass appeared within the previous 24 h, who had a past medical history consistent with recurrent spontaneous haematomas but no family history of bleeding disorders. Despite several radiological evaluations, only the histology of the mass defined the presence of a haematoma. Chromosomal analysis revealed a normal female karyotype and a de-novo mutation into the FVIII intron 22 associated with a skewed X chromosome inactivation. The second case is a male neonate with a history of seizures who underwent brain MRI that showed a suspicious vascular malformation on the quadrigeminal cistern, causing cerebellum compression and hydrocephalus. The clinical conditions of the child progressively worsened and blood tests revealed a severe deficit of FVIII levels. The radiological images were re-evaluated; vascular anomalies were excluded and the diagnosis of haematoma was made. Family history was negative for coagulation disorders. Molecular studies revealed a rearrangement of the FVIII gene involving intron 22. The haemophilia A diagnosis can be challenging. Lack of family history, difficulties in detecting haematomas by imaging techniques, female sex and neonatal age represent misleading factors that can delay the diagnosis.

Small FVIII gene rearrangements in 18 hemophilia A patients: five novel mutations.

Hemophilia A (HA) is a disorder caused by mutations of the FVIII gene, which is located on the tip of the long arm of the X chromosome. In a cohort of 18 unrelated Italian patients affected with HA of varying severity, we performed mutational screening of the gene by denaturing high-performance liquid chromatography (DHPLC) and direct sequencing of abnormal peaks. We identified five novel mutations and 9 previously reported DNA alterations. Two of the 9 previously reported alterations were each common to 3 unrelated patients. Six different mutations were characterized as missense alterations, while 8 were non-missense mutations. Among the new gene alterations, one created a stop codon, one consisted of an out-of frame deletion, and one was a splice-site mutation. The last two were missense alterations. In an attempt to better understand the causative effect of the mutations and the clinical variability of the patients, we investigated the consequences of each missense mutation and visualized the effect of the amino acid change on structural FVIII models.

Mutation analysis impact on the genetic counseling of sporadic hemophilia B families.

Previous studies have shown that hemophilia B (HB) is the result of several different mutations, mostly single nucleotide substitutions, in the factor IX (FIX) gene. In order to evaluate the impact of mutation analysis on genetic counseling in sporadic and uninformative HB familial pedigrees, we re-analyzed by the conformation sensitive gel electrophoresis (CSGE) technique 14 patients, previously studied by restriction fragment length polymorphisms (RFLPs). A single mutation was present within the FIX gene of each patient: 12 mutations were single base substitutions, 1 was a base insertion, and 1 was a four nucleotide deletion; 4/12 mutations have not been described so far. By identifying the detrimental mutations in affected males, carrier status was correctly diagnosed in all the women we studied; 3/12 de novo events were found in maternal meioses with a 25% mutation rate. Identification of the genetic defect was also successfully applied to three prenatal diagnoses.

Analysis of 18 novel mutations in the factor VIII gene.

We describe 18 novel mutations, unreported in the Haemophilia A mutation Databases, that have been identified in a cohort of unrelated, Italian patients affected with haemophilia A (HA). Screening of the factor VIII gene (FVIII) was performed using denaturing high-performance liquid chromatography (DHPLC) and direct sequencing. Eight mutations were characterized as non-missense alterations, and the remaining 10 were missense mutations. Heterozygosity for the identified mutations was observed in the female relatives of patients belonging to eight families with sporadic cases. In an attempt to understand better the causative effect of the mutations and the clinical variability of the patients, missense mutation consequences were investigated for: (1) the nature of the new amino acid; (2) the location of the substituted amino acid within crystallographic and theoretical models; and (3) the degree of conservation of the native residue in factor VIII (FVIII) protein and FVIII-related protein family aligned sequences. These research tools have provided evidence that the mutations we describe involve residues that were conserved, at least in FVIII proteins, in all the species we compared.