Early-onset indicators of a hypercoagulable state and clinical complications in a cohort of children with sickle cell trait.

Adults with sickle cell trait (SCT) have a procoagulant state with increased risk of thromboembolism, but limited data are available for children. We compared the coagulation profile of children with SCT, different sickle cell disease (SCD) genotypes, and healthy controls. Compared to controls and similarly to HbSC patients, 41 SCT children (mean age 6.85 years; 20 males; 88% Africans) had a characteristic procoagulant profile: higher levels of factor VIII, von Willebrand factor (VWF) Ag and CBA, D-dimer; lower levels of ADAMTS 13 activity, ADAMTS13 activity: VWFAg, plasminogen activator inhibitor, tissue plasminogen activator. Moreover, 13/41 had clinical complications of SCD, five requiring hospitalization.

CK2ß Regulates Hematopoietic Stem Cell Biology and Erythropoiesis.

The Ser-Thr kinase CK2 plays important roles in sustaining cell survival and resistance to stress and these functions are exploited by different types of blood tumors. Yet, the physiological involvement of CK2 in normal blood cell development is poorly known. Here, we discovered that the ß regulatory subunit of CK2 is critical for normal hematopoiesis in the mouse. Fetal livers of conditional CK2ß knockout embryos showed increased numbers of hematopoietic stem cells associated to a higher proliferation rate compared to control animals. Both hematopoietic stem and progenitor cells (HSPCs) displayed alterations in the expression of transcription factors involved in cell quiescence, self-renewal, and lineage commitment. HSPCs lacking CK2ß were functionally impaired in supporting both in vitro and in vivo hematopoiesis as demonstrated by transplantation assays. Furthermore, KO mice developed anemia due to a reduced number of mature erythroid cells. This compartment was characterized by dysplasia, proliferative defects at early precursor stage, and apoptosis at late-stage erythroblasts. Erythroid cells exhibited a marked compromise of signaling cascades downstream of the cKit and erythropoietin receptor, with a defective activation of ERK/JNK, JAK/STAT5, and PI3K/AKT pathways and perturbations of several transcriptional programs as demonstrated by RNA-Seq analysis. Moreover, we unraveled an unforeseen molecular mechanism whereby CK2 sustains GATA1 stability and transcriptional proficiency. Thus, our work demonstrates new and crucial functions of CK2 in HSPC biology and in erythropoiesis.

Hematological characteristics and hepatobiliary complications of hereditary spherocytosis in a tertiary care pediatric center: optimizing diagnosis and care through local and international networks.

Background: Hereditary Spherocytosis (HS) is a rare, congenital red blood cell disorder presenting with variable clinical manifestations ranging from mild hemolytic anemia to severe anemia with hypersplenism and hepatobiliary complications. Methods: The objectives of the study were to evaluate the diagnostic pathway of HS, the presence and management of hepatobiliary complications in pediatric patients with HS followed in a tertiary care center. The demographic, clinical, hematological information were retrieved from medical records of patients having at least 1 hematology visit between 2010 and 2020. Results: Forty-two patients were enrolled, 23 M. Mean age at onset of symptoms was 2.8 years, at diagnosis was 3.5 years. Anemia was the first manifestation in 73%; suspect of HS arose for all patients in first or second level outpatient clinics. Only 64% of patients performed two confirmation tests in the reference center. 28/42 had familiarity for HS; of the 13/42 who did not, only 47% performed further analysis. Sixteen patients developed gallbladder stones (40%), visible at the first ultrasound (5.6 years). Hemolytic crises and parvovirus infections were more frequent in patients with stones (53.6% vs. 26.1% and 63.6% vs. 28.6%, respectively). 10/16 (62.5%) underwent elective cholecystectomy: 8 had concomitant splenectomy. Conclusions: our study highlights the need to optimize the diagnostic pathway in networks of care involving general and specialized centers in order to reduce time to diagnosis and ensure that all patients receive confirmatory tests. A high frequency of hepatobiliary complications since young age was observed suggesting that screening with ultrasound should begin earlier.

Point-of-care testing allows successful simultaneous screening of sickle cell disease, HIV, and tuberculosis for households in rural Guinea-Bissau, West Africa.

Diagnosis of noncommunicable genetic diseases like sickle cell disease (SCD) and communicable diseases such as human immunodeficiency virus (HIV) or tuberculosis (TB) is often difficult in rural areas of Africa due to the lack of infrastructures, trained staff, or capacity to involve families living in remote areas. The availability of point-of-care (POC) tests for the above diseases offers the opportunity to build joint programs to tackle all conditions. We report successful simultaneous screening of SCD, HIV, and TB utilizing POC tests in 898 subjects in Fanhe, in rural Guinea-Bissau. Adherence was 100% and all diagnosed subjects were enrolled in care programs.

Distribution of HbS Allele and Haplotypes in a Multi-Ethnic Population of Guinea Bissau, West Africa: Implications for Public Health Screening.

Background: Sickle Cell Disease (SCD) is an inherited condition that is widespread globally and especially in malaria-endemic West African countries. Limited epidemiological data on SCD are available for Guinea Bissau, where newborn screening is not yet implemented, routine diagnosis is not available, and care is case directed. Methods: Dried blood spots were collected from children accessing two hospitals managed by Italian Non-Governmental Organizations in the capital city of Bissau and sent to Padova for Hemoglobin (Hb) quantification through HPLC and molecular analysis. Beta globin gene analysis was performed in all; and Hb haplotype of the HbSS and HbSA patients was performed in South Africa. One hundred samples belonging to the most frequent ethnic groups were randomly selected for detection of G6PD mutations. Results: Samples from 848 consecutive children (498 males and 350 females, mean age 6.8 years) accessing the two hospitals were analyzed: 6.95% AS (4.42% allelic frequency), 0.94% SS, and 0.23% AC. 376G G6PD allelic frequency was 24%; 14.8% in AS individuals. The Senegal haplotype was the most prevalent (31%), and the proposition of chromosomes with the atypical haplotype was surprisingly high (56%). Conclusion: Our study demonstrates a significant frequency of the HbS allele in the population of Guinea Bissau supporting the implementation of screening strategies. The differences among ethnic groups can help guide targeted interventions for SCD awareness campaigns and determine priority areas for public health interventions. The pilot analysis on haplotypes reveals a large proportion of the atypical haplotype, which may be indicative of a genetically heterogeneous population.

Neonatal Manifestations of Chronic Granulomatous Disease: MAS/HLH and Necrotizing Pneumonia as Unusual Phenotypes and Review of the Literature.

Chronic granulomatous disease (CGD) is a rare inborn error of immunity (IEI), characterized by a deficient phagocyte killing due to the inability of NADPH oxidase to produce reactive oxygen species in the phagosome. Patients with CGD suffer from severe and recurrent infections and chronic inflammatory disorders. Onset of CGD has been rarely reported in neonates and only as single case reports or small case series. We report here the cases of three newborns from two different kindreds, presenting with novel infectious and inflammatory phenotypes associated with CGD. A girl with CYBA deficiency presented with necrotizing pneumonia, requiring a prolonged antibiotic treatment and resulting in fibrotic pulmonary changes. From the second kindred, the first of two brothers developed a fatal Burkholderia multivorans sepsis and died at 24 days of life. His younger brother had a diagnosis of CYBB deficiency and presented with Macrophage Activation Syndrome/Hemophagocytic Lympho-Histiocytosis (MAS/HLH) without any infection, that could be controlled with steroids. We further report the findings of a review of the literature and show that the spectrum of microorganisms causing infections in neonates with CGD is similar to that of older patients, but the clinical manifestations are more diverse, especially those related to the inflammatory syndromes. Our findings extend the spectrum of the clinical presentation of CGD to include unusual neonatal phenotypes. The recognition of the very early, potentially life-threatening manifestations of CGD is crucial for a prompt diagnosis, improvement of survival and reduction of the risk of long-term sequelae.

Neonatal-Onset Familial Mediterranean Fever in an Infant with Human Parainfluenza Virus-4 Infection.

Unusual, severe infections or inflammatory episodes in newborns and infants are largely unexplained and often attributed to immature immune responses. Inborn errors of immunity (IEI) are increasingly recognized as the etiology of life-threatening inflammatory and infectious diseases in infancy. We describe a patient with a unique neonatal-onset Familial Mediterranean Fever (FMF) due to compound heterozygous variants in MEFV, presenting as pleuritis following human parainfluenza virus-4 infection. Diagnostic challenges of FMF in infancy include the interpretation of the attacks as infectious episodes. Newborns and infants with acute, recurrent, or chronic, unusually severe infectious or inflammatory conditions should be screened for IEI, including both disorders with defective immunological responses and autoinflammatory disorders.

Results of a multicenter universal newborn screening program for sickle cell disease in Italy: A call to action.

BACKGROUND: Sickle cell disease (SCD) is a chronic multisystem disorder requiring comprehensive care that includes newborn screening (NBS) as the first step of care. Italy still lacks a national SCD NBS program and policy on blood disorders. Pilot single-center screening programs and a regional targeted screening have been implemented so far, but more evidence is needed in order to impact health policies. POPULATION AND METHODS: NBS was offered to parents of newborns in gynecology clinics in Padova and Monza, tertiary care university hospitals in northern Italy. High-performance liquid chromatography (HPLC) was performed as the first test on samples collected on Guthrie cards. Molecular analysis of the beta-globin gene was performed on positive samples. RESULTS: A total of 5466 newborns were enrolled; for 5439, informed consents were obtained. A similar family origin was seen in the two centers (65% Italians, 9% mixed couples, 26% immigrants). Compared with SCD NBS programs in the United States and Europe, our results show a similar incidence of SCD patients and carriers. All SCD patients had a Sub-Saharan family background; HbS carriers were 15% Caucasians (Italian, Albanians) and 10% from other areas (North Africa-India-South America); carriers of other hemoglobin variants were mainly (47%) from other areas. CONCLUSIONS: Our results demonstrate the feasibility of a multicentric NBS program for SCD, give information on HbS epidemiology in two Northern Italian Areas, and support previous European recommendation for a universal NBS program for SCD in Italy: a high incidence of patients and carriers has been detected, with a high percentage of Caucasian carriers, impossible to identify in a targeted NBS.

Evaluation of Technical Issues in a Pilot Multicenter Newborn Screening Program for Sickle Cell Disease.

A multicenter pilot program for universal newborn screening of Sickle cell disease (SCD) was conducted in two centres of Northern Italy (Padova and Monza). High Performance Liquid Chromatography (HPLC) was performed as the first test on samples collected on Guthrie cards and molecular analysis of the ß-globin gene (HBB) was the confirmatory test performed on the HPLC-positive or indeterminate samples. 5466 samples of newborns were evaluated. Of these, 5439/5466 were submitted to HPLC analysis and the molecular analysis always confirmed in all the alteration detected in HPLC (62/5439 newborns); 4/5439 (0.07%) were SCD affected, 37/5439 (0.68%) were HbAS carriers and 21/5439 (0.40%) showed other hemoglobinopathies. Stored dried blood spots were adequate for HPLC and ß-globin gene molecular analysis. Samples were suitable for analysis until sixteen months old. A cut-off of A1 percentage, in order to avoid false negative or unnecessary confirmation tests, was identified. Our experience showed that several technical issues need to be addressed and resolved while developing a multicenter NBS program for SCD in a country where there is no national neonatal screening (NBS) program for SCD and NBS programs occur on a regional basis.

Identification and in silico analysis of novel von Hippel-Lindau (VHL) gene variants from a large population.

Mutational inactivation of the VHL gene is the cause of von Hippel-Lindau (VHL) disease, an autosomal dominant hereditary cancer syndrome predisposing to haemangioblastomas, pheochromocytomas and clear-cell renal carcinomas. The gene product (pVHL) functions as an adapter in cellular processes including cell growth and apoptosis. VHL mutation analysis was carried out in 426 unrelated subjects with phenotypes ranging from VHL syndrome, to isolated VHL-related tumours that could represent the first manifestation of the disease. A total of 111 individuals were found to carry alterations, with large deletions representing 40% of the variants. Eighteen of the 95 detected variants were novel, seemingly disease-causing mutations; their pathogenic role has been evaluated in silico for effects on protein folding and interactions. Putative regions of interaction between pVHL and proteins involved in common pathways have been identified, assessing possible implications for the presence of mutations in these regions. All new variants predicted to truncate or cause complete pVHL loss of structure were associated with phenotypes consistent with VHL type 1. Seven of the new amino acid substitutions are disease-causing mutations, one is a neutral variant, whereas the results for two remain ambiguous. Our combined molecular and in silico approach for the evaluation of putative disease-causing mutations contributes to the interpretation of the potential pathogenicity of these novel variants.

Familial nonsyndromic pheochromocytoma.

Judging from recent data, heritable forms account for 30-40% of pheochromocytomas. The molecular basis for the familial pheochromocytoma has been largely elucidated and the role of germline mutation of the VHL, RET, SDHB, and SDHD genes has been established. However, on genotyping a group of 172 sporadic or familial pheochromocytomas, we characterized four unrelated probands with familial pheochromocytomas without any sequence variants of RET (exons 8, 10, 11, 13, 14, 15, and 16) or the entire coding sequence of VHL, SDHB, SDHC, SDHD, and EGLN3 (exon-intron boundaries included). The proband of family 1 is a man who had a bilateral pheochromocytoma at the age of 32 and a local recurrence at the age of 48 years. His brother died of malignant pheochromocytoma and his nephew died suddenly of an undiagnosed pheochromocytoma. The proband of family 2 is a female who had a 5-cm benign adrenal pheochromocytoma at the age of 34 years, while her cousin (maternal branch) had a monolateral pheochromocytoma at the age of 42 years. No other tumors had been reported in either family. The proband of family 3 is a female who had a bilateral pheochromocytoma at the age of 66 years. Her sister had a bilateral pheochromocytoma and breast cancer at the age of 54 years. Several other tumors were recorded in this family, including laryngeal cancer, leukemia, and a case of medullary thyroid carcinoma (MTC) in one brother. MTC was naturally ruled out in the proband and her sister. In family 4, the proband was a female who had a bilateral pheochromocytoma at the age of 46 years and a local recurrence a few years later, with liver metastases from the pheochromocytoma. Her brother had a monolateral benign pheochromocytoma. The proband also had a melanoma and bilateral renal cysts. This case revealed a VHL sequence variant IVS2+43 A>G, which was also found in one other unrelated sporadic pheochromocytoma. VHL mRNA integrity is currently being evaluated. The proband had no cerebellar or spinal NMR findings or retinal alterations. In family 5, the proband was a female who had a right adrenal pheochromocytoma at the age of 50 years and a breast cancer at 49 years of age. Her mother had had a right adrenal pheochromocytoma at 61 years of age. Although other molecular mechanisms, such as particular variants in untranslated regions or partial gene deletions, cannot be ruled out, we think finding families with nonsyndromic pheochromocytoma without any RET, VHL, SDHB, SDHC, SDHD, or EGLN3 mutation may argue in favor of the presence of other pheochromocytoma susceptibility genes.

Molecular analysis of two uncharacterized sequence variants of the VHL gene.

Mutations in the VHL gene cause von Hippel-Lindau disease, a cancer predisposing syndrome characterized by a variety of benign and malignant neoplasms. We report the molecular characterization of two sequence variants of the VHL gene: a synonymous substitution c.462 A>C in exon 2 and a duplication of 11 bp in the promoter region (c.-65_-55dup11). The first variant is a pathogenic mutation because, although it does not change the sense of the affected codon, it causes skipping of exon 2 in the affected allele by altering the splicing consensus site at the 3' end of exon 2. The 11 bp duplication represents a nonpathogenic variant. In fact, although it affects a critical region of the VHL promoter, it was found in healthy controls, and we show that carrier individuals express both VHL alleles at equimolar levels. Our data underline the importance of careful evaluation of the potential pathogenicity of sequence variants that may not belong to the obvious disease-causing mutation categories, or that affect relevant regulatory regions. mRNA analysis will be required to ultimately resolve this issue.

Molecular characterization of large deletions in the von Hippel-Lindau (VHL) gene by quantitative real-time PCR: the hypothesis of an alu-mediated mechanism underlying VHL gene rearrangements.

INTRODUCTION: Mutations of the von Hippel-Lindau (VHL) gene are responsible for VHL disease. This is a familial autosomal-dominant syndrome, predisposing to the development of benign and malignant tumors, including CNS and retinal hemangioblastomas, pheochromocytomas, and clear cell renal carcinomas. At least 30% of the disease-causing mutations in the VHL gene involve large alterations. Identification of these mutations is not possible using PCR-based mutational scanning methods. Quantitative Southern blot analysis has been traditionally employed for the detection of complete or partial deletions and more complex rearrangements of the gene. METHODS: An alternative quantitative method was developed using a combination of quantitative Southern blot analysis and real-time PCR. With this approach, we studied 24 large VHL gene alterations to determine the exact nature of the mutations and to possibly characterize the boundaries of the deleted regions. RESULTS: This combined molecular approach showed that all the VHL alterations studied were due to deletions, from which the position in the gene could be more precisely mapped. One of the samples that was completely characterized was found to carry an intragenic 2.2kb deletion with both 5' and 3' breakpoints located within Alu-repeat sequences. CONCLUSION: This is the first report on the molecular analysis of large VHL alterations. The results of our study and the complete characterization of a large deletion lead to the hypothesis that an Alu-mediated mechanism may be responsible for the common occurrence of large alterations in the VHL gene.

Low frequency of VHL gene mutations in young individuals with polycythemia and high serum erythropoietin.

In one out of six young individuals with polycythemia and high erythropoietin levels we found a heterozygous VHL gene mutation (430G->A;Gly144Arg). The man's unaffected mother and sister carry the same mutation. No other VHL genomic or expression alterations were found. In one other patient different genetic conditions were found.

Connexin 26 preverbal hearing impairment: mutation prevalence and heterozygosity in a selected population.

The objective of this investigation was to determine the prevalence of Cx26 mutations in familial and sporadic cases of non-syndromic preverbal hearing impairment (HI). Molecular analysis of the Connexin 26 (Cx26/GJB2) gene was performed in 271 non-consanguineous individuals from the north of Italy, enrolled in the study because of the presence of non-syndromic preverbal sensorineural HI. One hundred and forty-six subjects (group 1) were referred from different ENT, paediatric and clinical genetic services, while 125 individuals (group 2) underwent Cx26 analysis based on precise anamnestic and clinical criteria for non-syndromic HI and low risk of acquired deficit. All of the cases were also classified as familial or sporadic due to the presence or absence of other documented childhood HI in the family. Of the total 271 individuals, 36.9% were positive for Cx26 mutations: 37 belonged to group 1 and 63 to group 2, which delineates a statistically significant difference between the two groups. The difference is mainly attributable to sporadically occurring cases. No significant differences between group 1 and group 2 were found regarding the prevalence of the common 35delG variant and the number of unidentified putative Cx26 alleles, although these latter were shown to be higher in sporadically occurring cases of the unselected group 1. The difference observed in Cx26 prevalence can be explained by the clinical selection of group 2, which ensures minimum risk of including cases of acquired HI. In particular, in cases of sporadically occurring HI, the use of a defined protocol increases the chances of a positive molecular result, improving genetic counselling and the possibility of establishing better genotype-phenotype correlation. Our data raise questions about the possible interpretation of Cx26 heterozygosity in a selected population of hearing-impaired individuals.