Nijmegen breakage syndrome: 25-year experience of diagnosis and treatment in Ukraine.

Introduction: Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder, characterized by microcephaly, immunodeficiency, and impaired DNA repair. NBS is most prevalent among Slavic populations, including Ukraine. Our study aimed to comprehensively assess the prevalence, diagnosis, clinical data, immunological parameters, and treatment of NBS patients in Ukraine. Methods: We conducted a retrospective review that included 84 NBS patients from different regions of Ukraine who were diagnosed in 1999-2023. Data from the Ukrainian Registry of NBS and information from treating physicians, obtained using a developed questionnaire, were utilized for analysis. Results: Among 84 NBS patients, 55 (65.5%) were alive, 25 (29.8%) deceased, and 4 were lost to follow-up. The median age of patients was 11 years, ranging from 1 to 34 years. Most patients originate from western regions of Ukraine (57.8%), although in recent years, there has been an increase in diagnoses from central and southeastern regions, expanding our knowledge of NBS prevalence. The number of diagnosed patients per year averaged 3.4 and increased from 2.7 to 4.8 in recent years. The median age of NBS diagnosis was 4.0 years (range 0.1-16) in 1999-2007 and decreased to 2.7 in the past 6 years. Delayed physical development was observed in the majority of children up to the age of ten years. All children experienced infections, and 41.3% of them had recurrent infections. Severe infections were the cause of death in 12%. The second most common clinical manifestation of NBS was malignancies (37.5%), with the prevalence of lymphomas (63.3%). Malignancies have been the most common cause of death in NBS patients (72% of cases). Decreased levels of CD4+ and CD19+ were observed in 89.6%, followed by a reduction of CD3+ (81.8%) and CD8+ (62.5%). The level of NK cells was elevated at 62.5%. IgG concentration was decreased in 72.9%, and IgA - in 56.3%. Immunoglobulin replacement therapy was administered to 58.7% of patients. Regular immunoglobulin replacement therapy has helped reduce the frequency and severity of severe respiratory tract infections. Conclusion: Improvements in diagnosis, including prenatal screening, newborn screening, monitoring, and expanding treatment options, will lead to better outcomes for NBS patients.

A rare case of primary gastric Hodgkin lymphoma in an adolescent with Nijmegen breakage syndrome.

BACKGROUND: Nijmegen Breakage Syndrome (NBS) is a rare autosomal recessive DNA repair disorder that increases risk of hematological malignancy. Primary gastric malignancies are exceedingly rare in pediatric patients and not typically high on the differential of abdominal pain. CASE PRESENTATION: A 14-year-old male with NBS presented with persistent abdominal pain and was diagnosed with primary Hodgkin disease of the stomach. CONCLUSIONS: In pediatric patients with predisposition to malignancies, such as those with underlying chromosome instability disorders, all symptoms must be carefully considered.

Diagnostic and therapeutic approach to children with Nijmegen breakage syndrome in relation to development of lymphoid malignancies.

INTRODUCTION AND OBJECTIVE: Nijmegen breakage syndrome (NBS) is a rare chromosomal instability disorder. The majority of patients carry founder mutation in the NBN gene (c.657_661del5). Characteristic features of the NBS include progressive microcephaly, dysmorphic facial features, immunodeficiency, and high predisposition to malignancy with cumulative cancer incidence by the age of 20 years, and amounted to over 70%. The aim of study is to present the latest methods of diagnosis, potential cancer risk factors and treatment of lymphoid malignancies in children with NBS. REVIEW METHODS: To review the evidence using PubMed and Google Scholar search which included articles published between 2009-2021, focusing on articles published between 2013-2021. ABBREVIATED DESCRIPTION OF THE STATE OF KNOWLEDGE: The average delay in diagnosis of NBS ranges from 4-5 years. Neonatal screening of T-cell excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs) seems favourable in NBS. There are no specific protocols for the treatment of lymphoid malignancies in children with NBS, and full- dose chemotherapy is the most frequently applied method. Reducing the doses of chemotherapy does not significantly reduce the toxicity. Main cause of death is cancer progression and treatment-related mortality mostly associated with infectious complications. Patients with diagnosed cancer who received haematopoietic stem cell transplantation (HSCT) had significantly higher 20-year OS than those who did not (42.7% vs. 30.3%). SUMMARY: Further meta-analysis is essential to establish the best monitoring and treatment regimen in patients with NBS and lymphoid malignancies.

Bilateral Ovarian Germ Cell Tumor in a 46,XX Female with Nijmegen Breakage Syndrome and Hypergonadotropic Hypogonadism

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disease, affecting mainly patients of Slavic origin. It is caused by a defect in the NBN gene, resulting in defective nibrin protein formation. This leads to chromosomal instability, which predisposes to cancer, with lymphoid malignancies predominating. Nibrin is also involved in gonadal development and its disfunction in females with NBS frequently results in a pure gonadal dysgenesis (PGD) causing hypergonadotropic hypogonadism. However, only a few ovarian tumors in NBS patients have been reported to date. We describe the first case of a girl with NBS with PGD, who developed metachronous bilateral ovarian germ cell tumors (dysgerminoma and gonadoblastoma). Pathogenesis of PGD, neoplastic transformation and therapeutic approach in females with NBS are discussed.

Treosulfan-Based Conditioning Regimen in Haematopoietic Stem Cell Transplantation with TCRαß/CD19 Depletion in Nijmegen Breakage Syndrome.

Nijmegen breakage syndrome (NBS) is a DNA repair disorder characterized by combined immunodeficiency and a high predisposition to malignancies. HSCT appears to cure immunodeficiency, but remains challenging due to limited experience in long-term risks of transplant-associated toxicity and malignancies. Twenty NBS patients received 22 allogeneic HSCTs with TCRαß/CD19+ graft depletion with fludarabine 150 mg/m2, cyclophosphamide 20-40 mg/kg and thymoglobulin 5 mg/kg based conditioning regimens (CRs). Twelve patients additionally received low-dose busulfan 4 mg/kg (Bu group) and 10 patients (including 2 recipients of a second HSCT) treosulfan (Treo group) 30 g/m2. Overall and event-free survival were 0.75 vs 1 (p = 0.16) and 0.47 vs 0.89 (p = 0.1) in the Bu and Treo groups, respectively. In the Bu group, four patients developed graft rejection, and three died: two died of de novo and relapsed lymphomas and one died of adenoviral hepatitis. The four living patients exhibited split chimerism with predominantly recipient myeloid cells and predominantly donor T and B lymphocytes. In Treo group, one patient developed rhabdomyosarcoma. There was no difference in the incidence of GVHD, viral reactivation, or early toxicity between either group. Low-dose Bu-containing CR in NBS leads to increased graft failure and low donor myeloid chimerism. Treo-CR followed by TCRαß/CD19-depleted HSCT demonstrates a low level of early transplant-associated toxicity and enhanced graft function with stable donor chimerism.

Nijmegen breakage syndrome: case report and review of literature.

Nijmegen Breakage Syndrome (NBS) is a rare autosomalrecessive DNA repair disorder characterized by genomic instability andincreased risk of haematopoietic malignancies observed in morethan 40% of the patients by the time they are 20 years old. The underlying gene, NBS1, is located on human chromosome 8q21 and codes for a protein product termed nibrin, Nbs1 or p95. Over 90% of patients are homozygous for a founder mutation: a deletion of five base pairs which leads to a frame shift and protein truncation. Nibrin (NBN) plays an important role in the DNA damage response (DDR) and DNA repair. DDR is a crucial signalling pathway in apoptosis and senescence. Cardinal symptoms of Nijmegen breakage syndrome are characteristic: microcephaly, present at birth and progressive with age, dysmorphic facial features, mild growth retardation, mild-to-moderate intellectual disability, and, in females, hypergonadotropic hypogonadism. Combined cellular and humoral immunodeficiency with recurrent sino-pulmonary infections, a strong predisposition to develop malignancies (predominantly of lymphoid origin) and radiosensitivity are other integral manifestations of the syndrome. The diagnosis of NBS is initially based on clinical manifestations and is confirmed by genetic analysis. Prenatal molecular genetic diagnosis is possible if disease-causing mutations in both alleles of the NBN gene are known. No specific therapy is available for NBS; however, hematopoietic stem cell transplantation may be one option for some patients. Prognosis is generally poor due to the extremely high rate of malignancies. We present here a case of Nijmegen breakage syndrome associated with Hodgkin lymphomas and Combined variable immunodeficiency.

DNA repair functional analyses of NBN hypomorphic variants associated with NBN-related infertility.

Nijmegen breakage syndrome caused by biallelic pathogenic variants of the DNA-damage response gene NBN, is characterized by severe microcephaly, cancer proneness, infertility, and karyotype abnormalities. We previously reported NBN variants in siblings suffering from fertility defects. Here, we identify a new founder NBN variant (c.442A>G, p.(Thr148Ala)) in Lebanese patients associated with isolated infertility. Functional analyses explored preserved or altered functions correlated with their remarkably mild phenotype. Transcript and protein analyses supported the use of an alternative transcript with in-frame skipping of exons 4-5, leading to p84-NBN protein with a preserved forkhead-associated (FHA) domain. The level of NBN was dramatically reduced and the MRN complex delocalized to the cytoplasm. Interestingly, ataxia-elangiectasia mutated (ATM) also shifted from the nucleus to the cytoplasm, suggesting some interaction between ATM and the MRN complex at a steady state. The ATM pathway activation, attenuated in typical patients with NBS, appeared normal under camptothecin treatment in these new NBN-related infertile patients. Cell cycle checkpoint defect was present in these atypical patients, although to a lesser extent than in typical patients with NBS. In conclusion, we report three new NBN-related infertile patients and we suggest that preserved FHA domain could be responsible for the mild phenotype and intermediate DNA-damage response defects.

Chromosome instability syndromes.

Fanconi anaemia (FA), ataxia telangiectasia (A-T), Nijmegen breakage syndrome (NBS) and Bloom syndrome (BS) are clinically distinct, chromosome instability (or breakage) disorders. Each disorder has its own pattern of chromosomal damage, with cells from these patients being hypersensitive to particular genotoxic drugs, indicating that the underlying defect in each case is likely to be different. In addition, each syndrome shows a predisposition to cancer. Study of the molecular and genetic basis of these disorders has revealed mechanisms of recognition and repair of DNA double-strand breaks, DNA interstrand crosslinks and DNA damage during DNA replication. Specialist clinics for each disorder have provided the concentration of expertise needed to tackle their characteristic clinical problems and improve outcomes. Although some treatments of the consequences of a disorder may be possible, for example, haematopoietic stem cell transplantation in FA and NBS, future early intervention to prevent complications of disease will depend on a greater understanding of the roles of the affected DNA repair pathways in development. An important realization has been the predisposition to cancer in carriers of some of these gene mutations.

Circulating T Cells of Patients with Nijmegen Breakage Syndrome Show Signs of Senescence.

PURPOSE: The Nijmegen breakage syndrome (NBS) is an inherited genetic disorder characterized by a typical facial appearance, microcephaly, growth retardation, immunodeficiency, and a strong predisposition to malignancies, especially of lymphoid origin. NBS patients have a mutation in the NBN gene which involves the repair of DNA double-strand breaks (DSBs). Here we studied the peripheral T cell compartment of NBS patients with a focus on immunological senescence. METHODS: The absolute numbers and frequencies of the different T cell subsets were determined in NBS patients from young age till adulthood and compared to age-matched healthy individuals (HI). In addition, we determined the expression of senescent T cell markers and the signal joint T cell receptor excision circles (sjTRECs) content. RESULTS: Our results demonstrate that NBS patients have reduced T cell numbers. NBS patients showed lower numbers of αß+ T cells, but normal γδ+ T cell numbers compared to HI. Concerning the αß+ T cells, both CD4+ as well as CD8+ T cells were excessively reduced in numbers compared to aged-matched HI. In addition, NBS patients showed higher frequencies of the more differentiated T cells expressing the senescent cell marker CD57 and did not express co-stimulatory molecule CD28. These effects were already present in the youngest age group. Furthermore, NBS patients showed lower sjTREC content in their T cells possibly indicative of a lower thymic output. CONCLUSIONS: We conclude that circulating T cells from NBS patients show signs of a senescent phenotype which is already present from young age on and which might explain their T cell immune deficiency.

Clinical course and therapeutic implications for lymphoid malignancies in Nijmegen breakage syndrome.

Nijmegen breakage syndrome (NBS, MIM #251260) is an autosomal recessive chromosomal instability disorder. Majority of patients affected are of Slavic origin and share the same founder mutation of 657del5 within the NBN gene encoding protein involved in DNA double-strand breaks repair. Clinically, this is characterized by a microcephaly, immunodeficiency and a high incidence of pediatric malignancies, mostly lymphomas and leukemias. Anticancer treatment among patients with NBS is challenging because of a high risk of life threatening therapy-related toxicity including severe infections, bone marrow failure, cardio- and nephrotoxicity and occurrence of secondary cancer. Based on systemic review of available literature and the Polish acute lymphoblastic leukemia database we concluded that among patients with NBS, these who suffered from clinically proven severe immunodeficiency are at risk of the complications associated with oncological treatment. Thus, in this group it reasonable to reduce chemotherapy up to 50% especially concerning anthracyclines methotrexate, alkylating agents and epipodophyllotoxines, bleomycin and radiotherapy should be omitted. Moreover, infection prophylaxis using intravenous immunoglobulin supplementation together with antifungal and antibacterial agent is recommended. To replace radiotherapy or some toxic anticancer agents targeted therapy using monoclonal antibodies and kinase inhibitors or bone marrow transplantation with reduced-intensity conditioning should be considered in some cases, however, this statement needs further studies.

Nijmegen Breakage Syndrome: Clinical and Immunological Features, Long-Term Outcome and Treatment Options - a Retrospective Analysis.

PURPOSE: Nijmegen Breakage Syndrome (NBS) is a rare inherited condition, characterized by microcephaly, chromosomal instability, immunodeficiency, and predisposition to malignancy. This retrospective study, characterizing the clinical and immunological status of patients with NBS at time of diagnosis, was designed to assess whether any parameters were useful in disease prognosis, and could help determine patients qualified for hematopoietic stem cell transplantation. METHODS: The clinical and immunological characteristics of 149 NBS patients registered in the online database of the European Society for Immune Deficiencies were analyzed. RESULTS: Of the 149 NBS patients, 91 (61%), of median age 14.3 years, remained alive at the time of analysis. These patients were clinically heterogeneous, with variable immune defects, ranging from negligible to severe dysfunction. Humoral deficiencies predisposed NBS patients to recurrent/chronic respiratory tract infections and worsened long-term clinical prognosis. Eighty malignancies, most of lymphoid origin (especially non-Hodgkin's lymphomas), were diagnosed in 42% of patients, with malignancy being the leading cause of death in this cohort. Survival probabilities at 5, 10, 20 and 30 years of age were 95, 85, 50 and 35%, respectively, and were significantly lower in patients with than without malignancies. CONCLUSIONS: The extremely high incidence of malignancies, mostly non-Hodgkin's lymphomas, was the main risk factor affecting survival probability in NBS patients. Because treatment of NBS is very difficult and frequently unsuccessful, the search for an alternative medical intervention such as hematopoietic stem cell transplantation is of great clinical importance.

Nijmegen breakage syndrome detected by newborn screening for T cell receptor excision circles (TRECs).

PURPOSE: Severe combined immunodeficiency (SCID) encompasses a group of disorders characterized by reduced or absent T-cell number and function and identified by newborn screening utilizing T-cell receptor excision circles (TRECs). This screening has also identified infants with T lymphopenia who lack mutations in typical SCID genes. We report an infant with low TRECs and non-SCID T lymphopenia, who proved upon whole exome sequencing to have Nijmegen breakage syndrome (NBS). METHODS: Exome sequencing of DNA from the infant and his parents was performed. Genomic analysis revealed deleterious variants in the NBN gene. Confirmatory testing included Sanger sequencing and immunoblotting and radiosensitivity testing of patient lymphocytes. RESULTS: Two novel nonsense mutations in NBN were identified in genomic DNA from the family. Immunoblotting showed absence of nibrin protein. A colony survival assay demonstrated radiosensitivity comparable to patients with ataxia telangiectasia. CONCLUSIONS: Although TREC screening was developed to identify newborns with SCID, it has also identified T lymphopenic disorders that may not otherwise be diagnosed until later in life. Timely identification of an infant with T lymphopenia allowed for prompt pursuit of underlying etiology, making possible a diagnosis of NBS, genetic counseling, and early intervention to minimize complications.

[Ocular findings in Nijmegen breakage syndrome]. / Objawy okulistyczne w przebiegu zespolu Nijmegen.

UNLABELLED: Nijmegen Breakage Syndrome (NBS) is a genomic instability disease caused by inherited mutations in the NBN/NBS1 gene. The clinical symptoms of NBS are: primary microcephaly, characteristic facial appearance, recurring respiratory tract infections caused by immune deficiency and extremely high risk of cancer development at early age. PURPOSE: The aim of the study was to assess the vision organ in patients with NBS. MATERIAL AND METHODS: Ophthalmological examination of 10 NBS patients was performed. The visual acuity, refractive errors, anterior and posterior segment of the eye ball test, tonometry and biometry were assessed. RESULTS: Serious pathology of the sight organ in the study group were found, including upward slanting of the palpebral fissures, reduced visual acuity, small eyes, small cornea diameter, lens opacity, refractive errors. CONCLUSIONS: The patients with Nijmegen breakage syndrome have significant sight organ abnormalities. These pathologies require long-term ophthalmologic care.

Síndrome de Nijmegen: una enfermedad genética a considerar en un paciente con microcefalia, retardo mental y lesiones de la piel / Nijmegen breakage syndrome

Se presenta el caso de un paciente masculino que a los 6 años de edad es derivado a Neurología Infantil para su estudio por presentar microcefalia y retardo mental. Tras ser evaluado por Inmunología y Genética se realiza en el Laboratorio de citogenética humana, programa de genética ICBM, Facultad de Medicina Universidad de Chile, PCR para deleción 657 del5 que confirma el diagnóstico de Nijmegen dando como resultado deleción nucleótido 5, mutación 657 del5, característico del Síndrome de Nijmegen. Actualmente el niño tiene 13 años y es tratado en el Servicio de Oncología infantil por el desarrollo de linfoma difuso de células grandes B, patología frecuente en este sindrome.

A case of a male patient at 6 years old was referred to child neurology for study due to microcephaly and mental retardation. After being evaluated for Immunology and Genetics Laboratory is performed in human cytogenetics, genetic program ICBM, Faculty of Medicine University of Chile, PCR for deletion 657 of the 5 that confirms the diagnosis of Nijmegen nucleotide deletion resulting in 5, 657 mutation del 5 Characteristic of the syndrome of Nijmegen. Currently the child is 13 and is treated at the Children’s Oncology Service in the development of lymphoma diffuse large B cell, common pathology in this syndrome.

Nijmegen breakage syndrome complicated with primary cutaneous tuberculosis.

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive chromosomal instability syndrome characterized by severe immunodeficiency, growth retardation, microcephaly, a distinct facial appearance, and a high predisposition to lymphoid malignancy. We report a 7-year-old white girl with NBS associated with cutaneous tuberculosis. The patient presented with multiple red-brown, centrally scaring plaques on the leg and had neither pulmonary nor systemic manifestation of tuberculosis. Polymerase chain reaction testing using Mycobacterium genus- and Mycobacterium tuberculosis species-specific primers confirmed the clinical diagnosis of cutaneous tuberculosis. This is the first report describing the simultaneous presentation of NBS and cutaneous tuberculosis.

Chronic noninfectious necrotizing granulomas in a child with Nijmegen breakage syndrome.

Nijmegen breakage syndrome (NBS) is a chromosomal breakage disorder with characteristic physical features, chromosomal instability, and combined immunodeficiency. It is closely related to other chromosomal breakage disorders like ataxia telangiectasia. Noninfectious granulomatous inflammation refractory to treatment is a relatively common feature in ataxia telangiectasia. Herein we report a patient with NBS who developed chronic refractory necrotizing granulomatous ulcerations and review the pathophysiology of NBS and noninfectious granulomas in primary immunodeficiency syndromes.

[Nijmegen Breakage syndrome]. / Nijmegen-Breakage-szindróma.

Nijmegen Breakage syndrome is a rare, autosomal recessive disorder characterized by severe, combined immunodeficiency, recurrent sinopulmonary infections, chromosomal instability, radiosensitivity, predisposition to malignancy, a "bird-like" facial appearance, progressive microcephaly, short stature, and mental retardation. The syndrome is caused by mutations in the NBS1 gene, which encodes a DNA-repair protein, named nibrin. The authors summarize current knowledge on molecular genetics, diagnostic characteristics and therapeutic options of this inborn error of innate immunity.

Speech impairment in Nijmegen breakage syndrome: a rare anomaly.

The subject of the case study was a 13 years old girl with Nijmegen breakage syndrome (NBS), having mild mental retardation and age inappropriate language skills. The case demonstrated severely delayed receptive and expressive language skills. The symptoms of NBS including congenital microcephaly, mild dysmorphic facial appearance, growth retardation, short stature, mental retardation, chromosome instability, speech and language delay were present in our case. Therefore treatment efforts were directed towards general speech and language stimulation techniques, expanding communicative intentions expressed, strengthening oro-facial musculature for articulatory precision, speech intensity and intelligibility. The client showed relatively better results over a short period of time. The favorable outcome of the present study provides an important example of the beneficial effects of therapy even for clients with poor prognosis.