Here we describe a 10-year-old girl with combined immunodeficiency presenting as recurring chest infections, lung disease and herpetic skin infections. The patient experienced two hematopoietic stem ...cell transplantations and despite full chimerism, she developed bone marrow aplasia due to adenovirus infection and died at post-transplant day 86. Immunologic investigation revealed low numbers of TRECs/KRECs, a severe reduction of memory B cells, absence of isohemagglutinins, and low IgG levels. Whole exome sequencing (WES) identified a novel heterozygous mutation in RAC2(c.275A > C, p.N92 T). Flow cytometric investigation of neutrophil migration demonstrated an absence of chemotaxis to fMLP. Cell lines transfected with RAC2 N92 T displayed characteristics of active GTP-bound RAC2 including enhanced NADPH oxidase-derived superoxide production both at rest and in response to PMA.
Our findings broaden the clinical picture of RAC2 dysfunction, showing that some individuals can present with a combined immunodeficiency later in childhood rather than a congenital neutrophil disease.
•We report a new case of heterozygous RAC2 deficiency, with the clinical presentation of recurrent respiratory infections, lung disease and susceptibility to varicella and herpetic infections.•Our report expands the phenotypic spectrum of RAC2 deficiency•Dominant activating mutations in RAC2 gene can lead to presentations of combined immunodeficiency where both myeloid and lymphoid lineages are affected
Nijmegen breakage syndrome (NBS) is a DNA repair disorder characterized by combined immunodeficiency and a high predisposition to lymphoid malignancies. The majority of NBS patients are identified ...with a homozygous five base pair deletion in the
(
gene (c.657_661del5, p.K219fsX19) with a founder effect observed in Caucasian European populations, especially of Slavic origin. We present here an analysis of a cohort of 136 NBS patients of Eastern Slav origin across Belarus, Ukraine, Russia, and Latvia with a focus on understanding the geographic distribution, incidence of malignancy, and treatment outcomes of this cohort. Our analysis shows that Belarus had the highest prevalence of NBS (2.3 per 1,000,000), followed by Ukraine (1.3 per 1,000,000), and Russia (0.7 per 1,000,000). Of note, the highest concentration of NBS cases was observed in the western regions of Belarus and Ukraine, where NBS prevalence exceeds 20 cases per 1,000,000 people, suggesting the presence of an "Eastern Slavic NBS hot spot." The median age at diagnosis of this cohort ranged from 4 to 5 years, and delay in diagnosis was more pervasive in smaller cities and rural regions. A total of 62 (45%) patients developed malignancies, more commonly in males than females (55.2 vs. 34.2%;
=0.017). In 27 patients, NBS was diagnosed following the onset of malignancies (mean age: 8 years). Malignancies were mostly of lymphoid origin and predominantly non-Hodgkin lymphoma (NHL) (
=42, 68%); 38% of patients had diffuse large B-cell lymphoma. The 20-year overall survival rate of patients with malignancy was 24%. However, females with cancer experienced poorer event-free survival rates than males (16.6% vs. 46.8%,
=0.036). Of 136 NBS patients, 13 underwent hematopoietic stem cell transplantation (HSCT) with an overall survival of 3.5 years following treatment (range: 1 to 14 years). Indications for HSCT included malignancy (
=7) and immunodeficiency (
=6). Overall, 9% of patients in this cohort reached adulthood. Adult survivors reported diminished quality of life with significant physical and cognitive impairments. Our study highlights the need to improve timely diagnosis and clinical management of NBS among Eastern Slavs. Genetic counseling and screening should be offered to individuals with a family history of NBS, especially in hot spot regions.
We characterised the expansion, phenotype and functional activity of natural killer (NK) cells obtained for a clinical trial. Nineteen expansion procedures were performed to obtain NK cell products ...for 16 patients. NK cells were expanded ex vivo from haploidentical donor peripheral blood mononuclear cells in the presence of the locally generated feeder cell line K-562 with ectopic expression of 4-1BBL and mbIL-21. The median duration of expansion was 18 days (interquartile range 15–19). The median number of live cells yielded was 2.26 × 10
9
(range 1.6–3.4 × 10
9
) with an NK content of 96.6% (range 95.1–97.9%). The median NK cell fold expansion was 171 (range 124–275). NK cell fold expansion depended on the number of seeded NK cells, the initial level of C-myc expression and the initial number of mature and immature NK cells. The majority of expanded NK cells had the phenotype of immature activated cells (NKG2A + , double bright CD56 + + CD16 + + , CD57-) expressing NKp30, NKp44, NKp46, NKG2D, CD69, HLA-DR and CD96. Despite the expression of exhaustion markers, expanded NK cells exhibited high cytolytic activity against leukaemia cell lines, high degranulation activity and cytokine production. There was a noted decrease in the functional activity of NK cells in tests against the patient’s blasts.
In conclusion, NK cells obtained by ex vivo expansion with locally generated K562-41BBL-mbIL21 cells had a relatively undifferentiated phenotype and enhanced cytolytic activity against cancer cell lines. Expansion of NK cells with feeder cells yielded a sufficient quantity of the NK cell product to reach high cell doses or increase the frequency of cell infusions for adoptive immunotherapy. Registered at clinicaltrials.gov as NCT04327037.
Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder, characterized by spontaneous chromosomal instability with predisposition to immunodeficiency and cancer. We present a repeated ...NBS in two sons from one woman after two marriages. We describe the clinical data, cytogenetic, and molecular findings of a prenatally diagnosed fetus, and his brothers with NBS. The first patient developed peripheral T-cell lymphoma at the age of 16 years and died 5 months after the protocol start. The diagnosis of NBS was established after his death. The second patient was born after the fifth pregnancy, third delivery in the second marriage; he developed cortical T-cell leukemia at the age of 3 years, received hematopoietic stem cells transplantation (HSCT) and he is alive now. In a year after repeated NBS case in this family, mother became pregnant again and the mutation was detected in the male fetus after the prenatal diagnosis; the pregnancy was aborted. At the age of 41 years, mother's seventh pregnancy finished by miscarriage. In three months, she was pregnant again, only one mutation in NBN gene was detected during the prenatal diagnostics in the female fetus; healthy female was born at term. To our knowledge, this is the first time to describe the repeated cases of two patients born with Nijmegen breakage syndrome from one mother and two different fathers. This case highlights the value of checking NBN carrier in Belarusian families during genetic counselling.
Ataxia-telangiectasia (AT) is a rare neurodegenerative disease characterized by an early onset ataxia, oculocutaneous telangiectasia, immunodeficiency, recurrent infections, radio-sensitivity, and a ...predisposition to malignancy. We present the case of a child with coexistent AT and trisomy X (47,XXX). We used fluorescent in situ hybridization (FISH) to confirm that this person had 47,XXX karyotype in blood cells, bone marrow, fibroblasts, and buccal smear. Standard cytogenetic studies (not banded) were conducted on blood cells. G-banding analysis was performed on bone marrow cells at the time of the leukemia diagnosis. Flow cytometric investigation of lymphocytes and Sanger sequencing of the
ATM
gene were used for diagnosis confirmation and description. We report the case of an 11-year-old girl at remission after having T cell acute leukemia for 7 years with progressive signs of ataxia-telangiectasia and with additional X chromosome since birth. At the age of 2 years and 7 months, she was diagnosed with pre-T acute leukemia. From the age of four, she had gait abnormalities. AT was established at the age of seven based on clinical signs and laboratory findings (increased alpha fetoprotein—AFP 227) and confirmed by detecting compound heterozygous truncating mutations in the
ATM
gene (p.Y705X and p.L2312I). These genetic findings have not been previously reported in AT and our “double hit” case demonstrates the value of careful clinical evaluation of children with an established genetic diagnosis. Measurement of AFP levels should be considered in patients with neurologic abnormalities after leukemia treatment.
Abstract Introduction Here we present an unusual case of DNA ligase IV deficiency syndrome without dysmorphic facial findings and microcephaly complicated with Epstein–Barr virus-associated large ...B-cell lymphoma with the right lung involvement and a massive brain tumor lesion in a two-year-old female. Methods PID panel was used for sequencing 55 genes. Most genes have > 98% exon coverage including splicing sites. LIG4 gene has 100% exon and splicing site coverage. This was used in Ion Torrent PGM system, the library kit was made by Agilent with Haloplex technology. The sequence analysis software was Alamut, direct sequencing of LIG4 gene was performed after NGS results. Result We identified three heterozygous mutations in LIG4 gene c.2736 + 3delC and c.8 C > T (p.A3V) inherited from mother and c.26C > T (p.T9I) – from father after PID panel sequencing and some additional polymorphisms in ATM , NOD2 and NLRP3 genes. Conclusion This case broadens the clinical spectrum of DNA ligase IV deficiency.
•A new model for the organization of the RUNX1/RUNX1T1 fusion oncogene was developed.•Expression of splicing and NMD genes is deregulated in t(8;21)-positive AML.•Alternative splicing of the ...RUNX1/RUNX1T1 mRNAs follows a power-law behavior.•Alternative splicing is extremely sensitive to targeted skipping of “exons-hubs”.
The t(8;21) translocation is the most widespread genetic defect found in human acute myeloid leukemia. This translocation results in the RUNX1–RUNX1T1 fusion gene that produces a wide variety of alternative transcripts and influences the course of the disease. The rules of combinatorics and splicing of exons in the RUNX1–RUNX1T1 transcripts are not known. To address this issue, we developed an exon graph model of the fusion gene organization and evaluated its local exon combinatorics by the exon combinatorial index (ECI). Here we show that the local exon combinatorics of the RUNX1–RUNX1T1 gene follows a power-law behavior and (i) the vast majority of exons has a low ECI, (ii) only a small part is represented by “exons-hubs” of splicing with very high ECI values, and (iii) it is scale-free and very sensitive to targeted skipping of “exons-hubs”. Stochasticity of the splicing machinery and preferred usage of exons in alternative splicing can explain such behavior of the system. Stochasticity may explain up to 12% of the ECI variance and results in a number of non-coding and unproductive transcripts that can be considered as a noise. Half-life of these transcripts is increased due to the deregulation of some key genes of the nonsense-mediated decay system in leukemia cells. On the other hand, preferred usage of exons may explain up to 75% of the ECI variability. Our analysis revealed a set of splicing-related cis-regulatory motifs that can explain “attractiveness” of exons in alternative splicing but only when they are considered together. Cis-regulatory motifs are guides for splicing trans-factors and we observed a leukemia-specific profile of expression of the splicing genes in t(8;21)-positive blasts. Altogether, our results show that alternative splicing of the RUNX1–RUNX1T1 transcripts follows strict rules and that the power-law component of the fusion gene organization confers a high flexibility to this process.
Background
Omenn syndrome Mendelian Inheritance (OMIM 603554) is a genetic disease of the immune system, characterized by the presence of fatal generalized severe erythroderma, lymphoadenopathy, ...eosinophilia and profound immunodeficiency.
Objective
We studied clinical and immunologic presentation of the disease manifestation among East Slavs population with genetically confirmed Omenn syndrome.
Results
We collected clinical and immunologic data of 11 patients (1 from Belarus, 5 – Ukraine, 5 – Russia): 6 females, 5 males. The age of Omenn syndrome manifestation varied from the 1st day of life to 1 year and 1 month, the age of diagnosis – 20 days to 1 year and 10 months. Nine out of 11 patients had classic immunologic phenotype T(+/−)B-NK+, 1 pt had TlowB + NK+ with CD3 + TCRgd + expansion and 1 had TlowB+/−NK+ phenotype. Eight out of 11 pts had mutation in
RAG1
gene, 4 out of 8 had c.368-369delAA (p.K86fsX118) in homozygous state or heterozygous compound. In our cohort of patients, we also described two new mutations in
RAG
genes (p.E722Q in
RAG1
and p.M459R in
RAG2
). At present, 7/11 were transplanted and 5 out of the transplanted are alive.
Conclusion
This study demonstrates that the most popular genetic abnormality in East Slavs children with Omenn syndrome is c.368-369delAA (p.K86fs118) in
RAG1
gene, which may be connected with more favorable prognosis because 4/4 patients survived after hematopoietic stem cells transplantation.
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