A GP1BA Variant in a Czech Family with Monoallelic Bernard-Soulier Syndrome.

Bernard-Soulier syndrome (BSS) is a rare inherited disorder characterized by unusually large platelets, low platelet count, and prolonged bleeding time. BSS is usually inherited in an autosomal recessive (AR) mode of inheritance due to a deficiency of the GPIb-IX-V complex also known as the von Willebrand factor (VWF) receptor. We investigated a family with macrothrombocytopenia, a mild bleeding tendency, slightly lowered platelet aggregation tests, and suspected autosomal dominant (AD) inheritance. We have detected a heterozygous GP1BA likely pathogenic variant, causing monoallelic BSS. A germline GP1BA gene variant (NM_000173:c.98G > A:p.C33Y), segregating with the macrothrombocytopenia, was detected by whole-exome sequencing. In silico analysis of the protein structure of the novel GPIbα variant revealed a potential structural defect, which could impact proper protein folding and subsequent binding to VWF. Flow cytometry, immunoblot, and electron microscopy demonstrated further differences between p.C33Y GP1BA carriers and healthy controls. Here, we provide a detailed insight into its clinical presentation and phenotype. Moreover, the here described case first presents an mBSS patient with two previous ischemic strokes.

Clinical features and survival of patients with indolent systemic mastocytosis defined by the updated WHO classification.

BACKGROUND: In indolent systemic mastocytosis (ISM), several risk factors of disease progression have been identified. Previous studies, performed with limited patient numbers, have also shown that the clinical course in ISM is stable and comparable to that of cutaneous mastocytosis (CM). The aim of this project was to compare the prognosis of patients with ISM with that of patients with CM. METHODS: We employed a dataset of 1993 patients from the registry of the European Competence Network on Mastocytosis (ECNM) to compare outcomes of ISM and CM. RESULTS: We found that overall survival (OS) is worse in ISM compared to CM. Moreover, in patients with typical ISM, bone marrow mastocytosis (BMM), and smoldering SM (SSM), 4.1% of disease progressions have been observed (4.9% of progressions in typical ISM group, 1.7% in BMM, and 9.4% in SSM). Progressions to advanced SM were observed in 2.9% of these patients. In contrast, six patients with CM (1.7%) converted to ISM and no definitive progression to advanced SM was found. No significant differences in OS and event-free survival (EFS) were found when comparing ISM, BMM, and SSM. Higher risk of both progression and death was significantly associated with male gender, worse performance status, and organomegaly. CONCLUSION: Our data confirm the clinical impact of the WHO classification that separates ISM from CM and from other SM variants.

Novel genetic variant of HPS1 gene in Hermansky-Pudlak syndrome with fulminant progression of pulmonary fibrosis: a case report.

BACKGROUND: Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder that is associated with oculocutaneous albinism, bleeding diathesis, granulomatous colitis, and highly penetrant pulmonary fibrosis in some subtypes. Homozygous or compound heterozygous pathological variants in HPS1, HPS3, HPS4, and several other genes lead to clinical manifestation of the disease. CASE PRESENTATION: A 57-year-old female was admitted with congenital oculocutaneous albinism, thrombocytopathy and late-onset accelerated pulmonary fibrosis (first symptoms from age 50 onwards). Chest high-resolution computed tomography identified thickening of peribronchovascular interstitium, bronchiectasis, reticulations, honeycombing, ground glass opacities and lung parenchyma consolidations. HPS was clinically suspected. We performed whole exome sequencing (WES), a form of massive parallel sequencing, of proband-parents trio. Whole exome libraries were processed using KAPA Hyper Prep Kit, SeqCap EZ MedExome Enrichment Kit and HyperCap Bead Kit according to the SeqCap EZ HyperCap Workflow. The paired-end 2 × 75 bp sequencing was performed on the Illumina NextSeq 500 Sequencer (Illumina Inc., USA). Furthermore, obtained variants by WES were evaluated using a virtual panel of genes: HPS1, AP3B1, HPS3, HPS4, HPS5, HPS6, DTNBP1, BLOC1S3, and PLDN. We identified a compound heterozygous genotype in HPS1 gene in the proband. We identified a pathogenic frameshift variant c.1189delC; p.(Gln397Serfs*2), resulting in a premature stop codon. This variant has been previously associated with HPS. Furthermore, we characterized previously undescribed nonsense variant c.1507C > T; p.(Gln503*), resulting in a premature stop codon and mRNA degradation through nonsense-mediated decay. Sanger sequencing validated the presence of both variants and simultaneously confirmed the heterozygous carrier status of parents. Unfortunately, the patient died due to fulminant progression of pulmonary fibrosis 2 months after diagnostics. CONCLUSIONS: Compound heterozygous mutations in HPS1 in the proband lead to disruption of HPS1 gene and clinical manifestation of HPS with severe pulmonary fibrosis. This case illustrates the need to consider HPS in differential diagnostics of pulmonary fibrosis. Pulmonary fibrosis is a common cause of death in HPS patients. Earlier diagnosis may enable better treatment for these patients.

A novel germline mutation in GP1BA gene N-terminal domain in monoallelic Bernard-Soulier syndrome.

Mutations in the GP1BA gene have been associated with platelet-type von Willebrand disease and Bernard-Soulier syndrome. Here, we report a novel GP1BA mutation in a family with autosomal dominant macrothrombocytopenia and mild bleeding. We performed analyses of seven family members. Using whole-exome sequencing of germline DNA samples, we identified a heterozygous single-nucleotide change in GP1BA (exone2:c.176T>G), encoding a p.Leu59Arg substitution in the N-terminal domain, segregating with macrothrombocytopenia. This variant has not been previously reported. We also analysed the structure of the detected sequence variant in silico. In particular, we used the crystal structure of the human platelet receptor GP Ibα N-terminal domain. Replacement of aliphatic amino-acid Leu 59 with charged, polar and larger arginine probably disrupts the protein structure. An autosomal dominant mode of inheritance, a family history of mild bleeding episodes, aggregation pattern in affected individuals together with evidence of mutation occurring in part of the GP1BA gene encoding the leucine-rich repeat region suggest a novel variant causing monoallelic Bernard-Soulier syndrome.

Ofatumumab added to dexamethasone in patients with relapsed or refractory chronic lymphocytic leukemia: Results from a phase II study.

The treatment of relapsed/refractory chronic lymphocytic leukemia (CLL) remains a challenging clinical issue. An important treatment option is the use of high-dose corticosteroids. The purpose of this clinical trial was to determine the efficacy and toxicity of an ofatumumab-dexamethasone (O-Dex) combination in relapsed or refractory CLL. The trial was an open-label, multicenter, nonrandomized, Phase II study. The O-Dex regimen consisted of intravenous ofatumumab (Cycle 1: 300 mg on day 1, 2,000 mg on days 8, 15, and 22; Cycles 2-6: 1,000 mg on days 1, 8, 15, and 22) and oral dexamethasone (40 mg on days 1-4 and 15-18; Cycles 1-6). The O-Dex regimen was given until best response, or a maximum of six cycles. Thirty-three patients (pts) were recruited. Twenty-four (73%) pts completed at least three cycles of therapy. The remaining nine pts were prematurely discontinued owing to Grade 3/4 infections (seven pts), disease progression (one pt), or uncontrollable diabetes mellitus (one pt). Overall response rates/complete remissions (ORR/CR) were achieved in 22/5 pts (67/15%). The median progression-free survival (PFS) was 10 months. In pts with p53 defects (n = 8), ORR/CR were achieved in 5/2 pts (63/25%) with a median PFS of 10.5 months. The median overall survival (OS) was 34 months. The Grades 3-5 infectious toxicity in 33% of pts represented the most frequent side effect during the treatment period. In conclusion, the O-Dex regimen shows a relatively high ORR and CR with promising findings for PFS and OS. The study was registered at www.clinicaltrials.gov (NCT01310101).

Extensive, 3.8 Mb-Sized Deletion of 22q12 in a Patient with Bilateral Schwannoma, Intellectual Disability, Sensorineural Hearing Loss, and Epilepsy.

Introduction: In contrast with the well-known and described deletion of the 22q11 chromosome region responsible for DiGeorge syndrome, 22q12 deletions are much rarer. Only a few dozen cases have been reported so far. This region contains genes responsible for cell cycle control, chromatin modification, transmembrane signaling, cell adhesion, and neural development, as well as several cancer predisposition genes. Case Presentation: We present a patient with cleft palate, sensorineural hearing loss, vestibular dysfunction, epilepsy, mild to moderate intellectual disability, divergent strabism, pes equinovarus, platyspondylia, and bilateral schwannoma. Using Microarray-based Comparative Genomic Hybridization (aCGH), we identified the de novo 3.8 Mb interstitial deletion at 22q12.1→22q12.3. We confirmed deletion of the critical NF2 region by MLPA analysis. Discussion: Large 22q12 deletion in the proband encases the critical NF2 region, responsible for development of bilateral schwannoma. We compared the phenotype of the patient with previously reported cases. Interestingly, our patient developed cleft palate even without deletion of the MN1 gene, deemed responsible in previous studies. We also strongly suspect the DEPDC5 gene deletion to be responsible for seizures, consistent with previously reported cases.

Diagnosis of Bloom Syndrome in a Patient with Short Stature, Recurrence of Malignant Lymphoma, and Consanguineous Origin.

Bloom syndrome is an autosomal recessive disorder characterized by prenatal and postnatal growth deficiency, photosensitive skin changes, immune deficiency, insulin resistance, and a greatly increased risk of early-onset cancer and development of multiple malignancies. Loss-of-function variants of the BLM gene, which codes for a RecQ helicase, cause Bloom syndrome. We report a consanguineous family, with 2 siblings showing clinical signs of suspected chromosome breakage disorder. One of them developed recurrent malignant lymphoma during lifetime. We performed next-generation sequencing analysis, focusing on cancer predisposition syndromes. We identified a homozygous pathogenic nonsense variant c.1642C>T (p.Gln548*) in the BLM gene in the proband, associated with Bloom syndrome. Sanger sequencing validated the presence of a homozygous pathogenic variant in the proband and also in the brother with short stature. In this article, we will focus on the clinical presentation of the syndrome in this particular family as well as the characteristics of malignancies found in the proband.

A novel germline mutation of the SFTPA1 gene in familial interstitial pneumonia.

Different genes related to alveolar stability have been associated with familial interstitial pneumonia (FIP). Here, we report a novel, rare SFTPA1 variant in a family with idiopathic interstitial pneumonia (IIP). We performed whole-exome sequencing on germline DNA samples from four members of one family; three of them showed signs of pulmonary fibrosis (idiopathic interstitial pneumonia) with autosomal-dominant inheritance. A heterozygous single nucleotide variant c.532 G > A in the SFTPA1 gene has been identified. This variant encodes the substitution p.(Val178Met), localized within the carbohydrate recognition domain of surfactant protein A and segregates with the genes causing idiopathic interstitial pneumonia. This rare variant has not been previously reported. We also analyzed the detected sequence variant in the protein structure in silico. The replacement of valine by the larger methionine inside the protein may cause a disruption in the protein structure. The c.532 G > A variant was further validated using Sanger sequencing of the amplicons, confirming the diagnosis in all symptomatic family members. Moreover, this variant was also found by Sanger sequencing in one other symptomatic family member and one young asymptomatic family member. The autosomal-dominant inheritance, the family history of IIP, and the evidence of a mutation occurring in part of the SFTPA1 gene all suggest a novel variant that causes FIP.

C-terminal RUNX1 mutation in familial platelet disorder with predisposition to myeloid malignancies.

Here we report a C-terminal RUNX1 mutation in a family with platelet disorder and predisposition to myeloid malignancies. We identified the mutation c.866delG:p.Gly289Aspfs*22 (NM_001754) (RUNX1 b-isoform NM_001001890; c.785delG:p.Gly262Aspfs*22) using exome sequencing of samples obtained from eight members of a single family. The mutation found in our pedigree is within exon eight and the transactivation domain of RUNX1. One of the affected individuals developed myelodysplastic syndrome (MDS), which progressed to acute myelogenous leukemia (AML). A search for the second hit which led to the development of MDS and later AML in this individual revealed the PHF6 gene variant (exon9:c.872G > A:p.G291E; NM_001015877), BCORL1 (exon3:c.1111A > C:p.T371P; NM_001184772) and BCOR gene variant (exon4:c.2076dupT:p.P693fs; NM_001123383), which appear to be very likely second hits participating in the progression to myeloid malignancy.

Analysis of prognostic significance of merkel cell polyomavirus in chronic lymphocytic leukemia.

BACKGROUND: Merkel cell polyomavirus (MCPyV), a ubiquitous DNA tumor virus, has been found to be associated with Merkel cell carcinoma and chronic lymphocytic leukemia (CLL). Previous studies have reported conflicting results on the frequency and potential pathogenetic role of MCPyV in CLL. The aim of this study was to evaluate MCPyV's association with CLL and its prognostic significance. PATIENTS AND METHODS: Between 2006 and 2013, DNA samples obtained from CLL patients (n = 119) before treatment were tested for MCPyV using quantitative real-time polymerase chain reaction analysis and verified by gel electrophoresis. Only samples testing positive by both methods were considered valid. RESULTS: We found that 13 (11%) of 119 CLL cases were positive for MCPyV. Between the groups of MCPyV-positive and -negative patients, there was no significant difference in the sex, age, cytogenetics, presence of p53 defect, or immunoglobulin heavy chain (IGHV) mutational status. In the subset of MCPyV-negative patients, advanced Rai stage (III to IV) was found more frequently, and therapy was initiated more often. There was no difference in overall response rate, median progression-free survival, and overall survival between both groups. We did not observe any new positivity after treatment in initially MCPyV-negative patients. CONCLUSION: This study provides the first analysis of the prognostic role of MCPyV in CLL. MCPyV occurrence seems to be a relatively rare event during the course of CLL. MCPyV is also unlikely to influence the outcome of CLL patients.