Shwachman-Diamond syndrome

Characteristics of Craniofacial Morphology and Occlusion in Shwachman-Diamond Syndrome: A Case Report of a Japanese Sibling Pair

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder mainly caused by mutations in the Shwachman-Bodian-Diamond syndrome gene on chromosome 7q11. Although skeletal abnormalities are a feature of SDS, no reports have focused on the craniofacial morphology of patients with SDS. Moreover, the detailed dental characteristics of SDS remain unknown. In the present case report, we evaluated the craniofacial morphology and dental findings of two patients with SDS. A Japanese adolescent sibling pair with SDS had the chief complaint of excessive overjet. Cephalometric analysis revealed similar craniofacial morphology in both patients: skeletal class I malocclusion with a hypodivergent pattern and labial inclination of the maxillary and mandibular incisors. A panoramic photograph showed the tendency of delayed permanent tooth eruption and replacement in both patients. These cases suggest that malocclusion requiring orthodontic treatment might be a feature of patients with SDS.

A Rare Case of Exocrine Pancreatic Insufficiency

Lipomatous pseudohypertrophy (LPH) of the pancreas is an uncommon affection of exocrine pancreatic insufficiency. It is defined as substitution of the pancreatic exocrine gland by a large fat component. We report the case of a young patient with malabsorption syndrome (chronic diarrhoea and steatorrhoea), abnormal laboratory results and normal fibroscopy. Computed tomography revealed characteristic diffuse pancreatic abnormalities.

LEARNING POINTS

Computed tomography is key for identifying lipomatous pseudohypertrophy.Malabsorption syndrome is usually associated with lipomatous pseudohypertrophy.A syndromic aetiology should be considered.

Shwachman-Diamond syndrome: Nationwide survey and systematic review in Japan

BACKGROUND

Shwachman-Diamond syndrome (SDS) is a rare multisystem disorder associated with exocrine pancreatic insufficiency. The present study reports the results of a nationwide survey and a systematic review on SDS to develop consensus guidelines for intractable diarrhea including SDS.

METHODS

Questionnaires were sent to 616 departments of pediatrics or of pediatric surgery in Japan in a nationwide survey. A second questionnaire was sent to doctors who had treated SDS patients and included questions on clinical information. Additionally, a systematic review was performed using digital literature databases to assess the influence of medical (i.e. non-surgical) treatment on SDS prognosis.

RESULTS

Answers were received from 529 institutions (85.9%), which included information on 24 patients with SDS (median age, 10.4 years; male, n = 15) treated from January 2005 to December 2014. Although 75% of patients received pancreatic enzyme replacement therapy, there was no significant association between treatment and prognosis. Systematic review identified one clinical practice guideline, two case series, eight case reports and 26 reviews. Patient information from those studies was insufficient for meta-analysis.

CONCLUSIONS

The rarity of SDS makes it difficult to establish evidence-based treatment for SDS. According to the limited information from patients and published reports, medical treatment for malabsorption due to SDS should be performed to improve fat absorption and stool condition, but it is not clear whether this treatment improves the prognosis of malabsorption.

Potential relationship between inadequate response to DNA damage and development of myelodysplastic syndrome

Hematopoietic stem cells (HSCs) are responsible for the continuous regeneration of all types of blood cells, including themselves. To ensure the functional and genomic integrity of blood tissue, a network of regulatory pathways tightly controls the proliferative status of HSCs. Nevertheless, normal HSC aging is associated with a noticeable decline in regenerative potential and possible changes in other functions. Myelodysplastic syndrome (MDS) is an age-associated hematopoietic malignancy, characterized by abnormal blood cell maturation and a high propensity for leukemic transformation. It is furthermore thought to originate in a HSC and to be associated with the accrual of multiple genetic and epigenetic aberrations. This raises the question whether MDS is, in part, related to an inability to adequately cope with DNA damage. Here we discuss the various components of the cellular response to DNA damage. For each component, we evaluate related studies that may shed light on a potential relationship between MDS development and aberrant DNA damage response/repair.

Congenital defects in neutrophil dynamics

Neutrophil granulocytes are key effector cells of the vertebrate immune system. They represent 50-70% of the leukocytes in the human blood and their loss by disease or drug side effect causes devastating bacterial infections. Their high turnover rate, their fine-tuned killing machinery, and their arsenal of toxic vesicles leave them particularly vulnerable to various genetic deficiencies. The aim of this review is to highlight those congenital immunodeficiencies which impede the dynamics of neutrophils, such as migration, cytoskeletal rearrangements, vesicular trafficking, and secretion.

Ribosomal protein mutations induce autophagy through S6 kinase inhibition of the insulin pathway

Mutations affecting the ribosome lead to several diseases known as ribosomopathies, with phenotypes that include growth defects, cytopenia, and bone marrow failure. Diamond-Blackfan anemia (DBA), for example, is a pure red cell aplasia linked to the mutation of ribosomal protein (RP) genes. Here we show the knock-down of the DBA-linked RPS19 gene induces the cellular self-digestion process of autophagy, a pathway critical for proper hematopoiesis. We also observe an increase of autophagy in cells derived from DBA patients, in CD34⁺ erythrocyte progenitor cells with RPS19 knock down, in the red blood cells of zebrafish embryos with RP-deficiency, and in cells from patients with Shwachman-Diamond syndrome (SDS). The loss of RPs in all these models results in a marked increase in S6 kinase phosphorylation that we find is triggered by an increase in reactive oxygen species (ROS). We show that this increase in S6 kinase phosphorylation inhibits the insulin pathway and AKT phosphorylation activity through a mechanism reminiscent of insulin resistance. While stimulating RP-deficient cells with insulin reduces autophagy, antioxidant treatment reduces S6 kinase phosphorylation, autophagy, and stabilization of the p53 tumor suppressor. Our data suggest that RP loss promotes the aberrant activation of both S6 kinase and p53 by increasing intracellular ROS levels. The deregulation of these signaling pathways is likely playing a major role in the pathophysiology of ribosomopathies.

Diseases linked to mutations affecting the ribosome, ribosomopathies, have an exceptionally wide range of phenotypes. However, many ribosomopathies have some features in common including cytopenia and growth defects. Our study aims to clarify the mechanisms behind these common phenotypes. We find that mutations in ribosomal protein genes result in a series of aberrant signaling events that cause cells to start recycling and consuming their own intracellular contents. This basic mechanism of catabolism is activated when cells are starving for nutrients, and also during the tightly regulated process of blood cell maturation. The deregulation of this mechanism provides an explanation as to why blood cells are so acutely affected by mutations in genes that impair the ribosome. Moreover, we find that the signals activating this catabolism are coupled to impairment of the highly conserved insulin-signaling pathway that is essential for growth. Taken together, our in-depth description of the pathways involved as the result of mutations affecting the ribosome increases our understanding about the etiology of these diseases and opens up previously unknown avenues of potential treatment.

The inherited bone marrow failure syndromes

Molecular pathogenesis may be elucidated for inherited bone marrow failure syndromes (IBMFS). The study and presentation of the details of their molecular biology and biochemistry is warranted for appropriate diagnosis and management of afflicted patients and to identify the physiology of the normal hematopoiesis and mechanisms of carcinogenesis. Several themes have emerged within each subsection of IBMFS, including the ribosomopathies, which include ribosome assembly and ribosomal RNA processing. The Fanconi anemia pathway has become interdigitated with the familial breast cancer syndromes. In this article, the diseases that account for most IBMFS diagnoses are analyzed.

Childhood myelodysplastic syndrome

Myelodysplastic syndrome (MDS) comprises of a heterogeneous group of bone marrow disorders resulting from a clonal stem cell defect characterised by cytopenias despite a relatively hypercellular marrow, ineffective hematopoiesis, morphological dysplasia in the marrow elements, no response to hematinics such as iron, B12 or folic acid and risk of progression to leukemia. Myelodysplastic syndrome in childhood is extremely rare and accounts for less than 5% of all hematopoietic neoplasms in children below the age of 14 y. The primary MDS in children, also known as de novo MDS differs from secondary MDS which generally follows congenital or acquired bone marrow (BM) failure syndromes as well as from therapy related MDS, commonly resulting from cytotoxic therapy. MDS associated with Down syndrome which accounts for approximately one-fourth of cases of childhood MDS is now considered a unique biologic entity synonymous with Down syndrome-related myeloid leukemia and is biologically distinct from other cases of childhood MDS. Refractory cytopenia of childhood (RCC) is the commonest type of MDS. Genetic changes predisposing to MDS in childhood remain largely obscure. Monosomy 7 is by-far the commonest cytogenetic abnormality associated with childhood MDS; however most cases of RCC show a normal karyotype. Complex cytogenetic abnormalities and trisomy 8 and trisomy 21 are also occasionally observed. The most effective and curative treatment is Hematopoietic stem cell transplantation and this is particularly effective in children with the monosomy 7 genetic defect as well as those displaying complex karyotype abnormalities provided it is instituted early in the course of the disease.

Imaging findings of lipomatosis: a comprehensive review

Lipomatosis is a benign and non-encapsulated mature form of fat tissue proliferation, which can be isolated or multiple, symmetrical or infiltrative, and may be associated with several syndromes. Lipomatosis has been reported to involve almost every part and organ in the body. In this review, we present imaging findings at common locations of lipomatosis and summarize lipomatosis-related syndromes.

Dermatofibrosarcoma protuberans arising in the context of Shwachman-Diamond syndrome

Dermatofibrosarcoma protuberans (DFSP) is an uncommon malignant spindle-cell tumor usually presenting in adulthood. The epidemiology of DFSP has recently been reviewed, and there have been 152 reported cases of DFSP in patients below the age of sixteen. We present the case of a DFSP arising in a young patient with Shwachman-Diamond syndrome (SDS).

A case of anemia caused by combined vitamin B12 and iron deficiency manifesting as short stature and delayed puberty

Anemia caused by vitamin B12 deficiency resulting from inadequate dietary intake is rare in children in the modern era because of improvements in nutritional status. However, such anemia can be caused by decreased ingestion or impaired absorption and/or utilization of vitamin B12. We report the case of an 18-year-old man with short stature, prepubertal sexual maturation, exertional dyspnea, and severe anemia with a hemoglobin level of 3.3 g/dL. He had a history of small bowel resection from 50 cm below the Treitz ligament to 5 cm above the ileocecal valve necessitated by midgut volvulus in the neonatal period. Laboratory tests showed deficiencies of both vitamin B12 and iron. A bone marrow examination revealed dyserythropoiesis and low levels of hemosiderin particles, and a cytogenetic study disclosed a normal karyotype. After treatment with parenteral vitamin B12 and elemental iron, both anemia and growth showed gradual improvement. This is a rare case that presented with short stature and delayed puberty caused by nutritional deficiency anemia in Korea.

MRI findings in Shwachman diamond syndrome

Shwachman Diamond Syndrome (SDS) is a rare congenital disorder characterized by pancreatic insufficiency, bone marrow dysfunction, and skeletal changes. Because of the heterogeneous clinical presentation and the limits of laboratory tests that assess pancreatic insufficiency, the diagnosis of SDS can be challenging. Pancreatic lipomatosis, a typical feature of this syndrome, is also difficult to assess by direct tissue sampling. In these circumstances, magnetic resonance imaging (MRI) provides a readily available, noninvasive tool to evaluate the pancreatic fat content. We report a case of a 12-month-old male in which abdominal MRI was used to confirm the clinical diagnosis of SDS.

[Diffuse primary fat replacement of the pancreas: an unusual cause of steatorrhea]

Diffuse and primitive fat replacement of the exocrine pancreas is a rare cause of exocrine pancreatic insufficiency in adults. We report two adult patients with chronic diarrhoea and steatorrhea whose morphologic abnormalities revealed diffuse fat replacement of the pancreas. Tomodensitometry detected diffuse characteristic abnormalities with fat intermixed with normal pancreatic lobules or a "vanishing pancreas". In one patient, magnetic resonance imaging and echo-endoscopy suggested abnormalities. Administration of pancreatic extracts improved symptoms.

The Shwachman-Bodian-Diamond syndrome associated protein interacts with HsNip7 and its down-regulation affects gene expression at the transcriptional and translational levels

The Shwachman-Bodian-Diamond syndrome (SDS) is an autosomal disorder with pleiotropic phenotypes including pancreatic, skeletal and bone marrow deficiencies and predisposition to hematological dysfunctions. SDS has been associated to mutations in the SBDS gene, encoding a highly conserved protein that was shown to function in ribosome biogenesis in yeast. In this work, we show that SBDS is found in complexes containing the human Nip7 ortholog. Analysis of pre-rRNA processing in a stable SBDS knock-down HEK293-derivative cell line revealed accumulation of a small RNA which is a further indication of SBDS involvement in rRNA biosynthesis. Global transcription and polysome-bound mRNA profiling revealed that SBDS knock-down affects expression of critical genes involved in brain development and function, bone morphogenesis, blood cell proliferation and differentiation, and cell adhesion. Expression of a group of growth and signal transduction factors and of DNA damage response genes is also affected. In SBDS knock-down cells, 34 mRNAs showed decreased and 55 mRNAs showed increased association to polysomes, among which is a group encoding proteins involved in alternative splicing and RNA modification. These results indicate that SBDS is required for accurate expression of genes important for proper brain, skeletal, and blood cell development.

[Shwachman-Diamond syndrome: clinical manifestations and molecular genetics]

The Shwachman-Diamond syndrome is a rare, autosomal recessive primary immunodeficiency disorder characterized by exocrine pancreatic insufficiency, metaphyseal dysostosis, short stature, bone marrow dysfunction and recurrent infections. The authors summarize current knowledge on molecular pathomechanisms, diagnostic criteria, therapy, and clinical manifestations of the syndrome. They present the first Hungarian patient with Shwachman-Diamond syndrome, in whom mutation analysis was performed. The patient had neutropenia, exocrine pancreatic failure, severe growth retardation, and recurrent skin and respiratory tract infections. Two previously undescribed mutations in the Shwachman-Diamond syndrome gene (c.362A > C, p.N121T and c.523C > T, p.R175W) were found. Recently, the mother became pregnant again and requested prenatal diagnosis, which revealed a carrier status of the c.523C > T, (p.R175W) mutation only, so the mother decided to complete the pregnancy.

Shwachman-Diamond syndrome

Shwachman-Diamond syndrome (SDS) is an autosomal recessive marrow failure syndrome associated with exocrine pancreatic insufficiency and leukemia predisposition. Bone marrow failure typically manifests with neutropenia, but anemia, thrombocytopenia, or aplastic anemia may also develop. Additional organ systems, such as liver or bone, may also be affected. Clonal cytogenetic abnormalities, particularly those involving chromosome 7 such as monosomy 7 or isochromosome 7, may develop. Mutations in the SBDS gene are found in approximately 90% of patients meeting clinical diagnostic criteria. SBDS is a highly conserved gene of unknown function. Studies of the yeast orthologue YLR022c and structurally related proteins suggest a role in RNA metabolism. In human cells, the SBDS protein localizes to both the cytoplasm and the nucleus, and shuttles in and out of the nucleolus in a cell cycle-dependent manner. A discussion of diagnostic workup, medical management, and treatment is presented.

Síndrome de Shwachman-Diamond

Shwachman-Diamond syndrome is a rare autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, skeletal abnormalities, and short stature. We describe the clinical characteristics, laboratory data, and treatment in a 14-month-old boy diagnosed with this syndrome in our unit.

Haematopoietic stem cell transplantation for Shwachman-Diamond disease: a study from the European Group for blood and marrow transplantation

This report assessed the results of allogeneic stem cell transplantation (allo-SCT) in 26 patients with Shwachman-Diamond disease (SDS) and severe bone marrow abnormalities. The conditioning regimen was based on busulphan (54%), total body irradiation (23%), fludarabine (15%) or other chemotherapy combinations (8%). Standard prevention of graft versus host disease (GVHD) with cyclosporin +/- methotrexate was adopted in 54% of the patients whilst in vivo or in vitro T-cell depletion was used in 17 and four patients respectively. Neutrophil and platelet engraftment were achieved in 21 (81%) and 17 (65%) of 26 patients after a median time of 18 days and 29 days respectively. The incidence of grade III and IV acute GVHD was 24% and of chronic GVHD 29%. Nine patients died after a median time of 70 d, post-SCT. After a median follow-up of 1.1 years, the transplant-related mortality was 35.5% (95% CI 17-54) whilst the overall survival was 64.5% (95% CI 45.7-83.2). Allo-SCT was found to be successful in more than half of SDS patients with severe bone marrow dysfunction. Further improvements would be anticipated by a better definition of the optimum time in the course of disease to transplant and by the adoption of less toxic conditioning regimens.

Genetic analysis of Shwachman-Diamond syndrome: phenotypic heterogeneity in patients carrying identical SBDS mutations

Shwachman-Diamond syndrome (SDS) is a rare hereditary disorder characterized by pancreatic exocrine insufficiency, bone marrow dysfunction and skeletal changes. Recently, the cause of SDS was identified as mutations of Shwachman-Bodian-Diamond syndrome gene (SBDS) and most mutations are caused by gene conversion between SBDS and its highly homologous pseudogene. Clinical variations especially in skeletal and bone marrow abnormalities are well known in this syndrome. To study the relationship between SBDS mutation and its clinical features, we analyzed 9 Japanese patients including one sibling and detected the three different SBDS mutations in 7 patients: a mutation that disrupts the donor splice site of intron 2, deletes 8 bp of the exon 2 and produces premature termination (258+2 T > C), a dinucleotide change that replaces a lysine at 62 nd amino acid to a termination codon (183-184 TA > CT), and a 4-bp deletion that causes premature termination by frameshift (292-295 delAAAG). The 5 patients represent compound heterozygotes of the 258+2 T > C and 183-184 TA > CT mutations. One patient is a compound heterozygote of the 258+2 T > C and 292-295 delAAAG mutations, and in the remaining one case only a 258+2 T > C mutation could be detected. Thus, the 258+2 T > C and 183-184 TA > CT mutations are prevalent among Japanese patients. No mutations were found in two cases, despite the clinical features. Of the 7 patients with SBDS mutations, persistent hematologic abnormalities and skeletal changes were not observed in 3 and 2 patients, respectively. Notably, clinical variations are present even among the patients with the identical genotype: compound heterozygotes of the 258+2 T > C and 183-184 TA > CT mutations. Further study will be required to explain the clinical heterogeneity.

Hematologic abnormalities in Shwachman Diamond syndrome: lack of genotype-phenotype relationship

Shwachman-Diamond syndrome (SDS) is an autosomal-recessive disorder characterized by short stature, exocrine pancreatic insufficiency, and hematologic defects. The causative SBDS gene was sequenced in 20 of 23 unrelated patients with clinical SDS. Mutations in the SBDS gene were found in 75%, being identical in 11 patients. Hematologic parameters for all 3 lineages were determined over time such as absolute neutrophil counts (ANCs), granulocyte functions, and erythroid and myeloid colony formation (erythroid burst-forming unit [BFU-E] and granulocyte-monocyte colony-forming unit [CFU-GM]) from hematopoietic progenitor cells, percentage of fetal hemoglobin (HbF), and platelet counts. Persistent neutropenia was present in 43% in the absence of apoptosis and unrelated to chemotaxis defects (in 65%) or infection rate. Irrespective of the ANC in vivo, abnormal CFU-GM was observed in all patients with SDS tested (14 of 14), whereas BFU-E was less often affected (9 of 14). Cytogenetic aberrations occurred in 5 of 19 patients in the absence of myelodysplasia. One child died during allogeneic bone marrow transplantation. In conclusion, neutropenia and defective chemotaxis did not result in severe clinical infection in SDS. CFU-GMs were impaired in all patients tested. From the SBDS sequence data, we conclude that in patients with genetically proven SDS a genotype-phenotype relationship in SDS does not exist in clinical and hematologic terms.

The Shwachman-Diamond SBDS protein localizes to the nucleolus

Shwachman-Diamond syndrome (SDS) is an autosomal recessively inherited disorder characterized by exocrine pancreatic insufficiency and bone marrow failure. The gene for this syndrome, SBDS, encodes a highly conserved novel protein. We characterized Shwachman-Bodian-Diamond syndrome (SBDS) protein expression and intracellular localization in 7 patients with SDS and healthy controls. As predicted by gene mutation, 4 patients with SDS exhibited no detectable full-length SBDS protein. Patient DF277, who was homozygous for the IVS2 + 2 T>C splice donor mutation, expressed scant levels of SBDS protein. Patient SD101 expressed low levels of SBDS protein harboring an R169C missense mutation. Patient DF269, who carried no detectable gene mutations, expressed wild-type levels of SBDS protein to add further support to the growing body of evidence for additional gene(s) that might contribute to the pathogenesis of the disease phenotype. The SBDS protein was detected in both the nucleus and the cytoplasm of normal control fibroblasts, but was particularly concentrated within the nucleolus. SBDS localization was cell-cycle dependent, with nucleolar localization during G1 and G2 and diffuse nuclear localization during S phase. SBDS nucleolar localization was intact in SD101 and DF269. The intranucleolar localization of SBDS provides further supportive evidence for its postulated role in rRNA processing.

Infections in patients with Shwachman-Diamond syndrome

Shwachman-Diamond syndrome (OMIM 260400) is a multisystemic disorder characterized by pancreatic insufficiency, bone marrow dysfunction, skeletal abnormalities and immune dysfunction. Prompted by the case of a 13-year-old girl with Shwachman-Diamond syndrome who presented with pneumonia attributable to Pseudomonas aeruginosa, we review infectious complications of this disease. Pneumonia, recurrent otitis media and skin infections/abscesses constitute the majority of infections among these children.

Congenital aplastic anemia caused by mutations in the SBDS gene: a rare presentation of Shwachman-Diamond syndrome

CLINICAL FINDINGS

Aplastic anemia was diagnosed at birth for a first child from healthy nonconsanguineous parents. The girl had hypoglycemia, which normalized within 2 months. Cow milk allergy was suspected initially, because of skin lesions and diarrhea, followed by severe growth retardation. Clinical and radiologic symptoms gradually became typical for Shwachman-Diamond syndrome. Two common mutations in the SBDS gene (183-184TA-->CT [K62X] and IVS2(258)+2T--> C [C84fs]) were found.

RESULTS

Bone marrow transplantation from a matched unrelated donor was unsuccessful. The genetic information from the deceased patient enabled us to perform prenatal molecular studies during the subsequent pregnancy, successfully predicting a nonaffected child.

CONCLUSIONS

This report describes for the first time the hematologic abnormalities of congenital aplastic anemia and prolonged neonatal hypoglycemia as the presenting symptoms of Shwachman-Diamond syndrome. The finding of common mutations in the presence of these symptoms at birth suggests the lack of a clear phenotype-genotype relationship in this syndrome.

Successful unrelated donor bone marrow transplantation for Shwachman-Diamond syndrome with leukemia

Shwachman-Diamond syndrome (SDS) is a rare congenital disorder featuring exocrine pancreatic insufficiency, growth retardation, and bone marrow dysfunction. Reports suggest that nearly 25% of all cases are complicated with leukemia. Although stem cell transplantation is the sole option for these patients, successful results are rarely obtained. Poor outcomes are often related to graft failure and cardiac and other organ toxicities. We describe in this report successful unrelated donor bone marrow transplantation for a patient with SDS who progressed to acute myelogenous leukemia. The patient received attenuated intensified chemotherapy because of his intolerance to ordinary chemotherapy and went into remission. Sustained unrelated donor bone marrow engraftment was accomplished after treatment with a reduced amount of cyclophosphamide and antithymocyte globulin with 12 Gy of total body irradiation as a conditioning regimen. To the best of our knowledge, this report is the first to describe unrelated donor bone marrow transplantation with complete engraftment for an SDS patient with myelogenous leukemia.