Reflections
Kon-Taik Khaw, M.D., M.P.H.

Introduction
Susan Burroughs, M.D., Chairman SDSI Scientific Advisory Board

Italian Registry of Shwachman Syndrome
L. Giglio, E. Neri, P. Petaros, M. Cipolli, A. Amici, I. Mazzarino, A. Arrighini, C. Barbera, L. Brushci, C. Catassi, G. Cavaleri, N. Cimadamore, C. D’Orazio, E. Di Bona, P. Failla, D. Faraguna, P. Fusco, T. Gentile, G. Guariso, S. Varotto, S. Cesaro, C. Messina, L. Zanesco, V. Lucidi, M. Masi, A. Miano, R. Padoan, V. Poggi, G. Menna, V. Raia, P. Roggero, D. Stramare, G. Taccetti, C. Ughi, S. Valerioti, and G. Mastella, Italian Association Shwachman Syndrome

Serum Pancreatic Enzymes in Patients with Shwachman-Diamond Syndrome
W.F. Ip, L. Ellis, S. Beharry, J. Morrison, J. Rommens, and P.R. Durie

Is there a Generalized Defect of Acinar Cell Development in Shwachman-Diamond Syndrome
M. Stormon, W. Ip, J. Rommens, L. Ellis, M. Freedman, and P. Durie
Hematopoietic Stem Cell Transplantation in Patients with Shwachman-Diamond Syndrome
A. Vlachos
Bone Marrow Failure in Shwachman-Diamond Syndrome
B. Alter

Meeting of SDSI Scientific Advisory Board

Shwachman-Diamond Syndrome (SDS) is the second most common cause of inherited/congenital pancreatic insufficiency after cystic fibrosis. The main associated features are cyclic neutropenia, metaphyseal dysostosis, and growth retardation. Other organs or functions may be involved, with a wide range of abnormalities and symptoms. We report on the pathomorphosis and follow-up of 18 patients (11 male, 7 female) with SDS admitted to our department, focusing on modification of the exocrine pancreatic function over time. The age at diagnosis was 12.1 months (range 4–26 months). Nine of these patients were included in long-term follow-up evaluation, mean age 8.4 years (range 2.2–13.3 years). One patient died at 6 months of age due to respiratory problems. At diagnosis, growth retardation was present in all patients and all subjects showed pancreatic insufficiency. Hematological features [intermittent neutropenia (83%, severe 39%), anemia (39%) and thrombocytopenia (17%)], respiratory infection during the first years of life, and skeletal abnormalities (100%, most commonly short ribs and/or metaphyseal dyschondroplasia) were also frequently observed. Other associated features at diagnosis included hepatic involvement (elevated ALT and AST, hepatomegaly) and occasional renal dysfunction. In the nine patients with follow-up, a significant growth improvement was observed. In seven of them the pancreatic stimulation test showed values of lipase within reference range, whereas fat balance or fecal fat losses were normal in all but one subject. Such patients were able to cease pancreatic enzyme therapy. The mean age was 9.5 years (range 6–15 years). Among seven subjects assessed by psychological evaluation, IQ test results were markedly abnormal in one and bordered on abnormality in the others. Two patients developed severe neutropenia and are being treated with human granulocyte colony stimulating factor. Two had acute lymphoblastic leukemia and one underwent bone marrow transplantation. One patient developed myelodysplastic syndrome.

In conclusion, the present data underline the possibility of improvement or normalization of exocrine pancreatic function with age, suggesting the need for periodic checks on pancreatic activity in SDS patients. It also indicates the possible diagnosis of this syndrome in the absence of pancreatic insufficiency, the decreasing frequency of infections over time, and the usefulness of early neuropsychological evaluation. Neutropenia, skeletal abnormalities, and psychological conditions do not appear to improve with time. The frequency of MDS and leukemia are difficult to establish.

This presentation was followed by an abstract entitled Genetic Mapping Studies in Shwachman-Diamond Syndrome, presented by Johanna M. Rommens, Ph.D., Associate Professor, University of Toronto, Senior Scientist, Program in Genetics and Genomic Biology, Hospital for Sick Children, Toronto, Ontario, Canada. Co-authors included S.L. Goobie, M. Popovic, J. Morrison, L. Ellis, G. Boocock, N. Ehtesham, H. Ginzberg, T.J. Hudson, T.M. Fujiwara, K. Morgan, and P.R. Durie.

Summary of Research:
Shwachman-Diamond syndrome (MIM260400) is inherited in an autosomal-recessive manner as determined by segregation analysis. Our collection presently consists of 200 families, 16 of which have two or more affected children. Two families reported consanguinity. Approximately 160 patients adhere to strict diagnostic criteria of hematological abnormalities and exocrine pancreatic dysfunction. In order to identify the genetic defect, a genome-wide scan has been carried out with families with two or three affected children using micro satellite markers from a modified version of the CHLC Human Screening Set, Version 6.0. Densely spaced markers are being used to validate the regions that showed suggestive evidence of linkage. Two-point lod scores are being calculated using the FASTLINK 3.OP software of the LINKAGE 5.1 Program under the assumptions of recessive inheritance, complete penetrance, equal allele frequencies, and a disease frequency of 1/50,000. Chromosomes 1, 3, and 7 had interesting markers, with chromosome 7 appearing the most promising. The lod score from an area on chromosome 7 near the centromere indicates a critical interval containing the affected locus. The marker make-up between affected individuals appears quite different on a preliminary evaluation, suggesting that there may be different mutations in the gene in different families. The location near the centromere and the lack of known genomic sequence in this region complicate further definition, but several approaches are being used to further define the area of interest.

The next section of presentations included two poster sessions. Marco Cipolli, M.D., presented on the Italian Registry of Shwachman Syndrome.

Italian Registry of Shwachman Syndrome

Giglio L, Neri E, Petaros P (Trieste); Cipolli M (Verona); Amici A, Mazzarino I (Perugia); Arrighini A (Brescia); Barbera C (Torino); Bruschi L (Pavia); Catassi C (Ancona); Cavaleri G (Caltanisetta); Cimadamore N (Ivrea); D'Orazio C (Verona); Di Bona E (Vicenza); Failla P (Troina); Faraguna D (Gorizia); Fusco P (Savigliano); Gentile T (L'Aquila); Guariso G, Varotto S, Cesaro S, Messina C, Zanesco L (Padova); Lucidi V (Roma); Masi M (Bologna); Miano A (Cesena); Padoan R (Milano); Poggi V, Menna G (Napoli); Raia V (Napoli); Roggero P (Milano); Stramare D (Pordenone); Taccetti G (Firenze); Ughi C (Pisa); Valerioti S (S. Giorgio Morgeto) and Mastella G (Verona). Italian Association Shwachman Syndrome (AISS)

Aim of the study
The goals of this study were to identify all patients with SDS known in Italy and to create a National Registry, to study all the features of the syndrome in a large cohort of patients, and to identify the best standard diagnostic and therapeutic strategies. We contacted cystic fibrosis centers, pediatric gastroenterologists, hematologists, and oncologists, and clinical data of the patients were collected by a questionnaire.

Results
At present, clinical records of 47 patients with SDS have been reviewed. Of these, 42 have current follow-up, while 4 patients died at a mean age of 12.7 months, and 1 case has been lost to follow-up. The median age at diagnosis was 11 months (range: 16 days–14 years).

The pancreatic dysfunction was diagnosed in 45 of 47 cases. Two patients who were diagnosed at relatively late ages did not have evidence of current pancreatic dysfunction. It is known that pancreatic function significantly improves with age and this is probably the case in our two patients. Hematologic abnormalities were present in 45 of 47 cases; of these cases, 43 had persistent or intermittent neutropenia (in 9 cases not associated with other marrow dysfunctions), 1 had anemia associated with impaired chemotaxis, and 1 had thrombocytopenia. The absence of hematological abnormalities in 2 cases may be due to the intermittent nature of the neutropenia. Of the other clinical manifestations usually associated with SDS, short stature was the most frequent feature described in our patients at the time of diagnosis (93% of cases), followed by recurrent infections (69.8%) and skeletal abnormalities (69.6%). The median age of the patients at the last visit is 11.7 years; the oldest patient is now 29 years old. The pancreatic function showed improvement with increasing age, and after the age of 4, 39.5% of patients discontinued the pancreatic enzyme replacement therapy. Acute myeloid leukemia developed in one case at age 17 and acute lymphoblastic leukemia in another case at age 2.7. Nine patients were treated with G-CSF. We are working to plan other strategies to identify more patients with SDS. The diagnosis of SDS may be difficult because of the wide spectrum of disease phenotype and we are aware that a lot of cases are still missing.

Linda Ellis presented a poster on Serum Pancreatic Enzymes in Patients with Shwachman-Diamond Syndrome, co-authored by WF Ip, S Beharry, J Morrison, J Rommens, and PR Durie of the Research Institute, Hospital for Sick Children, University of Toronto, Ontario, Canada.

Serum trypsinogen is a useful index of pancreatic status in SDS patients in that those who develop pancreatic sufficiency with age have values >6µg/L. The poster evaluated the use of isoamylase as another marker of pancreatic dysfunction in SDS. In 123 healthy controls, (age 0.33–0.55 yrs), serum trypsinogen values were within reference range (16.9–46.5 µg/L) in all age groups. Serum isoamylase values were low in the first two years of life (range 1–29U/L), then increased to adult values (range 17–80U/L). In the 86 SDS patients who were diagnosed by evidence of pancreatic and hematologic dysfunction, serum isoamylase activities were uniformly low at all ages, regardless of whether they had been categorized as pancreatic sufficient or insufficient. The persisting low isoamylase level indicated that the SDS exocrine pancreas remains functionally compromised at all ages. We also evaluated 64 patients with a suspected diagnosis of SDS. Serum trypsinogen values were in the pancreatic sufficient range, but approximately 50% had low isoamylase values (<17U/L). These results suggest that after 2 years of age, serum isoamylase may be useful as an adjunctive diagnostic test of SDS.

The next session was entitled Hematology of Shwachman-Diamond Syndrome. Blanche Alter, M.D., M.P.H., Visiting Professor of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD, and Cancer Expert in Cancer Epidemiology and Genetics Division, Clinical Genetics Branch, National Cancer Institute was co-chairman of the session together with Susan F. Burroughs, M.D.

The first presentation of this session was by Frederick Goldman, M.D., and was co-authored by D. Shutt and D. Soll. Dr. Goldman is an Associate Professor, Pediatric Hematology/Oncology/Interim Director, Bone Marrow Transplantation, University of Iowa Hospital and Clinics, Iowa City, Iowa.

Defective Leukocyte Motility as a Diagnostic Tool for Shwachman-Diamond Syndrome

Details from this study revealed that patients with subtle clinical features of Shwachman-Diamond Syndrome may be able to be diagnosed at an earlier age with a new laboratory technique that looks at leukocyte motility. Using a very sophisticated computer assisted motion analysis system (DIAS), we were able to detect significant differences in both the quality and quantity of motile responses in leukocytes from two patients, thus confirming their SDS diagnosis. In addition, these studies may have an additional benefit in being able to identify the defective gene in SDS. Our data suggest that the defective gene likely encodes a cytoskeletal protein, an adhesion protein, or some signal transduction component that modulates cytoskeletal assembly.

Blanche Alter, M.D., gave a presentation entitled Hematologic Aspects of Shwachman-Diamond Syndrome.

The SDS literature was reviewed and included case summaries of >325 SDS patients. The male to female ratio was 1.7:1. Thirty percent had metaphyseal dysostosis (MD), 38% aplastic anemia (AA), 6% leukemia, 5% myelodysplastic syndrome (MDS), and 19% were deceased. An unexpected finding was that the leukemia patients were predominantly male (16 male, 1 female, 1 not stated). Life table analyses were done using AA, leukemia, and MDS as the exclusive end points, censoring each for all other outcomes. The cumulative probability of AA was ~80%, with 50% by age 20. The probability of leukemia was ~100%, with 50% at age ~38 years. MDS plateaued at 15% by age 15 years. Risk factors from simple linear regression or Cox proportional hazards were: AA, female without MD; MDS, no MD; leukemia, male. G-CSF treatment is effective for neutropenia in SDS, although there may be a risk for clonal cytogenetic abnormalities such as monosomy 7. The reported leukemias were primarily acute myeloid, although there were 5 acute lymphoblastic leukemias. There were 17 bone marrow transplants (BMT) in the literature, 7 from HLA-matched siblings and 10 from parents or unrelated donors; indications were AA in 3, leukemia in 6, and MDS in 8. Absolute survivals were 4/7 sib donors and 5/10 unrelated or mismatched. The median probability of survival was at ~400 days, with overall survival plateaus at ~35%. The highest proportional death rates were in those with leukemia. The recommendation is that SDS patients have a complete blood count every 4 months or more often as needed and that an annual bone marrow be done to monitor for MDS or early leukemia, with an aspirate for morphology, special stains, and cytogenetics as well as a biopsy for cellularity. These specimens can also be used for research (see Research in Cancer-prone Rare Genetic Syndromes).

The next two presentations were given by Melvin H. Freedman, M.D., Professor, Department of Pediatrics, University of Toronto, Division on Hematology, The Hospital for Sick Children, Toronto, Ontario, Canada.

Inherited Marrow Failure and Malignant Hematopoietic Transformation

Historically, the inherited marrow failure syndromes were classified as "benign" hematology, which contrasted sharply with the malignant myeloid disorders. Patients with Kostmann's syndrome/congenital neutropenia, Shwachman-Diamond syndrome, Fanconi's anemia, congenital amegakaryocytic thrombocytopenia, and Diamond-Blackfan anemia often died early in life from complications of their respective disorders. However, in the current era of advanced supportive care and availability of recombinant cytokines and other effective therapeutics, patients with these conditions usually survive the early years and beyond. With the extended lifespan of patients, a new natural history for some of these disorders is evident. One of the most sobering observations is that most of these "benign" disorders confer an inordinately high predisposition to MDS/AML. For instance, the actuarial probability of developing MDS/AML in a Fanconi's anemia patient who lives to be 30 years of age is 50%. In SDS, the incidence appears to be 8–33%. Because of the early deaths of most congenital neutropenia patients prior to the current era, no good figures on the risk of transformation are available. Thus, the distinction between "benign" and "malignant" hematology in the context of the inherited marrow failure disorders has become blurred, and a new clinical and hematological continuum is evident. With respect to the inherited neutropenias, G-CSF therapy has complicated the issue. Patients with congenital neutropenia began to be treated with G-CSF in clinical trials in 1987 and after its release in 1994 and were followed in a registry. Approximately 95% of patients have responded with absolute neutrophil counts in the normal range. Currently, 9% of these patients taking G-CSF have transformed to MDS/AML. The role, if any, of G-CSF in the transformation is becoming clearer as various risk factors are analyzed. Most patients with congenital neutropenia who transform acquire the loss of either all or part of the long arm of chromosome 7, a finding typically seen with de novo idiopathic malignancy, secondary disorders (especially toxin related), and inherited marrow failure syndromes. Trisomy 21 can also be seen. Patients may also develop acquired RAS mutations in codon 12 (approximately 50% of transforming patients) or a mutation of the G-CSF receptor gene (26%).

Patient demographics and G-CSF dosing do not appear to be different between the patients receiving G-CSF who transformed and those who did not. The hazard rate has varied with duration of administration, between 1.2% and 9.5%. There does not appear to a linear relationship between years of G-CSF use and malignant transformation. Thus, the role of G-CSF in transformation is unclear, either unmasking an underlying predisposition, accelerating a predisposition, or, less likely, causing malignancy. Information gleaned from yearly bone marrow biopsies and aspirates has shown that the cluster to colony ratio in a clonogenic assay is completely reversed in myelodysplasia in adults. Hemoglobin F levels were at the highest level in three patients with cytogenetic clonal abnormalities. Some patients will have an abnormal cytogenetic marker such as isochromosome 7. However, the significance of these abnormalities is not known and they have been shown to revert in some cases, without the development of MDS/AML.

Dr. Freedman then presented a paper co-authored by Dr. Dror.

The Hematopoietic Stem Cell Defect in Shwachman-Diamond Syndrome and the Role of Apoptosis in the Pathogenesis of Marrow Failure

Yigal Dror, M.D., Melvin H. Freedman, M.D., F.R.C.P.(C)

Department of Pediatric Hematology/Oncology, The Chaim Sheba Medical Center, Tel-Hashomer, Israel and Department of Pediatrics, Division of Hematology and Oncology, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.

Summary of Research

Background
Shwachman-Diamond syndrome (SDS) is an inherited bone marrow failure disorder with varying cytopenias and a strong predilection to myelodysplastic syndrome (MDS) and acute myeloid leukemia. Previously, we found that the percentage of CD34+ cells in bone marrows and the in vitro colony formation from CD34+ cells of SDS patients were markedly reduced, indicating faulty progenitor cells that don't proliferate properly. A stromal cell defect in the marrow supporting structure is abnormal in its support of hematopoiesis. Apoptosis is central in the pathogenesis of bone marrow dysfunction in MDS. This study was initiated to delineate the role of apoptosis in the pathogenesis of the marrow failure.

Methods
Eleven children with SDS were studied. The propensity of marrow progenitors to undergo apoptosis when cultured in clonogenic assays and the effect of activating anti-fas antibody on the rate of apoptosis and colony formation were investigated. Fas expression on various marrow cell subpopulations was also investigated by flow cytometry.

Results
Compared to normal controls, patients' marrow mononuclear cells plated in clonogenic cultures showed a significantly higher tendency to undergo apoptosis. The defect in SDS was found in patients with and without MDS. Patients showed a more prominent decrease in colony formation and increased apoptosis after pre-incubation with activating anti-fas antibody. Fas expression on marrow cells from patients was significantly higher than normal controls. The difference between patients and controls for fas expression was also significant for the following subpopulations: CD34-/CD38-, CD34-/CD38+, and CD34+ cell fractions.

Conclusions
SDS hematopoietic progenitors are intrinsically flawed with faulty proliferative properties and increased apoptosis. Bone marrow failure in SDS appears mediated by increased apoptosis as the central pathogenetic mechanism. This increased propensity for apoptosis is linked to increased expression of the fas antigen and hyperactivation of the fas signaling pathway. Future therapeutic strategies aiming at suppressing programmed cell death and fas expression may prove effective in treating Shwachman-Diamond syndrome patients with cytopenia and myelodysplasia without excess blasts.

The third session was entitled Bone Marrow Transplant in Shwachman-Diamond Syndrome and was chaired by Adrianna Vlachos, M.D., Associate Professor of Pediatrics, Albert Einstein School of Medicine, New Hyde Park, NY. The first presentation was given by Laura Worth, M.D., Ph.D., Clinical Instructor, Division of Bone Marrow Transplant, Department of Pediatrics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.

Fludarabine-based Preparative Regimen for Matched Unrelated Bone Marrow Transplant in a 5-year-old with SDS

Laura L. Worth, M.D., Ph.D., and Ka Wah Chan, M.D.
University of Texas M.D. Anderson Cancer Center

Summary of Research: Patients with Shwachman-Diamond syndrome have bone marrow dysfunction with an increased frequency of myelodysplasia and leukemic transformation. Allogeneic bone marrow transplant is being used more frequently as a curative treatment for these conditions. The literature suggests a poor outcome after allogeneic transplant: Patients with SDS have an abnormal marrow microenvironment and because of underlying organ dysfunction have an increase of transplant-associated problems.

We report a 5-year-old with SDS and aplastic anemia unresponsive to steroids, cyclosporine, and anti-thymocyte globulin treatment. Because of her young age we chose a non-irradiation-based preparative regimen. Fludarabine-based preparative regimens have been used in unrelated donor transplants for Fanconi's anemia with success. Consequently, we chose a preparative regimen consisting of cyclophosphamide (60 mg/kg/d x 4), fludarabine (30 mg/m2/d x 4), and anti-thymocyte globulin (30 mg/kg/d x 3). The patient had evidence of bone marrow engraftment as evidenced by an absolute neutrophil count of > 500/ul by day 22. She was red blood cell and platelet independent by days 25 and 51 respectively. The post-transplant period was complicated by tacrolimus-induced altered mental status changes and seizures, pulmonary hemorrhage, stroke, and acute and subsequent chronic Graft-versus-Host Disease of the liver and skin. Eleven months after transplant, the patient died from complications associated with Graft-versus-Host Disease and its therapies. Patients with SDS can be treated with allogeneic BMT using non-irradiation-based preparative regimens but have increased rates of transplant-related problems, some of which may be host related.

Dr. Goldman was the presenter for the second abstract in this session.

Successful Hematopoietic Stem Cell Transplantation (HCST) for Shwachman-Diamond Syndrome Using a Cardiotoxic-sparing Myeloablative Regimen

Details from this study indicate that bone marrow transplantation can be successful in patients with SDS if attention is paid to the type of myeloablative therapy used. Additionally, both patients were transplanted at a young age (1 and 2.5 years), suggesting better outcome may be achieved by early BMT prior to the onset of organ dysfunction. Specifically, our myeloablative regimen utililized Melphalan (60 mg/m2 x 3 days), etoposide (400 mg/m2 x 3 days), and ATG (30 mg/kg x 3 days). One patient successfully treated with this regimen had a perfectly matched sibling donor. It is of note that her case was complicated by finding mild cardiac dysfunction prior to the transplant, and this was the impetus to delete cytoxan from the preparative regimen. The other patient treated did not have a matched sibling donor, and thus we used a closely matched umbilical cord unit as a source of stem cells. Both patients had excellent and sustained engraftment and are currently doing well 1.5 to 3 years post BMT.

The program concluded with a research forum and discussion. The first research proposal was discussed by Michael Storman, M.D., Research Fellow, Division of Gastroenterology and Nutrition, Hospital for Sick Children, Toronto, Ontario, Canada.

Is There a Generalized Defect of Acinar Cell Development in Shwachman-Diamond Syndrome?

Authors: Michael Stormon, Wan Ip, Johanna Rommens, Lynda Ellis, Melvin Freedman, Peter Durie

Institution: Hospital for Sick Children, Toronto, Canada

Summary of Proposed Research

Shwachman-Diamond syndrome (SDS) is a multi-organ disease that is uncommon, has variable phenotypic features, and is difficult to diagnose. There is no reliable biochemical or genetic diagnostic test for SDS, and currently the diagnosis requires evidence of pancreatic and bone marrow dysfunction. Assessment of the exocrine pancreas is problematic. The only reliable investigation is the direct pancreatic stimulation test, which is invasive, impractical, and not routinely performed.

Less-invasive tests of pancreatic dysfunction, such as serum cationic trypsinogen, accurately reflect pancreatic acinar function in SDS and identify patients who are pancreatic insufficient (PI). However, in SDS patients who become pancreatic sufficient (PS) trypsinogen levels rise with age and may become normal. Thus, serum trypsinogen is not a reliable diagnostic test of pancreatic dysfunction in SDS. It has been previously shown on pancreatic stimulation testing that all patients with SDS, including those who are PS, have pancreatic dysfunction.

Our preliminary studies suggest that serum pancreatic isoamylase is a reliable marker of acinar cell dysfunction in SDS. An international cohort of 86 patients (50 PI, 36 PS) had uniformly low pancreatic isoamylase levels, regardless of their age or pancreatic function status. Furthermore, total amylase levels were low, suggesting that acinar cells in the parotid gland (which synthesize and secrete alpha amylase) may also be affected in SDS.

Some patients with SDS and PS have recurrent symptoms suggestive of carbohydrate malabsorption (crampy abdominal pain, bloating, excessive flatus, and diarrhea), which could be explained by low levels of pancreatic and salivary amylase.

Demonstration of deficient secretion of salivary enzymes would provide evidence of a generalized disorder of acinar cell function in SDS. This could lead to a more specific and accessible marker of the syndrome.

We plan to conduct a pilot study to determine whether SDS is characterized by a generalized disorder of acinar cell function.

The objectives are:

1. To evaluate pancreatic and salivary acinar cell function through the measurement of serum acinar cell enzyme concentrations (pancreatic amylase and lipase, trypsinogen, salivary amylase)
2. To evaluate acinar cell function of the parotid gland by collecting and analyzing parotid saliva for amylase, protein, and electrolyte composition

A presentation on proposed research in hematopoietic stem cell transplantation in patients with Shwachman-Diamond syndrome was given by Adrianna Vlachos, M.D. She reviewed the history of bone marrow transplantation in SDS patients beginning in 1989. Seventeen patients have been reported, six with HLA-identical siblings, one from a mismatched mother, and seven from unrelated donors. Three of the patients had pancytopenia/aplastic anemia, one had myelofibrosis, five had MDS, and five had acute leukemia. A variety of preparative regimens were used. Three of the patients with sibling donors were alive and well at the time that they were reported in the literature. The patients who received the maternal transplant died, and three of the seven unrelated transplants were alive at the time of the report. Causes of death included cardiac failure (1), relapsed leukemia (2), infection due to graft failure (1), respiratory distress syndrome (1), and Graft-versus-Host Disease (3). In the experience at Mount Sinai in New York, five transplants were performed in four patients. The first patient died with cardiomyopathy. The second patient had a good response, but then her own marrow came back. She succumbed to secondary leukemia after a second transplant. A third patient had severe veno-occlusive disease, and the fourth developed acute respiratory distress syndrome. The comorbidities present in SDS, including cardiac and hepatic abnormalities, nutritional deficiencies, preexisting infections, and prior transfusion history, complicate the transplant process.

Standard cytoreductive therapy has the goals of myeloablation to allow room for the donor marrow and immunosuppression to allow for graft acceptance. More recently, noncytoreductive stem-cell transplants have been performed that use immunoablation to ablate the defective bone marrow. A preparative regimen proposed consisted of fludarabine, ATG, and low-dose busulfan. Other important considerations were matched sibling donors when possible from an unaffected sibling, an unrelated graft from a person that is molecularly matched, and an extensive pretransplant work-up (cardiac, pulmonary, and hepatic) to allow for tailoring of the approach.

Blanche Alter, M.D., spoke about proposed research in bone marrow failure in Shwachman-Diamond syndrome.

Research in Cancer-prone Rare Genetic Syndromes
Blanche P. Alter and M. Tarek Elghetany

SDS patients are at risk for myelodysplastic syndrome (MDS) and/or leukemia. Monitoring for these complications should include an annual bone marrow examination with an aspirate for morphology, special stains, and cytogenetics as well as a biopsy for cellularity. Criteria for MDS should be objective: major = overt dysplasia including 2 or more lineages with >20% dysplasia or clonal cytogenetics involving at least 2 cells; intermediate = suggestive dysplasia involving 1 lineage; minor = myeloperoxidase deficiency, dual esterase positive, PAS-positive erythroblasts, or ring sideroblasts. Diagnosis of MDS requires 1 major, or 1 intermediate and 1 minor. Additional studies include flow cytometry for surface marker abnormalities and aberrant expression of oncogenes. A pilot study at UTMB included samples from 12 SDS patients. One had morphologic MDS and 2 probable MDS. Two were PAS positive, 1 dual esterase positive, 2 had abnormal flow cytometry, and 2 of 5 showed activation of p53. Further studies are important to determine the specific markers for MDS in SDS and to ascertain whether MDS in any form is in fact "preleukemic" in SDS.

Epidemiologic studies must be done in SDS, with identification of current SDS patients, descriptive statistics regarding prevalence and incidence of leukemia or other malignancies, specific risk factors from case-control studies, and heterozygote surveillance for cancer predisposition. The tumor tissues (bone marrow) need to be examined to learn whether markers for MDS or leukemia are the same in SDS as in other contexts. The role of screening and prevention must be identified.

Thus, the conference contained reports on the development of a consensus statement, reviews of SDS cases, and information on the Italian Registry. Advances in genetic mapping in SDS were discussed. The use of pancreatic enzymes other than trypsinogen as markers of the disorder and pancreatic sufficiency status was evaluated and also presented as an area of proposed research. Hematologic aspects addressed included defective leukocyte motility, the development and pathogenesis of bone marrow failure and malignant transformation, and bone marrow transplant experience in this disorder. The meeting offered a productive opportunity for sharing information on this disorder between clinicians and researchers from a variety of disciplines.

The First Annual Shwachman-Diamond Syndrome International (SDSI) Scientific Meeting was held on August 4, 2000, in Boston, MA. This meeting marked the first effort by SDSI to have both clinicians and researchers meet to discuss SDS. Participants attended from three different countries: Canada, Italy, and the United States. The conference reviewed the past with remarks from Kon-Taik Khaw, M.D., Professor Emeritus at Harvard Medical School, one of the co-authors of the first article on SDS. One of the goals of the conference was to look to the future, with SDSI catalyzing the interactions in a small gathering in hopes of generating broad, global interest in SDS research in the future.

The first session of the conference was an overview of SDS co-chaired by Peter Durie, M.D., Professor of the Department of Pediatrics at the University of Toronto, Department of Gastroenterology and Nutrition, the Hospital for Sick Children, Toronto, Ontario, Canada, and Susan F. Burroughs, M.D., Clinical Assistant Professor in Adult Hematology/Oncology, University of Connecticut Health Center, Farmington, CT, and Chairman of the Scientific Advisory Board of SDSI. The session began with an update on the consensus statement being developed from the Consensus Conference in July 1999 at the Second SDSI Conference in St. Louis, MO. Robert Rothbaum, M.D., Professor of Pediatrics, Division of Gastroenterology and Nutrition, Washington University School of Medicine, presented the update. The goal of the consensus committee was to explain defined features of the disease and identify less well delineated aspects of the disease in an attempt to establish a framework for the diagnosis of SDS and appropriate initial evaluation and long-term follow-up. The report contains a review of the clinical phenotype of SDS with the percentage of patients described with each feature, with appropriate references. Interestingly, almost all the features recognized as part of the phenotype in the year 2000 were mentioned in the first six patients described. Initial essential criteria to make the diagnosis of SDS were delineated, including pancreatic exocrine dysfunction and bone marrow dysfunction, as well as supporting criteria (skeletal abnormalities; growth retardation; short stature; liver involvement; frequent infections; and cardiac, renal, dental, and hearing problems). A diagnostic evaluation based on these criteria was proposed. Documentation of decreased pancreatic enzyme secretion can be done by one of the following criteria: (1) directly by duodenal intubation (gold standard), (2) by serum trypsinogen, or (3) by fat malabsorption without other cause and abnormal imaging of the pancreas. Bone marrow dysfunction is most commonly manifested as neutropenia, defined as less than 1,500 neutrophils per cubic millimeter demonstrated on repeat occasions. About 40% of patients are anemic and/or thrombocytopenic as well. A bone marrow biopsy and aspirate with cytogenetics at diagnosis can be utilized to document cellularity, cytopenias, and any evidence of malignant transformation. Treatment with pancreatic enzymes was recommended for patients with fat malabsorption. Long-term follow-up consisting of a yearly visit with a pediatric gastroenterologist and/or hematologist was proposed, with every 6–12 month evaluation of physical, psychological, and social development, with attention to nutrition and skeletal abnormalities. Pancreatic function testing was recommended to be performed every 1–2 years because of the propensity for pancreatic function to improve over time in some individuals. The frequency of monitoring blood counts was left flexible, depending on lability of counts. A bone marrow biopsy and aspirate with cytogenetics to evaluate for bone marrow failure syndromes may need to be repeated over time to monitor for development of such syndromes. Pressing issues include the need to develop (1) longitudinal data on bone marrow abnormalities, (2) an approach to persistent severe neutropenia, (3) an approach to short stature, and (4) a better definition of the role of bone marrow transplantation.

Ensuing discussion focused largely on the issue of how frequently bone marrow biopsies and aspirates should be recommended. Some discussants felt that information gathered from annual bone marrows might allow early detection of malignant transformation, give evidence of the tempo of the disease, and permit early intervention if needed. It would also provide more information about the basis of marrow failure and may eventually allow determinations of predictors of leukemia or myelodysplasia.