VACTERL-H Association and Fanconi Anemia.

Patients with Fanconi anemia (FA) often have birth defects that suggest the diagnosis of VATER association. A review of 2,245 cases of FA reported in the literature from 1927 to 2012 identified 108 cases with at least 3 of the defining features of VATER association; only 29 had been so noted by the authors. The FA VATER signature was the significantly higher frequency of renal and limb (radial and/or thumb) anomalies (93% of cases had both) compared with less than 30% of VATER patients; the presence of one or both of these birth defects should lead to testing for FA. The relative frequencies of the genotypes of the patients with FA VATER were strikingly different from those expected from the general FA population; only 19% were FANCA, while 21% were FANCB, 14% FANCD1/BRCA2, and 12% FANCD2. Consistent with their genotypes, those with the FA VATER phenotype had a worse prognosis than FA patients with milder phenotypes, with shorter median survival and earlier onset of malignancies. The early identification of FA patients among infants with VATER association should lead to earlier more proactive management, such as cancer surveillance and genetic counseling.

Disease-specific hematopoietic cell transplantation: nonmyeloablative conditioning regimen for dyskeratosis congenita.

Dyskeratosis congenita (DC) is characterized by reticular skin pigmentation, oral leukoplakia and abnormal nails. Patients with DC have very short telomeres and approximately one-half have mutations in telomere biology genes. A majority of patients with DC develop BM failure (BMF). Hematopoietic cell transplantation (HCT) represents the only known cure for BMF in DC, but poses significant toxicities. We report six patients who underwent allogeneic HCT with a novel nonmyeloablative conditioning regimen specifically designed for DC patients. Graft sources included related PBSCs (1), unrelated BM (2) and unrelated double umbilical cord blood (3). Complete donor engraftment was achieved in five of six patients. One patient had initial autologous hematopoietic recovery, which was followed by a second transplant that resulted in 88% donor chimerism. With a median follow-up of 26.5 months, four patients are alive, three of whom were recipients of unrelated grafts. We conclude with this small study that encouraging short-term survival can be achieved with HCT in patients with DC using a preparative regimen designed to promote donor engraftment and minimize life-threatening disease-specific complications such as pulmonary fibrosis. Long-term follow-up will be crucial with respect to individualized patient care with each of the transplanted individuals.

Oral and dental phenotype of dyskeratosis congenita.

Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome that is characterized by lacey reticular hyperpigmentation of the skin, dystrophic nails, mucous membrane leukoplakia and pancytopenia. Diagnosis may be delayed until clinical signs are apparent. Severe pancytopenia frequently causes early mortality of DC patients, who have an increased risk of developing oropharyngeal squamous cell carcinoma. Several case reports have described oral changes in DC, which include oral leukoplakia, increased dental caries, hypodontia, thin enamel structure, aggressive periodontitis, intraoral brown pigmentation, tooth loss, taurodontism and blunted roots. We determined the prevalence of these previously reported findings in a cohort of 17 patients with DC and 23 family members. The most common oral changes in DC patients were oral leukoplakia (65% of the entire DC population), decreased root/crown ratio (75% with sufficient tooth development) and mild taurodontism (57% with sufficient tooth development). From the clinical perspective, a diagnosis of DC or other inherited bone marrow failure syndrome should be considered in young persons with oral leukoplakia, particularly those with no history of smoking. Multiple permanent teeth with decreased root/crown ratios further suggest DC.

Comparative genome analysis delimits a chromosomal domain and identifies key regulatory elements in the alpha globin cluster.

We have cloned, sequenced and annotated segments of DNA spanning the mouse, chicken and pufferfish alpha globin gene clusters and compared them with the corresponding region in man. This has defined a small segment ( approximately 135-155 kb) of synteny and conserved gene order, which may contain all of the elements required to fully regulate alpha globin gene expression from its natural chromosomal environment. Comparing human and mouse sequences using previously described methods failed to identify the known regulatory elements. However, refining these methods by ranking identity scores of non-coding sequences, we found conserved sequences including the previously characterized alpha globin major regulatory element. In chicken and pufferfish, regions that may correspond to this element were found by analysing the distribution of transcription factor binding sites. Regions identified in this way act as strong enhancer elements in expression assays. In addition to delimiting the alpha globin chromosomal domain, this study has enabled us to develop a more sensitive and accurate routine for identifying regulatory elements in the human genome.

Griscelli syndrome: rare neonatal syndrome of recurrent hemophagocytosis.

Griscelli syndrome (GS) is a rare inherited disease characterized by immunodeficiency and partial albinism. The microscopic findings of the skin and hair are highly suggestive of the disease. The GS locus colocalizes on chromosome 15q21 with the myosin-Va gene (MYO5a), and mutations have been identified in few patients. We describe a 2-month-old Hispanic girl with severe pancytopenia secondary to hemophagocytosis. Even though a mutation at the Griscelli locus had not been identified, her clinical features and outcome were typical of GS. The purpose of this article is to alert physicians to the association between GS and hemophagocytosis. We suggest that GS should be considered in infants with hemophagocytosis because the features of partial albinism can be subtle. The relevant literature is summarized.

Successful bone marrow transplantation in a patient with Schimke immuno-osseous dysplasia.

Early death in Schimke immuno-osseous dysplasia often results from renal failure and/or cell-mediated immunodeficiency. Kidney transplants have improved renal function, but effective therapy for the immunodeficiency has not yet been reported. We describe markedly improved marrow function 2 years after bone marrow transplantation in a boy with Schimke immunoosseous dysplasia.

Fanconi anemia: myelodysplasia as a predictor of outcome.

The adverse potential of the development of myelodysplastic syndrome (MDS) in Fanconi anemia (FA) was examined in a retrospective study of 41 FA patients who had bone marrow morphology and chromosomes reviewed by a single group. Thirty-three patients had adequate cytogenetic studies, and 16 (48%) had one or more abnormal studies: nine initially, and seven more on follow-up. Cytogenetic clonal variation was frequent, including disappearance of clones, clonal evolution, and appearance of new clones. The estimated five-year survival with a cytogenetic clone is 0.40, compared to 0.94 without a clone. Morphologic myelodysplasia (MDS), independent of a cytogenetic clone, was found in 13/41 patients (32%). The estimated five-year survival with MDS is 0.09, versus 0.92 without MDS. Leukemia developed in three patients whose initial cytogenetic clones prior to leukemia were t(1;18), t(5;22) and monosomy 7; the one with t(1;18) also had MDS. Our results focus on marrow morphology, and suggest that morphologic MDS may be more important than classical cytogenetics in prediction of an adverse outcome.

Pregnancy in bone marrow failure syndromes: Diamond-Blackfan anaemia and Shwachman-Diamond syndrome.

Pregnancy in bone marrow failure syndromes has risk to mother and fetus. There are fewer than 30 reports of cases with Diamond-Blackfan anaemia (DBA), and none with Shwachman-Diamond syndrome (SD). We report two DBA and one SD cases. One DBA mother received transfusions intra-partum, and the other only post-partum. Both required caesarean sections (C-sections) for failure of labour to progress and severe pre-eclampsia respectively. Both subsequently resumed pre-pregnancy steroid-induced control of anaemia. approximately 40% of DBA pregnancies required maternal transfusions; 25% delivered by C-section. The SD patient also had Ehlers-Danlos (ED) syndrome and urticaria pigmentosa (UP). Her blood counts were adequate until week 38, when the platelet count dropped and a C-section was performed. Pregnancy management in marrow failure disorders requires obstetricians with expertise in high-risk pregnancies, and haematologists with experience with marrow failure syndromes.

Bone marrow failure syndromes.

Laboratory diagnosis of inherited bone marrow failure syndromes includes general evaluations, such as blood counts, examination of the peripheral blood smear for morphology, and bone marrow aspirates and biopsies, which may help the clinician classify the patient, particularly if there are no characteristic physical anomalies. Specific diagnoses require unique tests that are only available for a few of the diagnoses. The most useful is chromosome breakage in the diagnosis of FA, with gene mutation analysis or mapping about to become the gold standard when all of the FA genes have been cloned. The diagnosis of DC remains clinical at this time, although linkage to Xq28 and skewed maternal X inactivation may be helpful in some families. Laboratory proof of SD may be provided by decreased serum trypsinogen or other evidence of exocrine pancreatic insufficiency. CHH is substantiated when absent central pigment in hair is found and when it is mapped to 9p21-p13. The only mitochondrial syndrome, PS, is proved with demonstration of deleted mitochondrial DNA. RD is diagnosed from blood and marrow studies that demonstrate lack of lymphoid as well as myeloid activity. Amega requires absent or abnormal marrow megakaryocytes; if radii are also absent, the diagnosis is TAR. DBA usually has elevated red-cell ADA, and the DBA locus may map to 19q13. KS is diagnosed in patients who have congenital nonimmune severe neutropenia. Clinical suspicion of particular diagnoses can often be substantiated by laboratory tests of varying specificity.

Embryonic hemoglobins are expressed in definitive cells.

Human embryonic zeta and epsilon globin chains are synthesized in yolk sac-derived primitive erythroid cells, and decrease rapidly during definitive erythropoiesis. Examination of zeta and epsilon globin expression at the cellular level using dual-color immunofluorescence staining with specific monoclonal antibodies showed that embryonic globin proteins are present in definitive erythroid cells. More than half of fetal erythrocytes were positive for zeta and approximately 5% for epsilon globin. Approximately one third of newborn red blood cells were zeta-positive and less than 1% epsilon-positive. Adult erythrocytes did not have embryonic globins. Erythroblasts that developed in liquid cultures also contained embryonic globin in amounts which declined with ontogenic age, and the proportion of positive cells in vitro was less than in the comparable erythrocytes that developed in vivo. Thus, embryonic globin chains are synthesized in definitive erythroid cells and decrease with ontogeny. Modulation of embryonic globin gene expression is not solely due to a switch from primitive to definitive erythropoiesis.

Hematopoietic growth factors for the treatment of aplastic anemia.

The use of hematopoietic growth factors, although well established for the management of chemotherapy-induced neutropenia, remains controversial for the treatment of aplastic anemia and inherited bone marrow failure syndromes. The most commonly used factors are granulocyte colony-stimulating factor, granulocyte macrophage colony-stimulating factor, and erythropoietin. Newer growth factors such as stem cell factor, thrombopoietin, Flt3 ligand, and interleukins have shown promising results in the laboratory, and some have been used in clinical trials. This article reviews the clinical use of old and new hematopoietic growth factors in acquired and inherited bone marrow failure, and discusses emerging concerns about long term toxicity of these factors.

Pure red cell aplasia associated with hepatitis C infection.

We report the case of a 34-year-old woman with recurrent pure red cell aplasia and evidence of hepatitis B and C infection. Review of the English literature identified 19 prior cases in which pure red cell aplasia was associated with hepatitis. This case is the first in which serologic evidence of hepatitis C infection was documented. This patient also had porphyria cutanea tarda and marked hepatic siderosis but no active hepatitis or cirrhosis. Treatment with cyclophosphamide and prednisone produced complete remission of the pure red cell aplasia. Erythroid colony formation (colony-forming unit-erythroid and erythroid burst-forming unit) was reduced in cultures of bone marrow obtained during relapse but was normal in remission marrow. However, addition of the patient serum, whether collected during relapse or remission, inhibited erythroid colony formation by her bone marrow. These observations, and the known extrahepatic immunologic manifestations of hepatitis C infection, suggest that the pure red cell aplasia occurred because of autoimmune mechanism provoked by the infection.

Treatment of dyskeratosis congenita with granulocyte colony-stimulating factor and erythropoietin.

Aplastic anaemia is both frequent and difficult to manage in patients with dyskeratosis congenita (DC). We recently treated a 23-year-old male for a year with granulocyte colony-stimulating factor (G-CSF) and erythropoietin (Ep), with an excellent neutrophil response, and a transient effect on haemoglobin levels. G-CSF alone or combined with other cytokines may provide at least a partial effect in pancytopenic patients with DC.