Poor outcome after hematopoietic stem cell transplantation of patients with unclassified inherited bone marrow failure syndromes.

Classification of inherited bone marrow failure syndromes (IBMFSs) according to clinical and genetic diagnoses enables proper adjustment of treatment. Unfortunately, 30% of patients enrolled in the Canadian Inherited Marrow Failure Registry (CIMFR) with features suggesting hereditability could not be classified with a specific syndromic diagnosis. We analyzed the outcome of hematopoietic stem cell transplantation (HSCT) in unclassified IBMFSs (uIBMFSs) and the factors associated with outcome. Twenty-two patients with uIBMFSs and 70 patients with classified IBMFSs underwent HSCT. Five-year overall survival of uIBMFS patients after HSCT was inferior to that of patients with classified IBMFSs (56% vs 76.5%). The outcome of patients with uIBMFS who received cord blood was significantly lower than that of patients who received other stem cell sources (14.8% vs 90.9%). Engraftment failure was higher among patients with uIBMFS who received cord blood than those who received bone marrow. None of the following factors were significantly associated with poor survival: transfusion load, transplant indication, the intensity of conditioning regimen, human leukocyte antigen-identical sibling/alternative donor. We suggest that identifying the genetic diagnosis is essential to modulate the transplant procedure including conditioning agents and stem cell sources for better outcome and the standard cord blood transplantation (CBT) should be avoided in uIBMFS.

Androgen therapy in inherited bone marrow failure syndromes: analysis from the Canadian Inherited Marrow Failure Registry.

Progressive cytopenia is a serious complication among paediatric patients with inherited bone marrow failure syndromes (IBMFS). Androgens have been used to improve blood counts in different bone marrow failure conditions. Little is known about efficacy and toxicity with new androgens (i.e., danazol) in different types of IBMFS. We identified 29 patients from the Canadian Inherited Marrow Failure Registry, who received oxymetholone or danazol. Sixteen (55%) had haematological response including patients with unclassified IBMFS (45%). Danazol showed a better toxicity profile and similar efficacy compared to oxymetholone. Androgens are an effective and safe option to ameliorate bone marrow failure in IBMFS.

Reanalysing genomic data by normalized coverage values uncovers CNVs in bone marrow failure gene panels.

Inherited bone marrow failure syndromes (IBMFSs) are genetically heterogeneous disorders with cytopenia. Many IBMFSs also feature physical malformations and an increased risk of cancer. Point mutations can be identified in about half of patients. Copy number variation (CNVs) have been reported; however, the frequency and spectrum of CNVs are unknown. Unfortunately, current genome-wide methods have major limitations since they may miss small CNVs or may have low sensitivity due to low read depths. Herein, we aimed to determine whether reanalysis of NGS panel data by normalized coverage value could identify CNVs and characterize them. To address this aim, DNA from IBMFS patients was analyzed by a NGS panel assay of known IBMFS genes. After analysis for point mutations, heterozygous and homozygous CNVs were searched by normalized read coverage ratios and specific thresholds. Of the 258 tested patients, 91 were found to have pathogenic point variants. NGS sample data from 165 patients without pathogenic point mutations were re-analyzed for CNVs; 10 patients were found to have deletions. Diamond Blackfan anemia genes most commonly exhibited heterozygous deletions, and included RPS19, RPL11, and RPL5. A diagnosis of GATA2-related disorder was made in a patient with myelodysplastic syndrome who was found to have a heterozygous GATA2 deletion. Importantly, homozygous FANCA deletion were detected in a patient who could not be previously assigned a specific syndromic diagnosis. Lastly, we identified compound heterozygousity for deletions and pathogenic point variants in RBM8A and PARN genes. All deletions were validated by orthogonal methods. We conclude that careful analysis of normalized coverage values can detect CNVs in NGS panels and should be considered as a standard practice prior to do further investigations.

The clinical impact of copy number variants in inherited bone marrow failure syndromes.

Inherited bone marrow failure syndromes (IBMFSs) comprise a genetically heterogeneous group of diseases with hematopoietic failure and a wide array of physical malformations. Copy number variants (CNVs) were reported in some IBMFSs. It is unclear what impact CNVs play in patients evaluated for a suspected diagnosis of IBMFS. Clinical and genetic data of 323 patients from the Canadian Inherited Marrow Failure Registry from 2001 to 2014, who had a documented genetic work-up, were analyzed. Cases with pathogenic CNVs (at least 1 kilobasepairs) were compared to cases with other mutations. Genotype-phenotype correlations were performed to assess the impact of CNVs. Pathogenic nucleotide-level mutations were found in 157 of 303 tested patients (51.8%). Genome-wide CNV analysis by single nucleotide polymorphism arrays or comparative genomic hybridization arrays revealed pathogenic CNVs in 11 of 67 patients tested (16.4%). In four of these patients, identification of CNV was crucial for establishing the correct diagnosis as their clinical presentation was ambiguous. Eight additional patients were identified to harbor pathogenic CNVs by other methods. Of the 19 patients with pathogenic CNVs, four had compound-heterozygosity of a CNV with a nucleotide-level mutation. Pathogenic CNVs were associated with more extensive non-hematological organ system involvement (p=0.0006), developmental delay (p=0.006) and short stature (p=0.04) compared to nucleotide-level mutations. In conclusion, a significant proportion of patients with IBMFSs harbor pathogenic CNVs which were associated with a more extensive non-hematological phenotype in this cohort. Patients with a phenotype suggestive of IBMFSs but without identification of pathogenic nucleotide-level mutations should undergo specific testing for CNVs.

Response to treatment with azacitidine in children with advanced myelodysplastic syndrome prior to hematopoietic stem cell transplantation.

Advanced myelodysplastic syndrome harbors a high risk of progression to acute myeloid leukemia and poor prognosis. In children, there is no established treatment to prevent or delay progression to leukemia prior to hematopoietic stem cell transplantation. Azacitidine is a hypomethylating agent, which was shown to slow progression to leukemia in adults with myelodysplastic syndrome. There is little data on the efficacy of azacitidine in children. We reviewed 22 pediatric patients with advanced myelodysplastic syndrome from a single center, diagnosed between January 2000 and December 2015. Of those, eight patients received off-label azacitidine before hematopoietic stem cell transplantation. A total of 31 cycles were administered and modification or delay occurred in four of them due to cytopenias, infection, nausea/vomiting, and transient renal impairment. Bone marrow blast percentages in azacitidine-treated patients decreased significantly from a median of 15% (range 9-31%) at the start of treatment to 5.5% (0-12%, P=0.02) before hematopoietic stem cell transplantation. Following azacitidine treatment, four patients (50%) achieved marrow remission, and none progressed. In contrast, three untreated patients (21.4%) had progressive disease characterized by >50% increase in blast counts or progression to leukemia. Azacitidine-treated patients had significantly increased 4-year event-free survival (P=0.04); predicted 4-year overall survival was 100% versus 69.3% in untreated patients (P=0.1). In summary, azacitidine treatment prior to hematopoietic stem cell transplantation was well tolerated in pediatric patients with advanced myelodysplastic syndrome, led to partial or complete bone marrow response in seven of eight patients (87.5%), and correlated with superior event-free survival in this cohort.

Improving diagnostic precision, care and syndrome definitions using comprehensive next-generation sequencing for the inherited bone marrow failure syndromes.

BACKGROUND: Phenotypic overlap among the inherited bone marrow failure syndromes (IBMFSs) frequently limits the ability to establish a diagnosis based solely on clinical features. >70 IBMFS genes have been identified, which often renders genetic testing prolonged and costly. Since correct diagnosis, treatment and cancer surveillance often depend on identifying the mutated gene, strategies that enable timely genotyping are essential. METHODS: To overcome these challenges, we developed a next-generation sequencing assay to analyse a panel of 72 known IBMFS genes. Cases fulfilling the clinical diagnostic criteria of an IBMFS but without identified causal genotypes were included. RESULTS: The assay was validated by detecting 52 variants previously found by Sanger sequencing. A total of 158 patients with unknown mutations were studied. Of 75 patients with known IBMFS categories (eg, Fanconi anaemia), 59% had causal mutations. Among 83 patients with unclassified IBMFSs, we found causal mutations and established the diagnosis in 18% of the patients. The assay detected mutant genes that had not previously been reported to be associated with the patient phenotypes. In other cases, the assay led to amendments of diagnoses. In 20% of genotype cases, the results indicated a cancer surveillance programme. CONCLUSIONS: The novel assay is efficient, accurate and has a major impact on patient care.

Treatment of dyskeratosis congenita-associated pulmonary fibrosis with danazol.

Individuals with Dyskeratosis Congenita (DC) are at increased risk for complications in variety of systems including pulmonary fibrosis. Idiopathic and DC-associated pulmonary fibrosis are progressive and fatal disorders without known treatment. Here we describe, for the first time, marked improvement in the clinical and laboratory parameters of the pulmonary disease of a child who suffered from TINF2-associated DC and severe pulmonary fibrosis after initiation of therapy with Danazol. We recommend that the clinical efficacy of Danazol in slowing down the progression of pulmonary fibrosis in patients with telomere-related disorders is evaluated in prospective studies.

The impact of category, cytopathology and cytogenetics on development and progression of clonal and malignant myeloid transformation in inherited bone marrow failure syndromes.

Inherited bone marrow failure syndromes are a group of rare, heterogeneous genetic disorders with a risk of clonal and malignant myeloid transformation including clonal marrow cytogenetic abnormalities, myelodysplastic syndrome and acute myeloid leukemia. The clinical characteristics, risk classification, prognostic factors and outcome of clonal and malignant myeloid transformation associated with inherited bone marrow failure syndromes are largely unknown. The aims of this study were to determine the impact of category, cytopathology and cytogenetics, the three components of the "Category Cytology Cytogenetics" classification of pediatric myelodysplastic syndrome, on the outcome of clonal and malignant myeloid transformation associated with inherited bone marrow failure. We used data from the Canadian Inherited Marrow Failure Registry. Among 327 patients with inherited bone marrow failure syndrome enrolled in the registry, the estimated risk of clonal and malignant myeloid transformation by the age of 18 years was 37%. The risk of clonal and malignant myeloid transformation varied according to the type of inherited bone marrow failure syndrome but was highest in Fanconi anemia. The development of clonal and malignant myeloid transformation significantly affected overall survival. Mortality varied based on cytopathological group. The largest group of patients had refractory cytopenia. Clonal marrow cytogenetic abnormalities were identified in 87% of patients with clonal and malignant myeloid transformation, and different cytogenetic groups had different impacts on disease progression. We conclude that category, cytopathology and cytogenetics in cases of clonal and malignant myeloid transformation associated with inherited bone marrow failure syndromes have an important impact on outcome and that the classification of such cases should incorporate these factors.

Decisional regret after distal hypospadias repair: single institution prospective analysis of factors associated with subsequent parental remorse or distress.

PURPOSE: Hypospadias repair is a commonly performed procedure. Little is known about decisional regret in parents who agree to proceed with this surgical reconstruction. We present data on this previously underexplored issue. MATERIALS AND METHODS: We performed followup analysis of 100 couples prospectively evaluated after counseling for surgical correction of distal hypospadias in their son with assessment of complications and decisional regret 1 year after surgery. Findings were contrasted with baseline demographics, hypospadias knowledge and decisional conflict at the time of counseling. RESULTS: Decisional regret was found in 116 parents, including mild regret in 41.4% and moderate to severe regret in 8.6%. There was no statistically significant difference in paired regret analysis between mothers and fathers. Complications were strongly associated with decisional regret (p <0.001). On regression analysis postoperative complications (OR 14.7, 95% CI 1.6-131.6), parental desire to avoid circumcision (OR 7.4, 95% CI 1.1-49.4) and initial decisional conflict level (OR 1.06, 95% CI 1.02-1.09) were statistically significant predictors of moderate to strong decisional regret. These findings remained robust after imputation strategies to address missing data. The impact of decisional conflict and preference for circumcision were significant even after excluding families who experienced complications. CONCLUSIONS: To our knowledge this is the first study demonstrating parental decisional regret after providing consent for surgical correction of distal hypospadias in their son. Based on the described risk factors efforts aimed at minimizing complications and counseling about foreskin preservation techniques may be prudent to ameliorate decisional regret. The novel association between decisional conflict and regret suggests that conflict assessment during counseling may help screen families at risk for postoperative regret.

Combined de-novo mutation and non-random X-chromosome inactivation causing Wiskott-Aldrich syndrome in a female with thrombocytopenia.

OBJECTIVE: Disorders linked to mutations in the X chromosomes typically affect males. The aim of the study is to decipher the mechanism of disease expression in a female patient with a heterozygous mutation on the X-chromosome. PATIENTS AND METHODS: Clinical data was extracted from the Canadian Inherited Marrow Failure Registry. Genomic ribonucleic acid (DNA) and complementary DNA (cDNA) underwent Sanger sequencing. Protein analysis was performed by flow cytometry. X-inactivation patterns were analyzed by evaluating the DNA methylation status and cDNA clonal expression of several genes on the X-chromosome. SNP array was used for molecular karyotyping of the X-chromosome. RESULTS: A female with thrombocytopenia, eczema and mild T-lymphocyte abnormalities with extensive negative diagnostic testing, was suspected to have Wiskott-Aldrich syndrome (WAS)/X-linked thrombocytopenia. Although the girl had a mutation (c.397G > A, p.E133K) in only one allele, she was found to have an extremely skewed X-inactivation pattern and no expression of the WAS protein. Family studies using DNA methylation analysis and cDNA clonal expression of several genes on the X-chromosome demonstrated that the patient developed de-novo non-random inactivation of the X-chromosome that does not carry the mutation. Genome-wide high-density molecular karyotyping excluded deletions and amplifications as a cause for the non-random inactivation of one X-chromosome. CONCLUSIONS: Our study emphasizes the need to test selected female patients with complete or incomplete disease expression for X-linked disorders even in the absence of a family history.

Analysis of decisional conflict among parents who consent to hypospadias repair: single institution prospective study of 100 couples.

PURPOSE: Although obtaining informed consent for distal hypospadias repair is common practice, little is known about the uncertainty or conflict between consenting parents faced with this decision. We systematically evaluated decisional conflict between parents who elected to have their child undergo hypospadias surgery. MATERIALS AND METHODS: A total of 100 couples who were counseled about treatment options agreed to participate. Using a validated questionnaire, the Decisional Conflict Scale, we prospectively collected data on decisional conflict demographics, preference for circumcision, education level and prior knowledge about hypospadias. RESULTS: All parents elected surgical repair. Evidence of decisional conflict was encountered in 28% of participants (score less than 25 in 72%, 25 to 37.5 in 23.5%, greater than 37.5 in 4.5%). No statistically significant differences among parents were noted for total score (mean ± SD 16.1 ± 12 in mothers and 18.3 ± 12.6 in fathers) or subscales, except the informed subscale (mean ± SD 16.7 ± 14.3 in mothers and 21.1 ± 16.6 in fathers). Parental self-report of prior knowledge about hypospadias and preference for neonatal circumcision correlated with lower Decisional Conflict Scale scores (p = 0.02 and p <0.01, respectively). No statistical association was found between score and parental education level (p = 0.7) or expertise of the counselor (staff vs pediatric urology fellow, p = 0.4). CONCLUSIONS: These data describe the level of decisional conflict in couples agreeing to proceed with hypospadias repair, with no evidence of significant discrepancy between them. The novel description of factors related to decreased decisional conflict might help focus efforts aimed at minimizing difficulties encountered during the decision making process.