The role of pediatric oncologist in prenatal diagnosis: A 10-year retrospective study at Assistance Publique Hôpitaux de Marseille (AP-HM).

Solid tumors or predisposition syndromes are increasingly suspected before birth. However optimal management and outcomes remain unclear. We have performed a ten-year retrospective study of oncologic indications of prenatal diagnosis in public hospitals in Marseille. Data were obtained from prenatal diagnosis center and hospital imaging databases and pediatric oncology department files. Fifty-one cases were identified, 40 with mass: adrenal 17, sacrococcygeal 9, cardiac 7, abdominal 4, ovarian 1, cervical 2; 8 with developmental abnormalities (omphalocele 4, macroglossia 4), 3 WITH familial predisposition syndromes (familial rhabdoid 2, Li-Fraumeni 1). Median detection time was 30 week. Termination of pregnancy was decided for 9 fetuses (4 cardiac lesions and suspected tuberous sclerosis, 2 sacrococcygeal tumors, 1 Beckwith-Wiedemann Syndrome, 2 SMARCB1 mutations. Preterm birth occurred in 8 cases. Eleven newborns (26,1%) required intensive care (8 for mechanical complications). Of of 17 adrenal mass ES, 4 disappeared before birth and 5 before one year. Seventeen newborns underwent surgery: 13 masses (teratoma 7, myelomeningocele 2, cystic nephroma 1, neuroblastoma 2), 4 omphaloceles, one biopsy. Surgery performed after one year for incomplete regression identified 1 neuroblastoma, 2 bronchogenic cysts and 2 nonmalignant masses. Three newborns received chemotherapy. Except one patient with BWS who died of obstructive apnea, all children are alive disease free with a median follow-up of 60 months [9-131 months]. Twelve have sequelae. Various solid tumors and cancer predisposition syndromes can be detected before birth. A multidisciplinary collaboration is strongly recommended for optimal management before and after birth.

Mutational analysis of apoptotic genes in familial aggregation of hematological malignancies.

INTRODUCTION: Apoptosis deregulation have been associated to tumorigenesis process and was highlighted as a prominent hallmark of cancer. Several mutations have been reported in several forms of Blood cancer. However, it has never been investigated in familial aggregations of hematological malignancies. METHODS: In this study, we performed a mutational analysis by sequencing the entire coding regions in four key apoptotic genes FAS, FASLG, CASP8 and CASP10 in 92 independent families belonging to French and Tunisian populations and diagnosed with several forms of familial hematological malignancies. RESULTS: We report 15 genetic variations among which 7 were previously reported in several form of cancers and have a potential effect on gene expression. Particularly, the CASP8 variants p.Asp302His and p.Lys337Lys were detected in 15% and 10% of our group of patients respectively and were previously reported in association to breast cancer and to breast cancer susceptibility. DISCUSSION: In this study, we do not report the underlining deleterious mutations in familial hematological malignancies, but we describe some variants with potential risk of developing blood cancer. To gain further insights on the association between apoptosis pathway deregulation and familial hematological malignancies, more apoptotic genes should be investigated.

Medulloblastomas associated with an APC germline pathogenic variant share the good prognosis of CTNNB1-mutated medulloblastomas.

BACKGROUND: Medulloblastomas may occur in a predisposition context, including familial adenomatosis polyposis. Medulloblastomas related to a germline pathogenic variant of adenomatous polyposis coli (APC) remain rare and poorly described. Their similarities with sporadic WNT medulloblastomas still require description. METHODS: We performed a multicentric retrospective review of 12 patients treated between 1988 and 2018 for medulloblastoma with an identified or highly suspected (personal or familial history) APC germline pathogenic variant. We report personal and familial history APC gene pathogenic variants whenever available: clinical and histologic characteristics of the medulloblastoma, treatments, and long-term outcome, including second tumor and late sequelae. RESULTS: Medulloblastomas associated with APC pathogenic variants are mainly classic (11/11 patients, 1 not available), nonmetastatic (10/12 patients) medulloblastomas, with nuclear immunoreactivity for ß-catenin (9/9 tested cases). Ten of 11 assessable patients are disease free with a median follow-up of 10.7 years (range, 1-28 y). Secondary tumors included desmoid tumors in 7 patients (9 tumors), 1 thyroid carcinoma, 2 pilomatricomas, 1 osteoma, 1 vertebral hemangioma, and 1 malignant triton in the radiation field, which caused the only cancer-related death in our series. CONCLUSIONS: Medulloblastomas associated with an APC pathogenic variant have an overall favorable outcome, even for metastatic tumors. Yet, long-term survival is clouded by second tumor occurrence; treatment may play some role in some of these second malignancies. Our findings raise the question of applying a de-escalation therapeutic protocol to treat patients with APC germline pathogenic variants given the excellent outcome, and reduced intensity of craniospinal irradiation may be further evaluated.

Association of the POT1 Germline Missense Variant p.I78T With Familial Melanoma.

Importance: The protection of telomeres 1 protein (POT1) is a critical component of the shelterin complex, a multiple-protein machine that regulates telomere length and protects telomere ends. Germline variants in POT1 have been linked to familial melanoma, and somatic mutations are associated with a range of cancers including cutaneous T-cell lymphoma (CTCL). Objective: To characterize pathogenic variation in POT1 in families with melanoma to inform clinical management. Design, Setting, and Participants: In this case study and pedigree evaluation, analysis of the pedigree of 1 patient with melanoma revealed a novel germline POT1 variant (p.I78T, c.233T>C, chromosome 7, g.124870933A>G, GRCh38) that was subsequently found in 2 other pedigrees obtained from the GenoMEL Consortium. Main Outcomes and Measures: (1) Identification of the POT1 p.I78T variant; (2) evaluation of the clinical features and characteristics of patients with this variant; (3) analysis of 3 pedigrees; (4) genomewide single-nucleotide polymorphism genotyping of germline DNA; and (5) a somatic genetic analysis of available nevi and 1 melanoma lesion. Results: The POT1 p.I78T variant was found in 3 melanoma pedigrees, all of persons who self-reported as being of Jewish descent, and was shown to disrupt POT1-telomere binding. A UV mutation signature was associated with nevus and melanoma formation in POT1 variant carriers, and somatic mutations in driver genes such as BRAF, NRAS, and KIT were associated with lesion development in these patients. Conclusions and Relevance: POT1 p.I78T is a newly identified, likely pathogenic, variant meriting screening for in families with melanoma after more common predisposition genes such as CDKN2A have been excluded. It could also be included as part of gene panel testing.

Psychological impact of von Hippel-Lindau genetic screening in patients with a previous history of hemangioblastoma of the central nervous system.

Von Hippel-Lindau (VHL) syndrome is a hereditary cancer syndrome characterized by a high risk of developing benign and malignant tumors, including central nervous system hemangioblastomas (CNS HBs). For an early diagnosis of VHL, before the occurrence of cancers (especially renal cell carcinoma), it is of huge importance to initiate VHL genetic testing in at-risk patients. The aim of the study was to assess the psychological impact of VHL genetic testing in patients previously diagnosed with a CNS HB. From 1999 until 2015, 55 patients underwent surgery for CNS HBs. Eleven patients were already screened for VHL mutations and 3 patients deceased before the start of the study. From the remaining 42 patients, 24 were accepted to be enrolled in the study. Assessment of psychological impact of VHL genetic testing was performed by measuring anxiety levels, mood disorders, quality of life, and psychological consequences of genetic screening. Twenty-one of the enrolled 24 patients underwent VHL genetic testing and 12 patients came back for the communication of positive genetic results. The baseline psychological status did not differ between these 2 groups. Patients who attended the visit of communication of genetic results had similar anxiety levels compared to those who had not. Furthermore, they also experienced an improvement in the level of anxiety and two QoL dimension scores compared to their baseline status. In summary, there is no evidence of a negative psychosocial impact of VHL genetic testing in patients with a previous history of CNS HB. We, therefore, recommend the recall of patients who have not been previously screened.

Morphology and genomic hallmarks of breast tumours developed by ATM deleterious variant carriers.

BACKGROUND: The ataxia telangiectasia mutated (ATM) gene is a moderate-risk breast cancer susceptibility gene; germline loss-of-function variants are found in up to 3% of hereditary breast and ovarian cancer (HBOC) families who undergo genetic testing. So far, no clear histopathological and molecular features of breast tumours occurring in ATM deleterious variant carriers have been described, but identification of an ATM-associated tumour signature may help in patient management. METHODS: To characterise hallmarks of ATM-associated tumours, we performed systematic pathology review of tumours from 21 participants from ataxia-telangiectasia families and 18 participants from HBOC families, as well as copy number profiling on a subset of 23 tumours. Morphology of ATM-associated tumours was compared with that of 599 patients with no BRCA1 and BRCA2 mutations from a hospital-based series, as well as with data from The Cancer Genome Atlas. Absolute copy number and loss of heterozygosity (LOH) profiles were obtained from the OncoScan SNP array. In addition, we performed whole-genome sequencing on four tumours from ATM loss-of-function variant carriers with available frozen material. RESULTS: We found that ATM-associated tumours belong mostly to the luminal B subtype, are tetraploid and show LOH at the ATM locus at 11q22-23. Unlike tumours in which BRCA1 or BRCA2 is inactivated, tumours arising in ATM deleterious variant carriers are not associated with increased large-scale genomic instability as measured by the large-scale state transitions signature. Losses at 13q14.11-q14.3, 17p13.2-p12, 21p11.2-p11.1 and 22q11.23 were observed. Somatic alterations at these loci may therefore represent biomarkers for ATM testing and harbour driver mutations in potentially 'druggable' genes that would allow patients to be directed towards tailored therapeutic strategies. CONCLUSIONS: Although ATM is involved in the DNA damage response, ATM-associated tumours are distinct from BRCA1-associated tumours in terms of morphological characteristics and genomic alterations, and they are also distinguishable from sporadic breast tumours, thus opening up the possibility to identify ATM variant carriers outside the ataxia-telangiectasia disorder and direct them towards effective cancer risk management and therapeutic strategies.

Interphase FISH for BCR-ABL1 rearrangement on neutrophils: A decisive tool to discriminate a lymphoid blast crisis of chronic myeloid leukemia from a de novo BCR-ABL1 positive acute lymphoblastic leukemia.

Discrimination between lymphoid blast crisis of chronic myeloid leukemia (CML) and de novo BCR-ABL1 positive acute lymphoblastic leukemia (ALL) represents a diagnostic challenge because this distinction has a major incidence on the management of patients. Here, we report an uncommon pediatric case of ALL with cryptic ins(22;9)(q11;q34q34) and p190-type BCR-ABL1 transcript. We performed interphase fluorescence in situ hybridization (FISH) for BCR-ABL1 rearrangement on blood neutrophils, which was positive consistent with the diagnosis of lymphoid blast crisis of CML. This case illustrates the major interest of interphase FISH for BCR-ABL1 rearrangement on blood neutrophils as a decisive method to discriminate a lymphoid blast crisis of CML from a de novo BCR-ABL1 positive ALL.

Telomere length, ATM mutation status and cancer risk in Ataxia-Telangiectasia families.

Recent studies have linked constitutive telomere length (TL) to aging-related diseases including cancer at different sites. ATM participates in the signaling of telomere erosion, and inherited mutations in ATM have been associated with increased risk of cancer, particularly breast cancer. The goal of this study was to investigate whether carriage of an ATM mutation and TL interplay to modify cancer risk in ataxia-telangiectasia (A-T) families.The study population consisted of 284 heterozygous ATM mutation carriers (HetAT) and 174 non-carriers (non-HetAT) from 103 A-T families. Forty-eight HetAT and 14 non-HetAT individuals had cancer, among them 25 HetAT and 6 non-HetAT were diagnosed after blood sample collection. We measured mean TL using a quantitative PCR assay and genotyped seven single-nucleotide polymorphisms (SNPs) recurrently associated with TL in large population-based studies.HetAT individuals were at increased risk of cancer (OR = 2.3, 95%CI = 1.2-4.4, P = 0.01), and particularly of breast cancer for women (OR = 2.9, 95%CI = 1.2-7.1, P = 0.02), in comparison to their non-HetAT relatives. HetAT individuals had longer telomeres than non-HetAT individuals (P = 0.0008) but TL was not associated with cancer risk, and no significant interaction was observed between ATM mutation status and TL. Furthermore, rs9257445 (ZNF311) was associated with TL in HetAT subjects and rs6060627 (BCL2L1) modified cancer risk in HetAT and non-HetAT women.Our findings suggest that carriage of an ATM mutation impacts on the age-related TL shortening and that TL per se is not related to cancer risk in ATM carriers. TL measurement alone is not a good marker for predicting cancer risk in A-T families.

GATA2 gene analysis in several forms of hematological malignancies including familial aggregations.

The genetic predisposition to familial hematological malignancies has been previously reported highlighting inherited gene mutations. Several genes have been reported but genetic basis remains not well defined. In this study, we extended our investigation to a potential candidate GATA2 gene which was analyzed by direct sequencing in 119 cases including familial aggregations with a variety of hematological malignancies and sporadic acute leukemia belonging to Tunisian and French populations. We reported a deleterious p.Arg396Gln GATA2 mutation in one patient diagnosed with both sporadic acute myeloid leukemia (AML) and breast cancer. We also reported several GATA2 variations in familial cases. The absence of deleterious mutations in this large cohort of familial aggregations of hematological malignancies may strengthen the hypothesis that GATA2 mutations are an important predisposing factor, although as a secondary genetic event, required for the development of overt malignant disease.

[OISO, automatic treatment of patients management in oncogenetics]. / OISO, traitement informatisé de la prise en charge en oncogénétique clinique.

INTRODUCTION: Oncogenetics is a long-term process, which requires a close relation between patients and medical teams, good familial links allowing lifetime follow-up. Numerous documents are exchanged in between the medical team, which has to frequently interact. We present here a new tool that has been conceived specifically for this management. METHODS: The tool has been developed according to a model-view-controler approach with the relational system PostgreSQL 9.3. The web site used PHP 5.3, HTML5 and CSS3 languages, completed with JavaScript and jQuery-AJAX functions and two additional modules, FPDF and PHPMailer. RESULTS: The tool allows multiple interactions, clinical data management, mailing and emailing, follow-up plannings. Requests are able to follow all patients and planning automatically, to send information to a large number of patients or physicians, and to report activity. DISCUSSION: The tool has been designed for oncogenetics and adapted to its different aspects. The CNIL delivered an authorization for use. Secured web access allows the management at a regional level. Its simple concept makes it evolutive according to the constant updates of genetic and clinical management of patients.

ARLTS1, potential candidate gene in familial aggregation of hematological malignancies.

INTRODUCTION: Genetic predisposition to familial hematological malignancies was previously described through several epidemiological analyses, but the genetic basis remains unclear. The tumor-suppressor ARLTS1 gene was previously described in sporadic hematological malignancies and familial cancer context. METHODS: In this study, we sequence the ARLTS1 gene in 100 patients belonging to 88 independent Tunisian and French families. RESULTS: After gene sequencing, we report 8 genetic variations, most of which were previously reported in several cancer forms. The most common variants were W149X and C148R and were previously associated to B-cell chronic lymphocytic leukemia and to high-risk of familial breast cancer. CONCLUSIONS: These results emphasize the fact that ARLTS1 gene mutations can be considered as a potential predisposing factor in familial hematological malignancies and other several cancer forms.

Molecular combing: A new tool in diagnosing leukemia.

BACKGROUND: According to the World Health Organization (WHO), recurrent cytogenetic abnormalities define many specific groups of hematopoietic tumors of acute myeloid and lymphoblastic leukemia, and these abnormalities are often strongly associated with prognosis and sometimes require specific treatments. These rearrangements are commonly detected by conventional and molecular cytogenetic techniques. OBJECTIVE: Using an alternative method, we sought to highlight the presence of chromosomal rearrangements. METHODS: We applied molecular combing to detect and directly visualize gene fusions associated with balanced translocations found in acute leukemia. RESULTS: In patients harboring t(12;21)(p13;q22), we demonstrated the presence of the fusion using specific probes covering the ETV6 and RUNX1 genes, with a positive result occurring due to the hybridization of the two probes to the same DNA fiber. Thanks to molecular combing, we also showed the presence of different breakpoints using these same probes. CONCLUSIONS: Using several probes that are specific to the most common genes involved in acute leukemia, molecular combing could be an interesting additional tool in acute leukemia diagnosis.

Familial hematological malignancies: new IDH2 mutation.

Isocitrate dehydrogenase IDH 1 and IDH 2 mutations were reported in several cancer forms, especially in hematological malignancies, but were never been investigated in familial aggregation. The aim of this study is to determine whether germline isocitrate dehydrogenase genes mutations are involved.We targeted IDH1 and IDH2 genes in 104 familial cases belonging to Tunisian and French populations, including several forms of hematological malignancies and cosegregated solid tumors.We report one IDH1 variant: c.315 G>T, p.Gly105Gly in 15 % of cases, which was assigned to the worst outcome in several studies. Three IDH2 variants were found, among them, one intronic substitution c.543+45 G>A (rs142033117) and two new variants not previously described: c.389 A>T, p.Lys130Met and c.414 T>C, p.Thr138Thr. The p.Lys130Met was found in one case diagnosed with Waldenstrom's disease with familial history of cancer. The enrolled in silico analysis, the functional study, and the absence of this variant in control population strengthen the hypothesis of its deleterious effect.From an extended number of candidate genes analyzed in familial hematological malignancies, IDH2 might be considerably involved since we reported a potential damaging effect.

Mutational analysis of JAK2, CBL, RUNX1, and NPM1 genes in familial aggregation of hematological malignancies.

Familial aggregation of hematological malignancies has been reported highlighting inherited genetic predisposition. In this study, we targeted four candidate genes: JAK2 and RUNX1 genes assuring a prominent function in hematological process and CBL and NPM1 as proto-oncogenes. Their disruption was described in several sporadic hematological malignancies. The aim of this study is to determine whether JAK2, CBL, RUNX1, and NPM1 germline genes mutations are involved in familial hematological malignancies. Using direct sequencing, we analyzed JAK2 (exons 12 and 14); CBL (exons 7, 8 and 9); NPM1 (exon 12) and the entire RUNX1 in 88 independent families belonging to Tunisian and French populations. Twenty-one sporadic acute leukemias were included in this study. We reported a heterozygous intronic c.1641 + 6 T > C JAK2 variant (rs182123615) found in two independent familial cases diagnosed with gastric lymphoma and Hodgkin lymphoma. The in silico analysis suggested a potential impact on splicing, but the functional splicing minigene reporter assay on rs182123615 variant showed no aberrant transcripts. In one sporadic acute myeloblastic leukemia, we reported an insertion 846 in. TGTT in exon 12 of NPM1 gene that may impact the normal reading frame. The rs182123615 JAK2 variant was described in several contexts including myeloproliferative neoplasms and congenital erythrocytosis and was supposed to be pathogenic. Through this current study, we established the assessment of pathogenicity of rs182123615 and we classified it rather as rare polymorphism.

Characterization of the novel Sezary lymphoma cell line BKP1.

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of lymphomas primarily involving the skin. The most common types are mycosis fungoides (MF) and Sezary Syndrome (SS). We report a novel long-term fast-growing SS line termed BKP1 that was characterized by flow cytometry (FC), conventional and molecular cytogenetic [FISH/multi-FISH together with array comparative genomic hybridization (aCGH)]. FC immunophenotype of the BKP1 is CD2+CD5+CD3+CD4+CD8-CD7-CD25-CD26-CD30-CD158k+. The TCRγ characterization of BKP1 by PCR identified a clonal rearrangement. The conventional cytogenetic and Multi-FISH analysis showed complex chromosomal rearrangements. aCGH analysis highlighted the loss of genes involved in cell cycle control, in immune response (HLA, complement complex) and DNA damage repair mechanisms. The BKP1 is another lymphoma cell line thoroughly characterized that can be a valuable tool for both basic and applied research such as identification of deregulated genes and/or pathways and screening for new antilymphoma drugs.

Familial melanoma: clinical factors associated with germline CDKN2A mutations according to the number of patients affected by melanoma in a family.

BACKGROUND: Features associated with an increased frequency of cyclin-dependent kinase inhibitor 2A (CDKN2A) mutations have been identified in families with 3 or more patients with cutaneous melanoma (CM). However, in families with 2 patients with CM, which represent the majority of familial melanoma, these factors have been rarely studied. OBJECTIVE: We investigated association of 3 clinical features with the presence of a CDKN2A mutation in a family by extent of CM family clustering (2 vs ≥3 patients with CM among first-degree relatives in a family). METHODS: We included 483 French families that comprised 387 families with 2 patients with CM (F2 families) and 96 families with 3 or more patients with CM (F3+ families). Three clinical factors were examined individually and in a joint analysis: median age at diagnosis younger than 50 years, and 1 or more patient in a family with multiple primary melanoma or with pancreatic cancer. RESULTS: The frequency of CDKN2A mutations was higher in F3+ families (32%) than in F2 families (13%). Although early age at melanoma diagnosis and occurrence of multiple primary melanoma in 1 or more patient were significantly associated with the risk of a CDKN2A mutation in F2 families, early age at melanoma diagnosis and occurrence of pancreatic cancer in a family were significantly associated with CDKN2A mutations in F3+ families. LIMITATIONS: The study was not population based. CONCLUSIONS: This study shows that factors associated with CDKN2A mutations differ by extent of CM family clustering. It indicates that, in France, families with 2 patients with CM are eligible for genetic testing especially when there is an early age at CM diagnosis and/or 1 or more patients with multiple primary melanoma.

Molecular study of the perforin gene in familial hematological malignancies.

Perforin gene (PRF1) mutations have been identified in some patients diagnosed with the familial form of hemophagocytic lymphohistiocytosis (HLH) and in patients with lymphoma. The aim of the present study was to determine whether patients with a familial aggregation of hematological malignancies harbor germline perforin gene mutations. For this purpose, 81 unrelated families from Tunisia and France with aggregated hematological malignancies were investigated. The variants detected in the PRF1 coding region amounted to 3.7% (3/81). Two of the three variants identified were previously described: the p.Ala91Val pathogenic mutation and the p.Asn252Ser polymorphism. A new p.Ala 211Val missense substitution was identified in two related Tunisian patients. In order to assess the pathogenicity of this new variation, bioinformatic tools were used to predict its effects on the perforin protein structure and at the mRNA level. The segregation of the mutant allele was studied in the family of interest and a control population was screened. The fact that this variant was not found to occur in 200 control chromosomes suggests that it may be pathogenic. However, overexpression of mutated PRF1 in rat basophilic leukemia cells did not affect the lytic function of perforin differently from the wild type protein.

HMGA2-NFIB fusion in a pediatric intramuscular lipoma: a novel case of NFIB alteration in a large deep-seated adipocytic tumor.

Lipomas are frequently characterized by aberrations of the 12q13 approximately q15 chromosomal region and often by rearrangements of the HMGA2 gene. These rearrangements include the formation of chimeric genes that fuse the 5' region of HMGA2 with a variety of partners, such as LPP (3q28) or NFIB (9p22). We describe here the fourth reported case of lipoma showing a HMGA2-NFIB fusion, and the first one in a child. We found a translocation t(9;12)(p22;q14) in a deep-seated intramuscular lipoma occurring in the buttock of a 5-year-old boy. By fluorescence in situ hybridization and reverse-transcription polymerase chain reaction, we have shown that the translocation t(9;12) resulted in an in-frame fusion of the first four exons of HMGA2 with the last exon of NFIB. Intramuscular lipomas are very rare in childhood. Our results confirm that lipomas containing NFIB rearrangements may be related to peculiar clinicohistologic features, including large size, deep situation, infiltration of surrounding muscles, or precocious occurrence. Both the truncation of HMGA2 and the nature of its fusion partner gene might be relevant in the adipose tissue tumorigenesis.

Hidden chromosomal abnormalities in pleuropulmonary blastomas identified by multiplex FISH.

BACKGROUND: Pleuropulmonary blastoma (PPB) is a rare childhood dysontogenetic intrathoracic neoplasm associated with an unfavourable clinical behaviour. CASES PRESENTATION: We report pathological and cytogenetic findings in two cases of PPB at initial diagnosis and recurrence. Both tumors were classified as type III pneumoblastoma and histological findings were similar at diagnosis and relapse. In both cases, conventional cytogenetic techniques revealed complex numerical and structural chromosomal abnormalities. Molecular cytogenetic analysis (interphase/metaphase FISH and multicolor FISH) identified accurately chromosomal aberrations. In one case, TP53 gene deletion was detected on metaphase FISH. To date, only few cytogenetic data have been published about PPB. CONCLUSION: The PPB genetic profile remains to be established and compared to others embryonal neoplasia. Our cytogenetic data are discussed reviewing cytogenetics PPBs published cases, illustrating the contribution of multicolor FISH in order to identify pathogenetically important recurrent aberrations in PPB.