Pediatric Donor Cell Acute Lymphoblastic Leukemia Following Bone Marrow Transplant for GATA2 Mutation.

Donor cell leukemia is a rare complication following hematopoietic stem cell transplant (HSCT). There are currently few reports in children and only rare, reported cases of donor-derived myelodysplastic syndrome/acute myeloid leukemia in patients with an underlying germline GATA2 mutation. Most reported cases are myeloid in origin and occur following related HSCT. We present a 3-year-old female who developed a donor-derived B-cell acute lymphoblastic leukemia 2 years post unrelated HSCT for GATA2 germline mutation.

It Takes a Village: Providing International Pediatric Pathology Services in a Resource-Limited Setting

OBJECTIVES: Partnerships between low- to middle-income countries (LMICs) and high-income countries (HICs) is one strategy to mitigate observed health disparities. Cambodia's Angkor Hospital for Children (AHC), an LMIC institution, faces shortages in health care resources, including pathology services. A partnership was created with Children's Wisconsin (CW), an HIC hospital, including provision of pathology services. We describe our established pathology workflow, examine cases seen in AHC patients, and evaluate the impact of CW's interpretations. METHODS: AHC provides clinical history and impression and ships samples to CW, which processes the samples, and pathologists provide interpretations, sending reports electronically to AHC. For analysis, final diagnoses were considered "concordant," "refined," or "discordant" based on agreement with the clinical impression. Cases were also classified as "did not change management" or "changed management" based on how CW interpretation affected clinical management. RESULTS: We included 347 specimens (177 malignant, 146 benign, 24 insufficient for diagnosis). Of these cases, 31% were discordant and 44% of cases with clinical follow-up had a change in management with CW interpretation. CONCLUSIONS: Inclusion of pathology services in LMIC-HIC partnerships is crucial for resolving health disparities between the institutions involved. The described partnership and established pathology workflow can be adapted to the needs and resources of many institutions.

A complex KMT2A::AFF3 fusion resulting from a three-way chromosomal rearrangement in pediatric B lymphoblastic leukemia.

The KMT2A::AFF3 fusion, t(2;11)(q11.2;q23.2), is a very rare fusion occurring in pediatric B-cell acute lymphoblastic leukemia (B-ALL). Our patient is a 2-year-old male who presented with three weeks of intermittent fever. Bone marrow biopsy showed 82% blasts and cytogenetic analysis demonstrated a complex 3-way chromosomal rearrangement involving KMT2A and an unknown fusion partner. Molecular testing identified the fusion partner as AFF3, a FLT3-TKD non-D835 mutation, and an NF1 mutation. This case demonstrates a highly complex three-way variant translocation resulting in the rare KMT2A::AFF3 fusion with only a few cases previously described in the literature.

Cytogenetic features of human trophoblast cell lines SWAN-71 and 3A-subE.

Immortalization of primary cells with telomerase is thought to maintain normal phenotypic properties and avoid chromosomal abnormalities and other cancer-associated changes that occur following simian virus 40 tumor antigen (SV40 Tag) induced immortalization. However, we report that the human telomerase reverse transcriptase (hTERT)-immortalized SWAN-71 trophoblast cell line has a near pentaploid 103∼119,XXXX[cp20] karyotype. Additionally, DNA typing analysis indicated that SWAN-71 cells have acquired microsatellite instability. In comparison, the post-crisis SV40-transformed trophoblast cell line 3A-subE was hypertriploid 69∼81,XX[cp20]. Both cell lines contained multiple specific clonal rearrangements. These findings emphasize the need to monitor for genetic instability in hTERT-immortalized cells.

Hsp31 Is a Stress Response Chaperone That Intervenes in the Protein Misfolding Process.

The Saccharomyces cerevisiae heat shock protein Hsp31 is a stress-inducible homodimeric protein that is involved in diauxic shift reprogramming and has glyoxalase activity. We show that substoichiometric concentrations of Hsp31 can abrogate aggregation of a broad array of substrates in vitro. Hsp31 also modulates the aggregation of α-synuclein (αSyn), a target of the chaperone activity of human DJ-1, an Hsp31 homolog. We demonstrate that Hsp31 is able to suppress the in vitro fibrillization or aggregation of αSyn, citrate synthase and insulin. Chaperone activity was also observed in vivo because constitutive overexpression of Hsp31 reduced the incidence of αSyn cytoplasmic foci, and yeast cells were rescued from αSyn-generated proteotoxicity upon Hsp31 overexpression. Moreover, we showed that Hsp31 protein levels are increased by H2O2, in the diauxic phase of normal growth conditions, and in cells under αSyn-mediated proteotoxic stress. We show that Hsp31 chaperone activity and not the methylglyoxalase activity or the autophagy pathway drives the protective effects. We also demonstrate reduced aggregation of the Sup35 prion domain, PrD-Sup35, as visualized by fluorescent protein fusions. In addition, Hsp31 acts on its substrates prior to the formation of large aggregates because Hsp31 does not mutually localize with prion aggregates, and it prevents the formation of detectable in vitro αSyn fibrils. These studies establish that the protective role of Hsp31 against cellular stress is achieved by chaperone activity that intervenes early in the protein misfolding process and is effective on a wide spectrum of substrate proteins, including αSyn and prion proteins.

Intermediate MCAD Deficiency Associated with a Novel Mutation of the ACADM Gene: c.1052C>T.

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is an autosomal recessive disorder that leads to a defect in fatty acid oxidation. ACADM is the only candidate gene causing MCAD deficiency. A single nucleotide change, c.985A>G, occurring at exon 11 of the ACADM gene, is the most prevalent mutation. In this study, we report a Caucasian family with multiple MCADD individuals. DNA sequence analysis of the ACADM gene performed in this family revealed that two family members showing mild MCADD symptoms share the same novel change in exon 11, c.1052C>T, resulting in a threonine-to-isoleucine change. The replacement is a nonconservative amino acid change that occurs in the C-terminal all-alpha domain of the MCAD protein. Here we report the finding of a novel missense mutation, c.1052C>T (p.Thr326Ile), in the ACADM gene. To our knowledge, c.1052C>T has not been previously reported in the literature or in any of the current databases we utilize. We hypothesize that this particular mutation in combination with p.Lys304Glu results in an intermediate clinical phenotype of MCADD.

Positive cell-free fetal DNA testing for trisomy 13 reveals confined placental mosaicism.

PURPOSE: We report on a case in which cell-free fetal DNA was positive for trisomy 13 most likely due to confined placental mosaicism. Cell-free fetal DNA testing analyzes DNA derived from placental trophoblast cells and can lead to incorrect results that are not representative of the fetus. METHODS: We sought to confirm commercial cell-free fetal DNA testing results by chorionic villus sampling and amniocentesis. These results were followed up by postnatal chromosome analysis of cord blood and placental tissue. RESULTS: First-trimester cell-free fetal DNA test results were positive for trisomy 13. Cytogenetic analysis of chorionic villus sampling yielded a mosaic karyotype of 47,XY,+13[10]/46,XY[12]. G-banded analysis of amniotic fluid was normal, 46,XY. Postnatal cytogenetic analysis of cord blood was normal. Karyotyping of tissues from four quadrants of the placenta demonstrated mosaicism for trisomy 13 in two of the quadrants and a normal karyotype in the other two. CONCLUSION: Our case illustrates several important aspects of this new testing methodology: that cell-free fetal DNA may not be representative of the fetal karyotype; that follow-up with diagnostic testing of chorionic villus sampling and/or amniotic fluid for abnormal test results should be performed; and that pretest counseling regarding the full benefits, limitations, and possible testing outcomes of cell-free fetal DNA screening is important.