BACKGROUND: Central diabetes insipidus (CDI) is a rare complication of myelodysplastic syndrome (MDS). Although the cytogenetic features of patients with MDS and CDI are not clear, CDI in patients with acute myeloid leukemia (AML) is associated with chromosome 7 and/or 3 anomalies.
METHODS: In this report, we describe two patients with MDS and concurrent CDI, and in one of them, CDI was the first manifestation. One patient had monosomy 7 on metaphase cytogenetics (MC). Monosomy 7 and numerous cytogenetic abnormalities were found in the other patient using single-nucleotide polymorphism array (SNP-A) karyotyping, while the MC did not uncover monosomy 7. In this manuscript we also reviewed reported cases of MDS with diabetes insipidus (DI-MDS) to summarize the relationship between DI-MDS and karyotype, and explore the best treatment strategy for DI-MDS.
CONCLUSIONS: DI-MDS is closely related to monosomy 7. Allogeneic hematopoietic stem cell transplantation may be the only effective treatment for DI-MDS. The SNP-A-based karyotyping is helpful to reveal subtle cytogenetic abnormalities and unveil their roles in the clinical features of MDS.

Acute myeloid leukemia (AML) is unusually associated with diabetes insipidus (DI) in patients bearing monosomy 7 or chromosome 3 aberrations. To date, 84 cases have been reported worldwide. Physiopathological mechanisms linking these chromosomal abnormalities to DI are not yet understood. We report two patients with AML/DI and review the medical literature on those conditions.

Acute myeloid leukemia with myelodysplastic changes and monosomy 7 is a rare form of pediatric leukemia associated with very poor disease-free survival. The refractoriness of the disease is due to the protection offered by the bone marrow niche, making leukemic stem cells impervious to whatever chemotherapy or myeloablative regimen is chosen. Using a mobilizing agent for haematopoietic stem cells, Plerixafor, could sensitise leukemic cells to the myeloablative therapy. This approach was not previously used in a pediatric population, and in adult populations, was used in combination with busulphan with no difference in overall survival. We describe the case of a 4-year-old boy affected by refractory acute myeloid leukemia with myelodysplastic changes and monosomy 7. The child had never achieved a remission. We proposed a combined time-scheduled scheme of therapy with plerixafor and melphalan. Combining pharmacokinetics of plerixafor with pharmacokinetics and rapid and elevated myeloablative potential of melphalan in high dosage (200 mg/m²), we succeeded in mobilizing more than 85% of stem blasts immediately before infusion of Melphalan. The count of residual blasts after 8 h from melphalan infusion was only 1.3 cells/μL. The child achieved an engraftment at day +32 with full donor chimerism. Sixteen months after haematopoietic stem cell transplantation (HSCT), he is well and in complete remission. Our case suggests that the use of plerixafor before a conditioning therapy with melphalan could induce remission in acute myeloid leukemia refractory to the usual conditioning therapy in pediatric patients. This work adds strength to the body of knowledge regarding the \"personalized\" conditioning regimen for high-risk leukemic patients.

Inherited bone marrow failure syndromes (IBMFS) are rare cancer predisposition syndromes with an especially high risk of transformation to myelodysplastic syndrome (MDS) and/or acute myeloid leukemia (AML). We performed a retrospective systematic review of reported MDS/AML arising in the eight most common IBMFS to determine the frequency and outcome of chromosome 7 abnormalities. We identified 738 MDS/AML cases of 4,293 individuals. Monosomy 7 or del (7q) occurred in ∼17%. Greater understanding of the roles played by sequential acquisition of genetic and cytogenetic changes will provide insights into myeloid leukemogenesis and improve the surveillance and hopefully outcomes for individuals with IBMFS.

Monosomy 7 arises as a recurrent chromosome aberration in donor cell leukemia after hematopoietic stem cell transplantation. We report a new case of donor cell leukemia with monosomy 7 following HLA-identical allogenic bone marrow transplantation for severe aplastic anemia (SAA). The male patient received a bone marrow graft from his sister, and monosomy 7 was detected only in the XX donor cells, 34 months after transplantation. The patient\'s bone marrow microenvironment may have played a role in the leukemic transformation of the donor hematopoietic cells.