T cells that accompany allogeneic hematopoietic grafts for treating leukemia enhance engraftment and mediate the graft-versus-leukemia effect. Unfortunately, alloreactive T cells also cause graft-versus-host disease (GVHD). T cell depletion prevents GVHD but increases the risk of graft rejection and leukemic relapse. In human transplants, we show that donor-versus-recipient natural killer (NK)-cell alloreactivity could eliminate leukemia relapse and graft rejection and protect patients against GVHD. In mice, the pretransplant infusion of alloreactive NK cells obviated the need for high-intensity conditioning and reduced GVHD. NK cell alloreactivity may thus provide a powerful tool for enhancing the efficacy and safety of allogeneic hematopoietic transplantation.

The block of terminal differentiation is a prominent feature of acute promyelocytic leukemia (APL) and its release by retinoic acid correlates with disease remission. Expression of the APL-specific PML/RARa fusion protein in hematopoietic precursor cell lines blocks terminal differentiation, suggesting that PML/ RARa may have the same activity in APL blasts. We expressed different PML/RARa mutants in U937 and TF-1 cells and demonstrated that the integrity of the PML protein dimerization and RARa DNA binding domains is crucial for the differentiation block induced by PMLJRARc, and that these domains exert their functions only within the context of the fusion protein. Analysis of the in vivo dimerization and cell localization properties of the PML/RARa mutants revealed that PML/RARa-PML and PML/RARa-RXR heterodimers are not necssary for PML/RARa activity on differentiation. We propose that a crucial mechanism underlying PML/RARa oncogenic activity is the deregulation of a transcription factor, RARa, through its fusion with the dimerization interface of another nuclear protein, PML.

A 36-year-old patient with a disorder characterized by severe mental retardation, behavioral problems, dysmorphic face, "muscular build," and hand/foot anomalies, is reported. Following a diagnosis of de novo pericentric inversion of chromosome 8 based on standard cytogenetic analysis, a subsequent 75 kb array-CGH investigation disclosed a deletion spanning for about 13.7 Mb in the 2q31.2q32.3 region. Whole painting of chromosome 8 established the intrachromosomal nature of the rearrangement and FISH analysis with locus-specific probes confirmed the deletion on the long arm of chromosome 2. The deleted region, clinical outcome, and medical history in this patient are mainly superimposable to those reported in a published 8-year-old boy, suggesting that this genomic segment is prone to rearrangements and its hemizygosity gives rise to a clinically recognizable syndrome. The role of some genes mapping in the deleted region and related with distinct disorders is discussed. Interestingly, deletion of MSTN gene, a negative regulator of muscle growth, was associated in our patient with a "muscular build," a feature which could be regarded as a handle for clinical recognition of this syndrome.

Mutations of the MED12 gene have been reported mainly in males with FG (Opitz-Kaveggia), Lujan-Fryns, or X-linked Ohdo syndromes. Recently, a different phenotype characterized by minor anomalies, severe intellectual disability (ID), and absent language was reported in female and male patients belonging to the same family and carrying a frameshift MED12 mutation (c.5898dupC). Here, we report on two brothers and their niece affected by severe and mild ID, respectively, where whole exome sequencing combined with variant analysis within a panel of ID-related genes, disclosed a novel c.2312T>C (p.Ile771Thr) MED12 mutation. This variant, which has not been reported as a polymorphism, was not present in a third unaffected brother, and was predicted to be deleterious by five bioinformatic databases. This finding together with the phenotypic analogies shared with the carriers of c.5898dupC mutation suggests the existence of a fourth MED12-related disorder, characterized by severe ID, absent or deficient language and, milder, clinical manifestation in heterozygotes. We have reviewed the literature on MED12 heterozygotes, their clinical manifestations, and discuss the possible biological causes of this condition. © 2016 Wiley Periodicals, Inc.

We report on a 9-year-old female patient with facial anomalies and developmental delay, heterozygous for three de novo rearrangements: a paracentric inversion of chromosome 7, an apparently balanced translocation between chromosome 1 and 7, involving the same inverted chromosome 7, detected by standard cytogenetic analysis [46,XX, der(7) inv(7)(q21.1q32.1)t(1;7)(q23q32.1)]; and a 2p16.1 deletion, spanning about 3.5 Mb of genomic DNA, shown by SNP-array analysis [arr 2p16.1 (56,706,666-60,234,485)x1 dn]. Clinical features and cytogenetic imbalance in our patient were similar to those reported in five published cases, suggesting that this genomic region is prone to recombination and its hemizygosity results in a distinct although variable spectrum of clinical manifestations.