Acetylation of the lysine residues in histones and other DNA-binding proteins plays a major role in regulation of eukaryotic gene expression. This process is controlled by histone acetyltransferases (HATs/KATs) found in multiprotein complexes that are recruited to chromatin by the scaffolding subunit transformation/transcription domain-associated protein (TRRAP). TRRAP is evolutionarily conserved and is among the top five genes intolerant to missense variation. Through an international collaboration, 17 distinct de novo or apparently de novo variants were identified in TRRAP in 24 individuals. A strong genotype-phenotype correlation was observed with two distinct clinical spectra. The first is a complex, multi-systemic syndrome associated with various malformations of the brain, heart, kidneys, and genitourinary system and characterized by a wide range of intellectual functioning; a number of affected individuals have intellectual disability (ID) and markedly impaired basic life functions. Individuals with this phenotype had missense variants clustering around the c.3127G>A p.(Ala1043Thr) variant identified in five individuals. The second spectrum manifested with autism spectrum disorder (ASD) and/or ID and epilepsy. Facial dysmorphism was seen in both groups and included upslanted palpebral fissures, epicanthus, telecanthus, a wide nasal bridge and ridge, a broad and smooth philtrum, and a thin upper lip. RNA sequencing analysis of skin fibroblasts derived from affected individuals skin fibroblasts showed significant changes in the expression of several genes implicated in neuronal function and ion transport. Thus, we describe here the clinical spectrum associated with TRRAP pathogenic missense variants, and we suggest a genotype-phenotype correlation useful for clinical evaluation of the pathogenicity of the variants.Post-translational modifications including acetylation, methylation, phosphorylation, and ubiquitination, of core histones directly alter DNA-histone and histone-histone interactions and thus influence nucleosome dynamics. 1 Tight regulation of these marks is required by cells for proper gene transcription, 2 DNA repair, 3 and DNA replication. One major activator of transcription is the acetylation of histone tails, which act by neutralizing the positive charges of lysine residues or by recruiting chromatin remodelers and transcription factors. 4 This tightly regulated process is performed by histone acetyltransferases (HATs) and reversed by histone deacetylases

Congenital anomalies of the kidney and urinary tract (CAKUT) constitute one of the most frequent birth defects and represent the most common cause of chronic kidney disease in the first three decades of life. Despite the discovery of dozens of monogenic causes of CA-KUT, most pathogenic pathways remain elusive. We performed whole-exome sequencing (WES) in 551 individuals with CAKUT and identified a heterozygous de novo stop-gain variant in ZMYM2 in two different families with CAKUT. Through collaboration, we identified in total 14 different heterozygous loss-of-function mutations in ZMYM2 in 15 unrelated families. Most mutations occurred de novo, indicating possible interference with reproductive function. Human disease features are replicated in X. tropicalis larvae with morpholino knockdowns, in which expression of truncated ZMYM2 proteins, based on individual mutations, failed to rescue renal and craniofacial defects. Moreover, heterozygous Zmym2-deficient mice recapitulated features of CAKUT with high penetrance. The ZMYM2 protein is a component of a transcriptional corepressor complex recently linked to the silencing of developmentally regulated endogenous retrovirus elements. Using protein-protein interaction assays, we show that ZMYM2 interacts with additional epigenetic silencing complexes, as well as confirming that it binds to FOXP1, a transcription factor that has also been linked to CAKUT. In summary, our findings establish that loss-of-function mutations of ZMYM2, and potentially that of other proteins in its interactome, as causes of human CAKUT, offering new routes for studying the pathogenesis of the disorder.

Aberrant expression and activation of the cell cycle protein E2F1 in neurons has been implicated in many neurodegenerative diseases. As a transcription factor regulating G1 to S phase progression in proliferative cells, E2F1 is often upregulated and activated in models of neuronal death. However, despite its well studied functions in neuronal death, little is known regarding the role of E2F1 in the mature brain. In the present study, we used a combined approach to study the effect of E2F1 gene disruption on mouse behavior and brain biochemistry. We identified significant age-dependent olfactory and memory related deficits in E2f1 mutant mice. In addition, we found that E2F1 exhibits punctated staining and localizes closely to the synapse. Furthermore, we found a mirroring age-dependent loss of postsynaptic protein-95 in the hippocampus and olfactory bulb as well as a global loss of several other synaptic proteins. Coincidently, E2F1 expression is significantly elevated at the ages in which behavioral and synaptic perturbations were observed. Lastly, we show that deficits in adult neurogenesis persist late in aged E2f1 mutant mice which may partially contribute to the behavior phenotypes. Taken together, our data suggest that the disruption of E2F1 function leads to specific age-dependent behavioral deficits and synaptic perturbations.

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The non‐POU domain‐containing octamer‐binding (NONO) protein is involved in multiple steps of gene regulation such as RNA metabolism and DNA repair. Hemizygous pathogenic variants in the NONO gene were confirmed to cause a rare X‐linked syndromic disorder. Through our in‐house diagnostics and subsequent matchmaking, we identified six unrelated male individuals with pathogenic or likely pathogenic NONO variants. For a detailed comparison, we reviewed all published characterizations of the NONO‐associated disorder. The combined cohort consists of 16 live‐born males showing developmental delay, corpus callosum anomalies, non‐compaction cardiomyopathy and relative macrocephaly as leading symptoms. Seven prenatal literature cases were characterized by cardiac malformations. In this study, we extend the phenotypic spectrum through two more cases with epilepsy as well as two more cases with hematologic anomalies. By RNA expression analysis and structural modeling of a new in‐frame splice deletion, we reinforce loss‐of‐function as the pathomechanism for the NONO‐associated syndromic disorder.