Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features.

Bromodomain PHD finger transcription factor (BPTF) is the largest subunit of nucleosome remodeling factor (NURF), a member of the ISWI chromatin-remodeling complex. However, the clinical consequences of disruption of this complex remain largely uncharacterized. BPTF is required for anterior-posterior axis formation of the mouse embryo and was shown to promote posterior neuroectodermal fate by enhancing Smad2-activated wnt8 expression in zebrafish. Here, we report eight loss-of-function and two missense variants (eight de novo and two of unknown origin) in BPTF on 17q24.2. The BPTF variants were found in unrelated individuals aged between 2.1 and 13 years, who manifest variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10). Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of gene function, we observed a significant reduction in head size of F0 mutants compared to control larvae. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and phospho-histone H3 (PH3) staining to assess apoptosis and cell proliferation, respectively, showed a significant increase in cell death in F0 mutants compared to controls. Additionally, we observed a substantial increase of the ceratohyal angle of the craniofacial skeleton in bptf F0 mutants, indicating abnormal craniofacial patterning. Taken together, our data demonstrate the pathogenic role of BPTF haploinsufficiency in syndromic neurodevelopmental anomalies and extend the clinical spectrum of human disorders caused by ablation of chromatin remodeling complexes.

Phenotypic spectrum and transcriptomic profile associated with germline variants in TRAF7.

PURPOSE: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts. METHODS: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers. Phenotypic and mutational comparisons were facilitated through data exchange platforms. Whole-transcriptome sequencing was performed on RNA from patient- and control-derived fibroblasts. RESULTS: We identified heterozygous missense variants in TRAF7 as the cause of a developmental delay-malformation syndrome in 45 patients. Major features include a recognizable facial gestalt (characterized in particular by blepharophimosis), short neck, pectus carinatum, digital deviations, and patent ductus arteriosus. Almost all variants occur in the WD40 repeats and most are recurrent. Several differentially expressed genes were identified in patient fibroblasts. CONCLUSION: We provide the first large-scale analysis of the clinical and mutational spectrum associated with the TRAF7 developmental syndrome, and we shed light on its molecular etiology through transcriptome studies.

HNRNPH1-related syndromic intellectual disability: Seven additional cases suggestive of a distinct syndromic neurodevelopmental syndrome.

Pathogenic variants in HNRNPH1 were first reported in 2018. The reported individual, a 13 year old boy with a c.616C>T (p.R206W) variant in the HNRNPH1 gene, was noted to have overlapping symptoms with those observed in HNRNPH2-related X-linked intellectual disability, Bain type (MRXSB), specifically intellectual disability and dysmorphic features. While HNRNPH1 variants were initially proposed to represent an autosomal cause of MRXSB, we report an additional seven cases which identify phenotypic differences from MRXSB. Patients with HNRNPH1 pathogenic variants diagnosed via WES were identified using clinical networks and GeneMatcher. Features unique to individuals with HNRNPH1 variants include distinctive dysmorphic facial features; an increased incidence of congenital anomalies including cranial and brain abnormalities, genitourinary malformations, and palate abnormalities; increased incidence of ophthalmologic abnormalities; and a decreased incidence of epilepsy and cardiac defects compared to those with MRXSB. This suggests that pathogenic variants in HNRNPH1 result in a related, but distinct syndromic cause of intellectual disability from MRXSB, which we refer to as HNRNPH1-related syndromic intellectual disability.

Recontacting patients for multigene panel testing in hereditary cancer: Efficacy and insights.

In hereditary cancer, multigene panel testing is currently replacing older single-gene approaches. Patients whose tests were previously uninformative could benefit from updated testing. Research suggests that patients desire to be recontacted about updated genetic testing, but few studies have tested the efficacy of recontact efforts. This study investigated the outcomes of a recontact effort in a hereditary cancer clinic and explored the impact of four different recontact letters, randomized in a 2X2 factorial design. Patients who had negative genetic testing for single genes or conditions were mailed letters inviting them to schedule an appointment to discuss updated testing. Patients were randomized to receive one of four letters and each letter emphasized different implications of updated multigene genetic testing: (a) personal medical management implications, (b) implications for family members, (c) both personal and family implications or (d) a control letter. The proportion of patients who arrived for appointments was assessed approximately 7 months after mailing along with associations with patient demographics and type of letter received. Letters were mailed to 586 patients who had initial testing between 2001 and 2015. Most patients were white (78%) and female (97%) with private insurance (65%). At 7 months, 25 patients (4.3%, 95% CI: 2.6% to 5.9%) had arrived for an appointment. Older age was significantly associated with response rate (p = .01), while type of recontact letter was not (p = .54). This study suggests that recontacting patients about updated genetic testing by mail does not yield a large response. It also suggests that personal and/or familial implications do not seem to be significant factors that determine response rate. Nevertheless, results provide meaningful information for cancer clinics about the outcomes of recontact efforts via informational letter.

Twelve tips for OSCE-style Tele-assessment.

This article was migrated. The article was marked as recommended. The Australian College of Rural and Remote Medicine (ACRRM) has developed a flexible 'tele-assessment' approach to the delivery of its assessment modalities. Candidates can sit their examination remotely, close to their place of practice, which reduces the need for rural doctors - both candidates and examiners - to leave their communities for the purpose of assessment. A major component of the assessment process is the Structured Assessment using Multiple Patient Scenarios (StAMPS) examination, which blends the formats of an Objective Structured Clinical Examination (OSCE) and a traditional viva vocè examination. It is a high-stakes assessment, that was designed to be academically rigorous, flexible, valid, reliable, and fair. Since 2008 ACRRM has provided a videoconferencing option to candidates for their StAMPS examination allowing them to remain in or near their home location, while the examiners meet a central location. Travel restrictions due to the SARS-CoV-2 pandemic meant for the first time both candidates AND examiners participated in StAMPS via videoconference. ACRRM conducted an online StAMPS assessment using videoconferencing technology for 65 candidates in mid-May 2020, with all candidates, examiners and support staff remaining in or near their home communities. These Twelve Tips outline some of the experience gained in providing tele-assessment over the past twelve years.

Author Correction: CHD3 helicase domain mutations cause a neurodevelopmental syndrome with macrocephaly and impaired speech and language.

The original version of this Article contained an error in the spelling of the author Laurence Faivre, which was incorrectly given as Laurence Faive. This has now been corrected in both the PDF and HTML versions of the Article.

Author Correction: CHD3 helicase domain mutations cause a neurodevelopmental syndrome with macrocephaly and impaired speech and language.

The HTML and PDF versions of this Article were updated after publication to remove images of one individual from Figure 1.

CHD3 helicase domain mutations cause a neurodevelopmental syndrome with macrocephaly and impaired speech and language.

Chromatin remodeling is of crucial importance during brain development. Pathogenic alterations of several chromatin remodeling ATPases have been implicated in neurodevelopmental disorders. We describe an index case with a de novo missense mutation in CHD3, identified during whole genome sequencing of a cohort of children with rare speech disorders. To gain a comprehensive view of features associated with disruption of this gene, we use a genotype-driven approach, collecting and characterizing 35 individuals with de novo CHD3 mutations and overlapping phenotypes. Most mutations cluster within the ATPase/helicase domain of the encoded protein. Modeling their impact on the three-dimensional structure demonstrates disturbance of critical binding and interaction motifs. Experimental assays with six of the identified mutations show that a subset directly affects ATPase activity, and all but one yield alterations in chromatin remodeling. We implicate de novo CHD3 mutations in a syndrome characterized by intellectual disability, macrocephaly, and impaired speech and language.

Synthesis and characterization of new permanently charged poly(amidoammonium) salts and evaluation of their DNA complexes for gene transport.

A new series of linear and permanently charged poly(amidoammonium) salts were synthesized in order to investigate the influence of their ionic and hydrophobic contents on both the cytotoxicity and the transfection mediated by polycation-DNA complexes. The poly(amidoammonium) salts were prepared by chemical modification of a parent poly(amidoamine) containing two tertiary amino groups per structural unit: one incorporated into the main chain and the other fixed at the end of a short bismethylene spacer. The permanent charges were introduced through a quaternization reaction involving iodomethane or 1-iodododecane as an alkylating agent. Under appropriate conditions, the methylation reaction was found to be regioselective, allowing the quaternization of either the side chains or both the side chains and the backbone. Under physiological salt conditions (150 mM NaCl), all of the poly(amidoammonium) salts self-assembled with DNA to form complexes. High proportions of highly quaternized polycation provided better defined morphology to the polycation-DNA complexes. Complexes formed from unquaternized polycation were less cytotoxic than branched poly(ethyleneimine) (25 kDa). At high polycation-DNA weight ratios, the introduction of permanent charges generated a significant increase in the cytotoxicity, but no patent correlation could be established with the amount and the position of the permanent charges. Only complexes formed from polycations with quaternized backbone were able to generate significant gene expression, which was putatively attributed to a better defined toroidal-like morphology together with a higher stability, as suggested by zeta potential measurements. The incorporation of dodecane side chains on highly charged polycations severely amplified the cytotoxicity so that, in return, the transfection level was dramatically affected.