A case series of familial ARID1B variants illustrating variable expression and suggestions to update the ACMG criteria

ARID1B is one of the most frequently mutated genes in intellectual disability (~1%). Most variants are readily classified, since they are de novo and are predicted to lead to loss of function, and therefore classified as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) guidelines for the interpretation of sequence variants. However, familial loss-of-function variants can also occur and can be challenging to interpret. Such variants may be pathogenic with variable expression, causing only a mild phenotype in a parent. Alternatively, since some regions of the ARID1B gene seem to be lacking pathogenic variants, loss-of-function variants in those regions may not lead to ARID1B haploinsufficiency and may therefore be benign. We describe 12 families with potential loss-of-function variants, which were either familial or with unknown inheritance and were in regions where pathogenic variants have not been described or are otherwise challenging to interpret. We performed detailed clinical and DNA methylation studies, which allowed us to confidently classify most variants. In five families we observed transmission of pathogenic variants, confirming their highly variable expression. Our findings provide further evidence for an alternative translational start site and we suggest updates for the ACMG guidelines for the interpretation of sequence variants to incorporate DNA methylation studies and facial analyses

Inherited variants in CHD3 show variable expressivity in Snijders Blok-Campeau syndrome

Purpose: Common diagnostic next-generation sequencing strategies are not optimized to identify inherited variants in genes associated with dominant neurodevelopmental disorders as causal when the transmitting parent is clinically unaffected, leaving a significant number of cases with neurodevelopmental disorders undiagnosed. Methods: We characterized 21 families with inherited heterozygous missense or protein-truncating variants in CHD3, a gene in which de novo variants cause Snijders Blok-Campeau syndrome. Results: Computational facial and Human Phenotype Ontology–based comparisons showed that the phenotype of probands with inherited CHD3 variants overlaps with the phenotype previously associated with de novo CHD3 variants, whereas heterozygote parents are mildly or not affected, suggesting variable expressivity. In addition, similarly reduced expression levels of CHD3 protein in cells of an affected proband and of healthy family members with a CHD3 protein-truncating variant suggested that compensation of expression from the wild-type allele is unlikely to be an underlying mechanism. Notably, most inherited CHD3 variants were maternally transmitted. Conclusion: Our results point to a significant role of inherited variation in Snijders Blok-Campeau syndrome, a finding that is critical for correct variant interpretation and genetic counseling and warrants further investigation toward understanding the broader contributions of such variation to the landscape of human disease

Health literacy and health-related quality of life in patients with anorectal malformations: A comparison between a charity hospital in Honduras and a tertiary care center in the United States

© 2018 Elsevier Inc. Background/purpose: We conduct an annual medical mission to Hospital Ruth Paz para Niños Quemados y Cirugía Pediátrica in Honduras to operate on cases of anorectal malformations (ARM). To improve our knowledge of these patients, we compared their health-related quality of life (HRQoL), and the health literacy of their caregivers from this hospital and ours in the United States. Methods: The BRIEF Health Literacy Screen (BHLS) and Pediatric Quality of Life Inventory 4.0 (PedsQL) were used, respectively, to assess the health literacy and HRQoL of their guardians. All patients scheduled for an ARM-related operation in October 2016 were eligible for inclusion, and a matched population was selected in Nationwide Children\u27s Hospital, Columbus, Ohio. Results: The sample comprised 127 patients, with 22 from Honduras and 105, the US. About 13.6% and 80% of Honduran and American caregivers, respectively, had adequate literacy. Honduran and American caregivers of patients aged 12 months and below rated the HRQoL of their children at 87 and 82, respectively; aged between two and four years, at 84 and 77; aged between two and four years, at 85 and 79; and of teens, at 59 and 66. For adults, the rate was 71 and 77 in Honduras and the US, respectively. Conclusion: Although health literacy is extremely low in the Honduran group, its HRQoL was comparable to that of its American counterpart. Improving health literacy by educating caregivers could be an additional goal for medical missions in the future. Level of Evidence: Level II

Does clinic visit education within a multidisciplinary center improve health literacy scores in caregivers of children with complex colorectal conditions?

© 2017 Introduction Health literacy is low in an estimated one-third of the US population. Little is known about the health literacy of caregivers of children with colorectal conditions. The objective of this study was to investigate whether a timed health literacy intervention could improve health literacy in this population. Methods We used the BRIEF Health Literacy screening (BHLS) tool on caregivers of children who came to our colorectal clinic. Health literacy was categorized as inadequate, marginal, or adequate. The number of caregivers with adequate health literacy was compared to the number of clinic visits and socioeconomic status. Results We included 233 caregivers. The average number of clinic visits was 3.5 over 1.2 years. At the first clinic visit, 70% (n = 98) of caregivers had “adequate” health literacy. Scores improved to 88% (p = 0.024) after the fourth visit. Socioeconomic factors were not associated with health literacy. Patients of caregivers with “adequate” health literacy visited our clinic 3.8 times, compared to 2.7 times for those with lower literacy (p = 0.006). Conclusion Emphasis on providing an education-based approach at each visit increased health literacy significantly. As expected, health literacy was lowest during the first visit, which we believe is the optimal time to implement educational interventions. Type of study Case Control/Retrospective Comparative Study. Level of evidence Level III

The use of rotational fluoroscopy and 3-D reconstruction in the diagnosis and surgical planning for complex cloacal malformations

© 2019 Elsevier Inc. Introduction: Cloacal malformations, a confluence of the urinary tract, vagina and rectum into a single common channel, has a broad and complex anatomic spectrum requiring an imaging tool for visualization, measurement, and surgical planning for the reconstruction of these structures. We evaluated the role of 3-D fluoroscopy for this purpose, as it offers a combination of spatial correlation with precise anatomic measurements. Methods: We examined our imaging protocol for patients with a cloacal malformation and report our experience with rotational fluoroscopy and 3-D reconstruction in 16 consecutive patients referred for cloacal reconstruction. The length of the common channel (CC), the length of the urethra from the bladder neck to the common channel, and the height (and existence or absence) of a vagina or vaginas were determinants of the surgical procedures used for the repair. Results: We performed 16 consecutive 3-D cloacagrams (age range 4 months to 9 years) using a new protocol (Figure 1) that provided the following data which helped with surgical planning: Gynecologic: 3 cases with a single vagina, 5 cases with a duplicated Mullerian system (3 of which were asymmetric) and 2 cases with high vaginas requiring vaginal replacement. Colorectal: Four had a high rectum requiring an abdominal approach, and 6 had a rectum reachable via a posterior sagittal approach. Urologic: Two ectopic ureters requiring reimplantation, 3 patients had vesicoureteral reflux (1 bilateral, 2 unilateral), 1 patient had no bladder, and 7 had a normal sized bladder. Common channel length and urethral length were demonstrated in all cases and used to decide between a total urogenital mobilization or a separation of vagina(s) from the common channel, urogenital separation. Conclusion: The 3-D cloacagram can help predict the surgical plan for urologic, gynecologic, and colorectal components of the cloacal repair. It can predict the CC length as well as the length of the urethra. It helps with predicting the need for vaginal replacement and whether an abdominal approach is needed for the rectum. Its effectiveness is based on the ability to adequately distend structures and see their distal most extent, an advantage over other modalities such as MRI. Added benefits (particularly from the 3D view) include a better spatial understanding of the defect and the diagnosis of concomitant urological abnormalities such as vesicoureteral reflux and ectopic ureters. Disadvantages to this procedure include the need for general anesthesia and a higher exposure to radiation. Level of evidence: 3

A structured bowel management program for patients with severe functional constipation can help decrease emergency department visits, hospital admissions, and healthcare costs

© 2018 Background: Published health-care costs related to constipation in children in the USA are estimated at $3.9 billion/year. We sought to assess the effect of a bowel management program (BMP) on health-care utilization and costs. Methods: At two collaborating centers, BMP involves an outpatient week during which a treatment plan is implemented and objective assessment of stool burden is performed with daily radiography. We reviewed all patients with severe functional constipation who participated in the program from March 2011 to June 2015 in center 1 and from April 2014 to April 2016 in center 2. ED visits, hospital admissions, and constipation-related morbidities (abdominal pain, fecal impaction, urinary retention, urinary tract infections) 12 months before and 12 months after completion of the BMP were recorded. Results: One hundred eighty-four patients were included (center 1 = 96, center 2 = 88). Sixty-three (34.2%) patients had at least one unplanned visit to the ED before treatment. ED visits decreased to 23 (12.5%) or by 64% (p \u3c 0.0005). Unplanned hospital admissions decreased from 65 to 28, i.e., a 56.9% reduction (p \u3c 0.0005). Conclusion: In children with severe functional constipation, a structured BMP decreases unplanned visits to the ED, hospital admissions, and costs for constipation-related health care. Level of evidence:

Missense variants in ANKRD11 cause KBG syndrome by impairment of stability or transcriptional activity of the encoded protein

International audiencePurpose: Although haploinsufficiency of ANKRD11 is among the most common genetic causes of neurodevelopmental disorders, the role of rare ANKRD11 missense variation remains unclear. We characterized clinical, molecular, and functional spectra of ANKRD11 missense variants.Methods: We collected clinical information of individuals with ANKRD11 missense variants and evaluated phenotypic fit to KBG syndrome. We assessed pathogenicity of variants through in silico analyses and cell-based experiments.Results: We identified 20 unique, mostly de novo, ANKRD11 missense variants in 29 individuals, presenting with syndromic neurodevelopmental disorders similar to KBG syndrome caused by ANKRD11 protein truncating variants or 16q24.3 microdeletions. Missense variants significantly clustered in repression domain 2 at the ANKRD11 C-terminus. Of the 10 functionally studied missense variants, 6 reduced ANKRD11 stability. One variant caused decreased proteasome degradation and loss of ANKRD11 transcriptional activity.Conclusion: Our study indicates that pathogenic heterozygous ANKRD11 missense variants cause the clinically recognizable KBG syndrome. Disrupted transrepression capacity and reduced protein stability each independently lead to ANKRD11 loss-of-function, consistent with haploinsufficiency. This highlights the diagnostic relevance of ANKRD11 missense variants, but also poses diagnostic challenges because the KBG-associated phenotype may be mild and inherited pathogenic ANKRD11 (missense) variants are increasingly observed, warranting stringent variant classification and careful phenotyping

A case series of familial ARID1B variants illustrating variable expression and suggestions to update the ACMG criteria

ARID1B is one of the most frequently mutated genes in intellectual disability (~1%). Most variants are readily classified, since they are de novo and are predicted to lead to loss of function, and therefore classified as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) guidelines for the interpretation of sequence variants. However, familial loss-of-function variants can also occur and can be challenging to interpret. Such variants may be pathogenic with variable expression, causing only a mild phenotype in a parent. Alternatively, since some regions of the ARID1B gene seem to be lacking pathogenic variants, loss-of-function variants in those regions may not lead to ARID1B haploinsufficiency and may therefore be benign. We describe 12 families with potential loss-of-function variants, which were either familial or with unknown inheritance and were in regions where pathogenic variants have not been described or are otherwise challenging to interpret. We performed detailed clinical and DNA methylation studies, which allowed us to confidently classify most variants. In five families we observed transmission of pathogenic variants, confirming their highly variable expression. Our findings provide further evidence for an alternative translational start site and we suggest updates for the ACMG guidelines for the interpretation of sequ

DNA methylation episignature for Witteveen-Kolk syndrome due to SIN3A haploinsufficiency

Purpose: Witteveen-Kolk syndrome (WITKOS) is a rare, autosomal dominant neurodevelopmental disorder caused by heterozygous loss-of-function alterations in the SIN3A gene. WITKOS has variable expressivity that commonly overlaps with other neurodevelopmental disorders. In this study, we characterized a distinct DNA methylation epigenetic signature (episignature) distinguishing WITKOS from unaffected individuals as well as individuals with other neurodevelopmental disorders with episignatures and described 9 previously unpublished individuals with SIN3A haploinsufficiency. Methods: We studied the phenotypic characteristics and the genome-wide DNA methylation in the peripheral blood samples of 20 individuals with heterozygous alterations in SIN3A. A total of 14 samples were used for the identification of the episignature and building of a predictive diagnostic biomarker, whereas the diagnostic model was used to investigate the methylation pattern of the remaining 6 samples. Results: A predominantly hypomethylated DNA methylation profile specific to WITKOS was identified, and the classifier model was able to diagnose a previously unresolved test case. The episignature was sensitive enough to detect individuals with varying degrees of phenotypic severity carrying SIN3A haploinsufficient variants. Conclusion: We identified a novel, robust episignature in WITKOS due to SIN3A haploinsufficiency. This episignature has the potential to aid identification and diagnosis of individuals with WITKOS

Erratum: Correction to: Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial) (BMC musculoskeletal disorders (2018) 19 1 (35))

An amendment to this paper has been published and can be accessed via the original article