Toward robust clinical genome interpretation: Developing a consistent terminology to characterize Mendelian disease-gene relationships-allelic requirement, inheritance modes, and disease mechanisms.

PURPOSE: The terminology used for gene-disease curation and variant annotation to describe inheritance, allelic requirement, and both sequence and functional consequences of a variant is currently not standardized. There is considerable discrepancy in the literature and across clinical variant reporting in the derivation and application of terms. Here, we standardize the terminology for the characterization of disease-gene relationships to facilitate harmonized global curation and to support variant classification within the ACMG/AMP framework. METHODS: Terminology for inheritance, allelic requirement, and both structural and functional consequences of a variant used by Gene Curation Coalition members and partner organizations was collated and reviewed. Harmonized terminology with definitions and use examples was created, reviewed, and validated. RESULTS: We present a standardized terminology to describe gene-disease relationships, and to support variant annotation. We demonstrate application of the terminology for classification of variation in the ACMG SF 2.0 genes recommended for reporting of secondary findings. Consensus terms were agreed and formalized in both Sequence Ontology (SO) and Human Phenotype Ontology (HPO) ontologies. Gene Curation Coalition member groups intend to use or map to these terms in their respective resources. CONCLUSION: The terminology standardization presented here will improve harmonization, facilitate the pooling of curation datasets across international curation efforts and, in turn, improve consistency in variant classification and genetic test interpretation.

Profile of Helicobacter pylori infections among children in the South Island of New Zealand (2010-2021).

BACKGROUND: Helicobacter pylori is a gram-negative gut bacterium most often acquired during childhood. International guidelines state that children with suspected H. pylori infection should be referred to a gastroenterologist for investigation via gastroscopy and biopsy. Eradication therapy should be prescribed for children with peptic ulcer disease or following a treatment risk/benefit discussion for those with an incidental gastroscopy finding. Guidelines state that for children a "test-and-treat" approach is not warranted, contrasting recommendations for adults. The aim of this study was to profile pediatric H. pylori infections in the South Island of New Zealand (NZ) to determine diagnostic and management strategies, and adherence to international guidelines. MATERIALS AND METHODS: Retrospective data for positive H. pylori tests between 2010 and 2021 were retrieved from hospitals and regional testing laboratories throughout the South Island (NZ) for children ≤18 years. Outcome data were retrieved from tertiary care hospital records; sociodemographic, testing methods, eradication therapy, and symptoms. RESULTS: Two-hundred and forty children were identified: 105 (44%) male, mean age 13.2 years (SD 4.3). Participants of Pasifika, Asian, and Middle Eastern/Latin American/African heritage were overrepresented compared to the NZ census data. Overall, 138 (58%) children were diagnosed via stool antigen tests, 78 (32%) serum, and only 24 (10%) adhered to international guidelines in being confirmed via gastroscopy. Only 59 (25%) had a record of eradication therapy, and 39/59 (66%) were retested to determine eradication success, with 32 (82%) negative tests and seven (18%) remaining positive. Of the 181 (75%) that had eradication status unknown, 66 (28%) had a retest result available with 48 (73%) testing negative and 18 (27%) positive, suggesting a substantial proportion had received eradication therapy without adhering to international guidelines. CONCLUSIONS: International guidelines were not adhered to for most children in the study cohort. Implications of this include cost, unnecessary venipuncture, and unjustified antibiotic exposure.

Knowledge Levels About Inflammatory Bowel Disease Vary Between Healthcare Professional Groups.

BACKGROUND: Inflammatory Bowel Disease (IBD) is one of the most serious chronic diseases affecting the global population. Clinical team members involved in the care of individuals with IBD should have sufficient knowledge about IBD. AIMS: The study aim was to assess IBD knowledge among four health care professional groups in New Zealand: nurses, medical students, dietitians, and pharmacists. METHODS: All four groups completed surveys on demographics, work experience, and contact with patients with IBD. All completed a validated IBD knowledge assessment questionnaire (IBD-KID2), and percentage scores with standard deviation (SD) for each group calculated and compared. RESULTS: Participants included 200 nurses, 196 medical students, 45 dietitians, and 28 pharmacists. Mean IBD-KID2 percentage scores were nurses 69.7% (SD 14.7), medical students 77.6% (SD 14.5), dietitians 87.4% (SD 8.3), and pharmacists 83.4% (SD 10.1). Nurses scored lower than other HCP (P < 0.001). Independent variables were associated (P < 0.05) with higher scores for nurses having first degree relative with IBD, access to IBD guidelines, worked with children with IBD; medical students in their clinical years of study; and dietitians with IBD-specific education. Specific items scored poorly: growth, food triggers, heritability of IBD, and nutrient absorption. CONCLUSIONS: Knowledge gaps exist among HCP that may be addressed with targeted education. Improvements in the knowledge of those caring for people with IBD may optimize patient outcomes.

Systematic Review of Diagnostic Delay for Children With Inflammatory Bowel Disease.

OBJECTIVES: Pediatric inflammatory bowel disease (IBD) is a complex inflammatory condition of the gut. Diagnosing IBD involves distinct longitudinal periods from first symptoms to primary care assessment, tertiary care referral, and then endoscopic confirmation. The term diagnostic delay (DD) is used if these periods are prolonged. The aim of this review was to amalgamate DD data for children with IBD, and identify factors associated with prolonged DD. METHODS: Six health literature databases were searched (December 2020). Inclusion criteria for papers were children diagnosed with IBD before the age of 18 years, DD central tendency data, and to report a central tendency of their DD data, cohort >10 children. For analysis, all data were weighted by cohort sample size. RESULTS: Searches identified 236 papers, and 26 were included in the final analysis with a pooled cohort of 7030 children. The overall DD periods were IBD 4.5 months [Interquartile range (IQR) 3.6-8.7 months], Crohn disease (CD) 5 months (IQR 4-7.2 months), and ulcerative colitis/indeterminate colitis/IBD-unclassified (UC/IC/IBDU) 3 months (IQR 2.2-4.9 months). The difference between subtypes was significant ( P < 0.001), with shorter DD for UC/IC/IBDU than CD ( P < 0.001) and IBD ( P < 0.001). DD periods were longer for CD than IBD ( P < 0.001). DD decreased over time for IBD ( P < 0.001) and UC ( P < 0.001) but the trend suggested an increase for CD ( P 0.069). CONCLUSIONS: This data can be used to benchmark DD for children with IBD. Individual centers could determine whether improvements to awareness or infrastructure may reduce DD in order to minimize the risk of poor outcomes.

Descriptive Epidemiology of Pediatric Inflammatory Bowel Disease in Oceania: A Systematic Review and Meta-Analysis.

OBJECTIVES: Pediatric inflammatory bowel diseases (IBDs) are chronic, idiopathic illnesses of the digestive tract, which can impact adversely on children's quality of life and burden health systems. International studies have shown these diseases are increasing. The aim was to describe pediatric IBD epidemiology across Oceania by conducting a systematic review and meta-analysis of incidence and prevalence. METHODS: Medline, EMBASE and Web of Science databases were searched in October 2022 for studies reporting rates of IBD, Crohn disease (CD), or ulcerative colitis (UC) in children (≤19 years). Several data collection methodologies were included and pooled estimates of incidence and prevalence were calculated using a random effects model with I2 measures of heterogeneity. RESULTS: Nineteen articles provided 15 incidence and 7 prevalence studies. Fourteen studies were from Australia, 8 studies from New Zealand, and no studies were found from the Pacific Islands. Study dates ranged from 1950 to 2020 with 11 studies using population-based designs. Pooled estimates for annual incidence were IBD 4.1 (3.4-4.8, I2 = 98.7), CD 2.3 (1.9-2.7, I2 = 98.6), and UC 0.9 (0.6-1.1, I2 = 96.8) per 100,000 person-years. Prevalence rates were IBD 36.0 (23.5-48.5, I2 = 98.4), CD 23.2 (6.6-39.8, I2 = 97.8), and UC 7.6 (2.7-12.5, I2 = 99.6) per 100,000 persons. CONCLUSIONS: Pediatric IBD is prevalent in Oceania with high incidence rates, particularly for CD. Low rates of IBD were observed in indigenous Australian, Maori, and New Zealand Pacific children and there were no studies from the Pacific Islands highlighting this as an area in need of further research.

Co-design and Consultation Ensure Consumer Needs Are Met: Building an eHealth Platform for Children with Inflammatory Bowel Disease.

BACKGROUND: Crohn's Colitis Care is an adult inflammatory bowel disease eHealth system. Crohn's Colitis Care required additional pediatric functionality to enable life-long records and mitigate transition inadequacies. AIM: This study describes and evaluates a consensus method developed to ensure consumer needs were met. METHODS: Pediatric-specific functionality and associated resources considered important for inclusion were developed by a clinician consensus group. This group was divided into thematic subgroups and underwent two voting rounds. The content validity index was used to determine items reaching consensus. Children with inflammatory bowel disease and their parents were later shown a descriptive list of non-clinical inclusion topics proposed by the consensus group, and asked to vote on whether topic-related functionality and resources should be included. RESULTS: The consensus process consulted 189 people in total (38 clinicians, 32 children with inflammatory bowel disease and 119 parents). There was agreement across all groups to incorporate functionality and resources pertaining to quality of life, mental health, self-management, and transition readiness; however, divergence was seen for general inflammatory bowel disease facts, your inflammatory bowel disease history, and satisfaction. Cost saw the greatest disparity, being less supported by consumers compared to clinicians. Over 75% of consumers agreed it would be okay for appointments to take longer for survey completion, and > 90% thought Crohn's Colitis Care should allow consumers to ask their treating team questions. CONCLUSIONS: Widespread consumer co-design and consultation were important in unveiling differing perspectives to ensure Crohn's Colitis Care was built to support both consumer and clinician perspectives. Consumers collaborate to create a list of functionality and resources to be included in software (left), influencing the final product build (right).

The Gene Curation Coalition: A global effort to harmonize gene-disease evidence resources.

PURPOSE: Several groups and resources provide information that pertains to the validity of gene-disease relationships used in genomic medicine and research; however, universal standards and terminologies to define the evidence base for the role of a gene in disease and a single harmonized resource were lacking. To tackle this issue, the Gene Curation Coalition (GenCC) was formed. METHODS: The GenCC drafted harmonized definitions for differing levels of gene-disease validity on the basis of existing resources, and performed a modified Delphi survey with 3 rounds to narrow the list of terms. The GenCC also developed a unified database to display curated gene-disease validity assertions from its members. RESULTS: On the basis of 241 survey responses from the genetics community, a consensus term set was chosen for grading gene-disease validity and database submissions. As of December 2021, the database contained 15,241 gene-disease assertions on 4569 unique genes from 12 submitters. When comparing submissions to the database from distinct sources, conflicts in assertions of gene-disease validity ranged from 5.3% to 13.4%. CONCLUSION: Terminology standardization, sharing of gene-disease validity classifications, and resolution of curation conflicts will facilitate collaborations across international curation efforts and in turn, improve consistency in genetic testing and variant interpretation.

A Short Knowledge Assessment Tool Is Valid and Acceptable for Adults with Inflammatory Bowel Disease.

BACKGROUND: For people with inflammatory bowel disease, validated knowledge questionnaires are valuable to identify gaps in understanding and explore the impact on disease variables. AIMS: The aim of this study was to validate the short knowledge questionnaire Inflammatory Bowel Disease Knowledge Inventory Device 2, known as IBD-KID2, for use with adults with inflammatory bowel disease. METHODS: Concurrent validity of IBD-KID2 was assessed by comparing scores with those achieved on the Crohn's and Colitis Knowledge Score (CCKNOW). IBD-KID2 reliability was assessed with test-retest completion at two time points, generalizability assessed by comparing IBD-KID2 cohort scores at different recruitment centres, and acceptability assessed using participant survey. RESULTS: Seventy-five adults with inflammatory bowel disease completed the study. The mean percentage scores achieved on the IBD-KID2 and CCKNOW were 72.8% (SD 16.0) and 49.7% (SD 18.2), respectively. There was a significant correlation between IBD-KID2 and CCKNOW scores (R 0.573, P < 0.005), confirming concurrent validity. IBD-KID2 reliability was confirmed as no significant difference was seen between scores at test and retest (mean difference -0.2, P = 0.92). Generalizability was established as no significant score difference was seen between recruitment centres after controlling for population differences. The acceptability survey showed that 49 (69%) participants preferred IBD-KID2 to the CCKNOW, 60 (85%) found the IBD-KID2 easier to complete, and 38 (53%) considered the CCKNOW as most suitable for adults. CONCLUSIONS: IBD-KID2 is a valid, reliable, and generalizable tool for measuring knowledge in adults with inflammatory bowel disease with good acceptability. IBD-KID2 is easy and quick to complete, hence limiting respondent burden.

Reevaluating the Genetic Contribution of Monogenic Dilated Cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is genetically heterogeneous, with >100 purported disease genes tested in clinical laboratories. However, many genes were originally identified based on candidate-gene studies that did not adequately account for background population variation. Here we define the frequency of rare variation in 2538 patients with DCM across protein-coding regions of 56 commonly tested genes and compare this to both 912 confirmed healthy controls and a reference population of 60 706 individuals to identify clinically interpretable genes robustly associated with dominant monogenic DCM. METHODS: We used the TruSight Cardio sequencing panel to evaluate the burden of rare variants in 56 putative DCM genes in 1040 patients with DCM and 912 healthy volunteers processed with identical sequencing and bioinformatics pipelines. We further aggregated data from 1498 patients with DCM sequenced in diagnostic laboratories and the Exome Aggregation Consortium database for replication and meta-analysis. RESULTS: Truncating variants in TTN and DSP were associated with DCM in all comparisons. Variants in MYH7, LMNA, BAG3, TNNT2, TNNC1, PLN, ACTC1, NEXN, TPM1, and VCL were significantly enriched in specific patient subsets, with the last 2 genes potentially contributing primarily to early-onset forms of DCM. Overall, rare variants in these 12 genes potentially explained 17% of cases in the outpatient clinic cohort representing a broad range of adult patients with DCM and 26% of cases in the diagnostic referral cohort enriched in familial and early-onset DCM. Although the absence of a significant excess in other genes cannot preclude a limited role in disease, such genes have limited diagnostic value because novel variants will be uninterpretable and their diagnostic yield is minimal. CONCLUSIONS: In the largest sequenced DCM cohort yet described, we observe robust disease association with 12 genes, highlighting their importance in DCM and translating into high interpretability in diagnostic testing. The other genes analyzed here will need to be rigorously evaluated in ongoing curation efforts to determine their validity as Mendelian DCM genes but have limited value in diagnostic testing in DCM at present. This data will contribute to community gene curation efforts and will reduce erroneous and inconclusive findings in diagnostic testing.

Systematic large-scale assessment of the genetic architecture of left ventricular noncompaction reveals diverse etiologies.

PURPOSE: To characterize the genetic architecture of left ventricular noncompaction (LVNC) and investigate the extent to which it may represent a distinct pathology or a secondary phenotype associated with other cardiac diseases. METHODS: We performed rare variant association analysis with 840 LVNC cases and 125,748 gnomAD population controls, and compared results to similar analyses on dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). RESULTS: We observed substantial genetic overlap indicating that LVNC often represents a phenotypic variation of DCM or HCM. In contrast, truncating variants in MYH7, ACTN2, and PRDM16 were uniquely associated with LVNC and may reflect a distinct LVNC etiology. In particular, MYH7 truncating variants (MYH7tv), generally considered nonpathogenic for cardiomyopathies, were 20-fold enriched in LVNC cases over controls. MYH7tv heterozygotes identified in the UK Biobank and healthy volunteer cohorts also displayed significantly greater noncompaction compared with matched controls. RYR2 exon deletions and HCN4 transmembrane variants were also enriched in LVNC, supporting prior reports of association with arrhythmogenic LVNC phenotypes. CONCLUSION: LVNC is characterized by substantial genetic overlap with DCM/HCM but is also associated with distinct noncompaction and arrhythmia etiologies. These results will enable enhanced application of LVNC genetic testing and help to distinguish pathological from physiological noncompaction.

Disease-specific variant pathogenicity prediction significantly improves variant interpretation in inherited cardiac conditions.

PURPOSE: Accurate discrimination of benign and pathogenic rare variation remains a priority for clinical genome interpretation. State-of-the-art machine learning variant prioritization tools are imprecise and ignore important parameters defining gene-disease relationships, e.g., distinct consequences of gain-of-function versus loss-of-function variants. We hypothesized that incorporating disease-specific information would improve tool performance. METHODS: We developed a disease-specific variant classifier, CardioBoost, that estimates the probability of pathogenicity for rare missense variants in inherited cardiomyopathies and arrhythmias. We assessed CardioBoost's ability to discriminate known pathogenic from benign variants, prioritize disease-associated variants, and stratify patient outcomes. RESULTS: CardioBoost has high global discrimination accuracy (precision recall area under the curve [AUC] 0.91 for cardiomyopathies; 0.96 for arrhythmias), outperforming existing tools (4-24% improvement). CardioBoost obtains excellent accuracy (cardiomyopathies 90.2%; arrhythmias 91.9%) for variants classified with >90% confidence, and increases the proportion of variants classified with high confidence more than twofold compared with existing tools. Variants classified as disease-causing are associated with both disease status and clinical severity, including a 21% increased risk (95% confidence interval [CI] 11-29%) of severe adverse outcomes by age 60 in patients with hypertrophic cardiomyopathy. CONCLUSIONS: A disease-specific variant classifier outperforms state-of-the-art genome-wide tools for rare missense variants in inherited cardiac conditions ( https://www.cardiodb.org/cardioboost/ ), highlighting broad opportunities for improved pathogenicity prediction through disease specificity.

Development and Validation of a Self-management Skills Assessment Tool for Children With Inflammatory Bowel Disease: The Inflammatory Bowel Disease-Skills Tasks and Abilities Record (IBD-STAR).

OBJECTIVES: For children with inflammatory bowel disease (IBD), the development of self-management skills has the potential to improve disease outcomes. No assessment tools are aimed at measuring self-management skills in this population. A tool was developed called the IBD-Skills Tasks and Abilities Record (IBD-STAR) which measures children's allocation of responsibility for specific skills. IBD-STAR contains 18 items, scored whether completed independently (score 2), with help (score 1) or not at all (score 0). METHODS: Children with IBD completed IBD-STAR; one parent and a gastroenterologist completed a series of visual analogue scales that corresponded with each IBD-STAR section. Children's IBD-STAR scores were examined against independent variables and compared with the parent and clinician visual analogue scale scores. Reliability was calculated using Cronbach's alpha. RESULTS: Twenty-five Cronbach's alpha with IBD participated, mean age 14 years (standard deviation (SD) 1.7), 14 (56%) were boys, and 21 (84%) had Crohn's disease. The mean IBD-STAR score was 27.1 (SD 5.7), equivalent to a score of 75%. Age was the only independent variable significantly associated with scores (P = 0.017). Parents consistently underestimated their children in all sections, but clinician assessments were more closely aligned. Reliability for IBD-STAR was good with an overall Cronbach's alpha of 0.84. CONCLUSION: IBD-STAR reports the allocation of responsibility for self-management skills with good agreement between children and clinician, and with comprehensible differences with their parents. Such a tool may be used to identify children with IBD in need of support or to measure the efficacy of targeted interventions.

Response pattern analysis of IBD-KID: A knowledge assessment tool for children with inflammatory bowel disease.

AIM: Paediatric inflammatory bowel disease (IBD) is a chronic relapsing condition requiring adherence to complex treatment regimens to achieve best outcomes. Adherence is frequently low in this population but can be improved by increasing disease- and treatment-related knowledge. The IBD-knowledge inventory device (IBD-KID) is a knowledge assessment tool specifically developed and validated for children with IBD. To analyse IBD-KID participant response patterns in order to review the strength of the tool. METHODS: A cohort of children with IBD completed IBD-KID, and their responses were used to assess the tool's validity and feasibility. Item response analysis assessed the item difficulty and the ability of items to discriminate between high/low scorers. The analysis considered item structure, readability and the effectiveness of multiple choice items. RESULTS: A total of 105 completed IBD-KID assessments showed that 12 items (52%) had an acceptable difficulty level, and 17 (74%) were effective at discriminating between high/low scorers. Nine (61%) had good readability, but comprehension levels ranged from 5 to 18 years. Seven (30%) had elevated 'don't know' responses, highlighting the need for content and construction review. Of the 10 multiple choice items, 9 were complex and not functioning efficiently. Internal consistency was acceptable but could be improved by removing two items. CONCLUSIONS: The response analysis metrics were reviewed by an expert panel and provided a framework for IBD-KID improvements with the aim of increasing discrimination and reducing difficulty without adversely affecting reliability. The proposed revisions will address components that may have caused children to answer incorrectly due to confusion rather than lack of knowledge.

A gene-centric strategy for identifying disease-causing rare variants in dilated cardiomyopathy.

PURPOSE: We evaluated strategies for identifying disease-causing variants in genetic testing for dilated cardiomyopathy (DCM). METHODS: Cardiomyopathy gene panel testing was performed in 532 DCM patients and 527 healthy control subjects. Rare variants in 41 genes were stratified using variant-level and gene-level characteristics. RESULTS: A majority of DCM cases and controls carried rare protein-altering cardiomyopathy gene variants. Variant-level characteristics alone had limited discriminative value. Differentiation between groups was substantially improved by addition of gene-level information that incorporated ranking of genes based on literature evidence for disease association. The odds of DCM were increased to nearly 9-fold for truncating variants or high-impact missense variants in the subset of 14 genes that had the strongest biological links to DCM (P <0.0001). For some of these genes, DCM-associated variants appeared to be clustered in key protein functional domains. Multiple rare variants were present in many family probands, however, there was generally only one "driver" pathogenic variant that cosegregated with disease. CONCLUSION: Rare variants in cardiomyopathy genes can be effectively stratified by combining variant-level and gene-level information. Prioritization of genes based on their a priori likelihood of disease causation is a key factor in identifying clinically actionable variants in cardiac genetic testing.

A Symptom Self-report Tool for Children With Inflammatory Bowel Disease (IBDnow).

OBJECTIVES: Clinical symptom evaluation for children with inflammatory bowel disease (IBD) is typically done using composite tools: the Pediatric Crohn's Disease Activity Index (PCDAI) and Pediatric Ulcerative Colitis Activity Index (PUCAI). Both rely on clinician interpretation of child or parent symptom recall. No universal self-report tool has yet been developed for children with IBD to assess and report their symptoms. The research objective was to develop a self-report tool that produced information congruent with that obtained by clinicians using the PUCAI or PCDAI. METHODS: A children's symptom self-report tool (IBDnow) was developed with picture and text Likert symptom scales. The clinician and child completed their reports during the same outpatient consultation. Agreement levels were calculated at the individual level (identical child and clinician answers), category level (symptom severity), and aggregate level (cohort scores). Internal consistency was measured with Cronbach alpha. RESULTS: One hundred children from Christchurch (New Zealand) (n = 65), and Sydney (Australia) (n = 35) completed the study (Crohn's Disease (CD):88, ulcerative colitis (UC):12), mean age 13.9 years (±3.6). Mean individual agreement was 0.76 (±0.19). Category severity had very good or good inter-rater reliability for 5 of the 7 symptom scales and overall severity agreement of 76%. Aggregate mean scores were significantly different between clinicians (14.9, ±18.8), and participants (21.6, ±19.4), (P <0.005, confidence interval -9.0, -4.4), but 60 pairs had scores within a 10% margin. Cronbach alpha was 0.74. CONCLUSIONS: This self-report tool had good proportionate agreement between raters, and good crude agreement for symptom categories. Assigning PUCAI or PCDAI scores caused inter-rater discrepancies to be misleadingly magnified. Pediatric gastroenterologists may consider utilizing IBDnow to elicit symptom self-reports from children with IBD to enable them to communicate meaningful information on their ongoing symptom burden. This would be a positive step in helping children feel included in clinical encounters and promoting self-management, at the same time producing valid, subjective symptom recall.

Patterns of vitamin D testing and supplementation for children with inflammatory bowel disease in Australasia.

Background and Aim: For children with inflammatory bowel disease (IBD), optimal levels of vitamin D are ascribed anti-inflammatory and essential immune system roles that are associated with reduced disease activity, lower postoperative recurrence, and higher quality of life. International guidelines for vitamin D testing and supplementation provide inconsistent recommendations. The aim of this study was to survey Australasian pediatric gastroenterologists to ascertain current practices of vitamin D testing and supplementation for children with IBD. Methods: Members of the Australian Society of Pediatric Gastroenterology, Hepatology and Nutrition were invited to complete an online survey. Respondents were asked to provide information on frequency of vitamin D testing and supplementation, adherence, and benefits of vitamin D to children with IBD. Results: Thirty-two (54%) pediatric gastroenterologists completed the survey: 27 (84%) from Australia and 5 (16%) from New Zealand. The majority (90%) tested vitamin D levels at diagnosis and follow up, although testing frequency varied (1-3 times/year) and only 8 (28%) tested seasonally. While 28 (88%) recommended supplementation based on serum levels, inconsistent cutoff values were used. Most respondents (n = 27) recommended Stoss (single dose) or vitamin D3 (daily for 8-12 weeks). The majority (84%) rated the overall benefit of optimal vitamin D levels at ≥6/10, although fewer (54%) rated the benefit to disease activity at ≥6/10. Conclusions: The results indicate that standardized guidelines for vitamin D testing and supplementation for clinicians caring for children with IBD throughout Australasia are required. Consensus statements may optimize the care of children with IBD in this diverse geographical region.