Search

Background Population-wide screening for melanoma is not cost-effective, but genetic characterization could facilitate risk stratification and targeted screening. Common Melanocortin-1 receptor (MC1R) red hair colour (RHC) variants and Microphthalmia-associated transcription factor (MITF) E318K separately confer moderate melanoma susceptibility, but their interactive effects are relatively unexplored. Objectives To evaluate whether MC1R genotypes differentially affect melanoma risk in MITF E318K+ vs. E318K– individuals. Materials and methods Melanoma status (affected or unaffected) and genotype data (MC1R and MITF E318K) were collated from research cohorts (five Australian and two European). In addition, RHC genotypes from E318K+ individuals with and without melanoma were extracted from databases (The Cancer Genome Atlas and Medical Genome Research Bank, respectively). χ2 and logistic regression were used to evaluate RHC allele and genotype frequencies within E318K+/– cohorts depending on melanoma status. Replication analysis was conducted on 200 000 general-population exomes (UK Biobank). Results The cohort comprised 1165 MITF E318K– and 322 E318K+ individuals. In E318K– cases MC1R R and r alleles increased melanoma risk relative to wild type (wt), P < 0.001 for both. Similarly, each MC1R RHC genotype (R/R, R/r, R/wt, r/r and r/wt) increased melanoma risk relative to wt/wt (P < 0.001 for all). In E318K+ cases, R alleles increased melanoma risk relative to the wt allele [odds ratio (OR) 2.04 (95% confidence interval 1.67–2.49); P = 0.01], while the r allele risk was comparable with the wt allele [OR 0.78 (0.54–1.14) vs. 1.00, respectively]. E318K+ cases with the r/r genotype had a lower but not significant melanoma risk relative to wt/wt [OR 0.52 (0.20–1.38)]. Within the E318K+ cohort, R genotypes (R/R, R/r and R/wt) conferred a significantly higher risk compared with non-R genotypes (r/r, r/wt and wt/wt) (P < 0.001). UK Biobank data supported our findings that r did not increase melanoma risk in E318K+ individuals. Conclusions RHC alleles/genotypes modify melanoma risk differently in MITF E318K– and E318K+ individuals. Specifically, although all RHC alleles increase risk relative to wt in E318K– individuals, only MC1R R increases melanoma risk in E318K+ individuals. Importantly, in the E318K+ cohort the MC1R r allele risk is comparable with wt. These findings could inform counselling and management for MITF E318K+ individuals.

Systematic literature searches on POT1/POLE/BAP1 found that limited skin phenotypic characteristics have been documented in mutation carriers; 248 variants were annotated, and high-cluster variant regions associated with cutaneous melanoma were found in all three genes. Genotype-phenotype correlations can be used to identify patient disease predisposition based on mutation position and cluster regions.

Oculocutaneous albinism (OCA) is a rare condition characterized by hypopigmentation. A female proband and her sister, both with primary amelanotic/hypopigmented melanoma, underwent three-dimensional total-body photography and dermoscopy. Both sisters had exome sequencing along with their brother, who had OCA but no history of melanoma. Imaging analysis was consistent with OCA in terms of individual typology angle scores, degree of sun damage, and high naevus counts. Exome data filtered for variants in known OCA and melanoma/naevi susceptibility genes (n = 98) found all siblings were compound heterozygous for TYR mutations (Arg402Ter and Val275Phe), previously reported as causative OCA variants. A rare missense variant in PARP1 (p.Pro377Ser) was solely present in the melanoma-unaffected brother, which is noteworthy as this was previously reported as potentially protective in a familial melanoma pedigree positive for CDKN2A mutations. Evaluation and confirmation of functional impact in larger cohorts could personalize melanoma screening in OCA.

Objective: New technologies have afforded increased access to genetic testing providing valuable information for individuals and those biologically related. However, the management of such information is challenging for psychologists given the ethical issues that may arise. This paper aims to review the utility of existing ethical standards and current legislation for psychologists when encountering genetic information. Method: Current legislation and guidelines involved in the management of genetic information applicable for psychologists is critically reviewed in light of relevant ethical principles. Results: While knowledge of information that has arisen from genetic testing may guide psychological therapy, intervention, and education, psychologists have a responsibility to uphold their ethical obligations in order to meet the needs of their clients and their families and to prevent harm. Outside the domain of ethically approved human research, and specific guidance for trained genetic counsellors in Australia, ethical guidance on the management of human genetic information is not readily available for psychologists. Conclusions: Technological advances can be expected to continue to present epistemic dilemmas about the use of genetic material. The implications for future psychological practice is discussed. KEY POINTS What is already known about this topic: (1) Increased access to genetic testing can provide valuable information for individuals and those biologically related. (2) Genetic testing poses new and significant challenges for psychologists, especially in respect to the ethical issues that can occur. (3) Given that findings from genetic testing may guide therapy goals, interventions, and psychoeducation, psychologists have a responsibility to uphold ethical obligations in order to meet the needs of their clients and their families and to prevent harm. Yet, clear guidelines for ethical obligations regarding the handling of genetic testing are not readily available. What this topic adds: (1) Within the framework of current legislation, the four core ethical standards of beneficence, autonomy, justice, and non-maleficence work together with the APS Code of Ethics and ethical guidelines for psychologists. (2) While the use of genetic information has the potential to affect whole communities, it should be used in such a way that maintains ethical principles, meeting the needs of the individual and family. (3) It is important that ethical guidelines for genetic information in the field of psychology remain cohesive to meet the needs of rapid technological advances and changing legislation.

Lung cancer is the commonest cause of cancer deaths worldwide. Although strongly associated with smoking, predisposition to lung cancer is also heritable, with multiple common risk variants identified. Rarely, dominantly inherited non-small-cell lung cancer (NSCLC) has been reported due to somatic mutations in EGFR/ErbB1 and ERBB2. Germline exome sequencing was performed in a multi-generation family with autosomal dominant NSCLC, including an affected child. Tumour samples were also sequenced. Full-length wild-type (wtErbB3) and mutant ERBB3 (mutErbB3) constructs were transfected into HeLa cells. Protein expression, stability, and subcellular localization were assessed, and cellular proliferation, pAkt/Akt and pERK levels determined. A novel germline variant in ERBB3 (c.1946 T > G: p.Iso649Arg), coding for receptor tyrosine-protein kinase erbB-3 (ErbB3), was identified, with appropriate segregation. There was no loss-of-heterozygosity in tumour samples. Both wtErbB3 and mutErbB3 were stably expressed. MutErbB3-transfected cells demonstrated an increased ratio of the 80 kDa form (which enhances proliferation) compared with the full-length (180 kDa) form. MutErbB3 and wtErbB3 had similar punctate cytoplasmic localization pre- and post-epidermal growth factor stimulation; however, epidermal growth factor receptor (EGFR) levels decreased faster post-stimulation in mutErbB3-transfected cells, suggesting more rapid processing of the mutErbB3/EGFR heterodimer. Cellular proliferation was increased in mutErbB3-transfected cells compared with wtErbB3 transfection. MutErbB3-transfected cells also showed decreased pAkt/tAkt ratios and increased pERK/tERK 30 min post-stimulation compared with wtErbB3 transfection, demonstrating altered signalling pathway activation. Cumulatively, these results support this mutation as tumorogenic. This is the first reported family with a germline ERBB3 mutation causing heritable NSCLC, furthering understanding of the ErbB family pathway in oncogenesis.

Background: Although genetic testing for known familial melanoma genes is commercially available, clinical implementation has been restrained as utility is unclear, concerns of causing psychological distress are often cited, and consumer interest and perceptions are not well understood. A review of studies exploring participant-reported psychosocial outcomes and attitudes towards genetic testing for familial melanoma will provide insight into common emotional and cognitive responses. Methods: Database searches of PubMed, Embase, CINAHL, PsycINFO and the Cochrane Library were conducted using a date range of January 1995 to June 2020. Studies examining any psychosocial outcomes alongside genetic testing (real or hypothetical), in participants described as having a high risk of melanoma, were eligible. A narrative synthesis of results was used to describe psychosocial outcomes and summarise participant beliefs and attitudes towards genetic testing. Results: Limited evidence of adverse psychosocial outcomes was found. No impacts on perceived risk or control were reported, and minimal decisional regret was recorded. Generalised distress was comparable between both genetic mutation carriers and non-carriers, often decreasing over time from pretesting levels. Melanoma-specific distress was frequently higher in carriers than non-carriers; however, this difference was present prior to testing and often associated with personal melanoma history. Overall, participants’ attitudes towards testing were largely positive, with benefits more frequently described than limitations, and support for testing minors was strong. Conclusions: This review has found evidence of few adverse psychological outcomes following genetic testing. There was no indication of increased distress after genetic test results had been disclosed. If these findings were replicated in additional, larger, diverse populations over a longer follow-up period, this would be compelling evidence to guide clinical recommendations.

This study aimed to systematically review current models for communicating polygenic scores (PGS) and psycho-behavioral outcomes of receiving PGSs.Original research on communicating PGSs and reporting on psycho-behavioral outcomes was included. Search terms were applied to 5 databases and were limited by date (2009-2021).In total, 28 articles, representing 17 studies in several disease settings were identified. There was limited consistency in PGS communication and evaluation/reporting of outcomes. Most studies (n = 14) presented risk in multiple ways (ie, numerically, verbally, and/or visually). Three studies provided personalized lifestyle advice and additional resources. Only 1 of 17 studies reported using behavior change theory to inform their PGS intervention. A total of 8 studies found no evidence of long-term negative psychosocial effects up to 12 months post result. Of 14 studies reporting on behavior, 9 found at least 1 favorable change after PGS receipt. When stratified by risk, 7 out of 9 studies found high PGS was associated with favorable changes including lifestyle, medication, and screening. Low-risk PGS was not associated with maladaptive behaviors (n = 4).PGS has the potential to benefit health behavior. High variability among studies emphasizes the need for developing standardized guidelines for communicating PGSs and evaluating psycho-behavioral outcomes. Our findings call for development of best communication practices and evidence-based interventions informed by behavior change theories.

Background Clinical whole exome sequencing was introduced in an Australian centre in 2017, as an alternative to Sanger sequencing. We aimed to identify predictors of cancer physicians’ somatic mutation test ordering behaviour. Methods A validated instrument assessed somatic mutation test ordering, genomic confidence, perceived utility of tumour molecular profiling, and percent of patients eligible for targeted therapy. A cash incentive was included in 189/244 questionnaires which were mailed to all Queensland cancer specialists in November 2018. Results 110 participated (response rate 45%); 54.7% oncologists, and the remainder were surgeons, haematologists and pulmonologists. Oncologists were more likely to respond (p = 0.008), and cash incentive improved the response rate (p Conclusions Consistent with previous studies, the majority of cancer physicians ordered somatic mutation tests. However, the percentage of patients on whom tests were ordered was low. Almost half respondents reported low genomic confidence. Somatic mutation test ordering was higher amongst oncologists and those with increased confidence in interpreting somatic variants. It is unclear whether genomically confident individuals ordered more tests or whether ordering more tests increased genomic confidence. Educational interventions could improve confidence and enhance test ordering behaviour.

The journey to receiving a diagnosis for rare genetic disease can be long and emotionally impactful. This study describes parental experiences of receiving their child's diagnosis of Rubinstein-Taybi syndrome (RTS), a rare genetic condition characterized by growth and developmental delay together with dysmorphic features. Parents from the RTS Australia support group participated in qualitative, semi-structured phone interviews, which were transcribed verbatim and thematically analyzed. Questions focused on psychosocial challenges and benefits pre and post-diagnosis. Ten mothers and three fathers participated, with the mean age of diagnosis being 8 months. Parents reported positive psychological effects from a slight delay in diagnosis, and negative effects from an extended diagnostic delay, suggesting the ideal time for a parent to receive a diagnosis lies in the post attachment stage, prior to the development of significant parental concerns. This stage would vary depending on condition severity. Parents desired a diagnosis to reduce uncertainty; however, uncertainty remained post diagnosis, and shifted its focus from broadly encompassing etiology and prognosis, to specifically focusing on concerns regarding severity within the spectrum. Perceived benefits of a diagnosis mainly centered on the provision of a label. Parents articulated that a label increased social acceptance, enhanced coping, promoted communication, and improved access to medical, financial, and support services. This study provides insights into the experience of families prior to and following receipt of a diagnosis. It also highlights the possibility of an optimal time window to receive a diagnosis; in which bonding is maximized and parental distress is minimized.

Genetic testing is used widely for diagnostic, carrier and predictive testing in monogenic diseases. Until recently, there were no genetic testing options available for multifactorial complex diseases like heart disease, diabetes and cancer. Genome-wide association studies (GWAS) have been invaluable in identifying single-nucleotide polymorphisms (SNPs) associated with increased or decreased risk for hundreds of complex disorders. For a given disease, SNPs can be combined to generate a cumulative estimation of risk known as a polygenic risk score (PRS). After years of research, PRSs are increasingly used in clinical settings. In this article, we will review the literature on how both genome-wide and restricted PRSs are developed and the relative merit of each. The validation and evaluation of PRSs will also be discussed, including the recognition that PRS validity is intrinsically linked to the methodological and analytical approach of the foundation GWAS together with the ethnic characteristics of that cohort. Specifically, population differences may affect imputation accuracy, risk magnitude and direction. Even as PRSs are being introduced into clinical practice, there is a push to combine them with clinical and demographic risk factors to develop a holistic disease risk. The existing evidence regarding the clinical utility of PRSs is considered across four different domains: informing population screening programs, guiding therapeutic interventions, refining risk for families at high risk, and facilitating diagnosis and predicting prognostic outcomes. The evidence for clinical utility in relation to five well-studied disorders is summarized. The potential ethical, legal and social implications are also highlighted.

Skin phenotype, host genotype and ultraviolet (UV) damage play a role in the development of melanoma.To ascertain whether the level of UV damage at the site of melanomas was associated with genetic polymorphisms.Deep phenotyping was performed on 1244 individuals; 281 with multiple primary melanomas (MPMs), 304 with single primary melanoma (SPM) and 659 convenience controls. Genotype data was generated using the Illumina CoreExome microarray platform, assaying over 500 000 single-nucleotide polymorphisms. A subset of variants were combined to assess a polygenic risk score (PRS) for melanoma.Most MPM cases were diagnosed in patients aged40 years, in sites with visible chronic UV damage. Women and those diagnosed at age ≤ 40 years were less likely to have perilesional UV damage. Patients with MPM had higher frequencies of MITF E318K, MC1R R-alleles and the ASIP risk haplotype. Individuals who had melanoma in a visibly UV-damaged site were more likely to carry MC1R rs75570604 [odds ratio (OR) 2·5], 9q31.2 rs10816595 (OR 1·4) and MTAP rs869329 (OR 1·4). These same alleles were more common in patients with MPM who were diagnosed at age ≤ 40 years. The mean PRS was significantly higher in MPM than in SPM and controls. Naevus count was comparable in early-onset MPM cases and those diagnosed at age40 years.Our cohort demonstrated higher frequencies of previously reported alleles associated with melanoma. MPM melanomas more commonly occur in UV-damaged areas, and these individuals are more likely to carry MC1R red hair colour alleles. Awareness of the interplay of genetic vulnerability with UV damage can stratify risk and guide recommendations for melanoma screening. What's already known about this topic? Skin phenotype, host genotype and ultraviolet (UV) damage all play a role in melanoma development. One of the main risk factors is a personal history of melanoma; second and subsequent primary melanomas account for over 20% of all melanomas registered in Queensland. Multiple loci are associated with melanoma risk, including many low-penetrance loci, which may have a cumulatively significant risk. Population-wide screening programmes for melanoma are not yet economically viable. What does this study add? Patients diagnosed with melanoma at age ≤ 40 years were more likely than older patients to have melanomas in non-UV-damaged sites. Patients with multiple melanomas had higher frequencies of MITF E318K, MC1R R-alleles, and the ASIP extended risk haplotype than patients with single melanoma. CDKN2A, MC1R and MTAP variants were more frequent in patients who developed melanomas at a younger age, but also in those whose melanomas were all on visibly UV-damaged sites. What is the translational message? Incorporating these genetic findings into the known risk factors of skin phenotype and visible UV damage may allow for a more customized and economically feasible approach to early detection of melanoma, particularly in younger patients. Plain language summary available online.

Marfan syndrome (MFS) is an autosomal dominantly inherited connective tissue disorder. Aortic dilatation/dissection and ectopia lentis are the most severe features, which affect physical functioning and psychological well-being. In Aboriginal Australians, there is little psychosocial research on genetic conditions. This study explored the physical, psychological, and practical impacts of MFS on Aboriginal Australians. Eighteen (8 affected and 10 unaffected) members of a large Aboriginal Australian family with MFS participated in an ethically approved study. Semi-structured qualitative interviews were conducted, transcribed verbatim, and analyzed thematically. All individuals reported challenges from MFS, negatively affecting day-to-day living. Severe vision impairment was perceived as the greatest challenge, contributing to feelings of stigma and exclusion. With aging, concerns shifted toward cardiac complications. The unpredictability of lens dislocation and aortic dissection was reported to be psychologically challenging. Participants described MFS-related barriers to obtaining and retaining employment, especially following cardiac surgery; with consequential psychological and financial hardships. Participants articulated that their cultural drive to support the ill and respectfully mourn the deceased, regardless of distance, resulted in a significant financial burden. Additionally, when hospitalization and/or funerals occurred, financially solvent individuals were expected to share resources, without any expectation of repayment or reciprocity (i.e., 'demand sharing', common in Aboriginal Australian culture). This study documents the nature and pervasiveness of uncertainty for both affected and unaffected members of an MFS family. Many reported challenges are consistent with other MFS cohorts (including stigma, social exclusion, and unemployment). However, our findings suggest that cultural values may exacerbate the financial costs of MFS for Aboriginal Australians.

Maturity-onset diabetes of the young (MODY) is a heterogeneous group of monogenic disorders of impaired pancreatic β cell function. The mechanisms underlying MODY include β cell KATP channel dysfunction (e.g., KCNJ11 [MODY13] or ABCC8 [MODY12] mutations); however, no other β cell channelopathies have been associated with MODY to date. Here, we have identified a nonsynonymous coding variant in KCNK16 (NM_001135105: c.341T>C, p.Leu114Pro) segregating with MODY. KCNK16 is the most abundant and β cell–restricted K+ channel transcript, encoding the two-pore-domain K+ channel TALK-1. Whole-cell K+ currents demonstrated a large gain of function with TALK-1 Leu114Pro compared with TALK-1 WT, due to greater single-channel activity. Glucose-stimulated membrane potential depolarization and Ca2+ influx were inhibited in mouse islets expressing TALK-1 Leu114Pro with less endoplasmic reticulum Ca2+ storage. TALK-1 Leu114Pro significantly blunted glucose-stimulated insulin secretion compared with TALK-1 WT in mouse and human islets. These data suggest that KCNK16 is a previously unreported gene for MODY.

BackgroundThe use of genetic test results in risk-rated insurance is a significant concern internationally, with many countries banning or restricting the use of genetic test results in underwriting. In Australia, life insurers’ use of genetic test results is legal and self-regulated by the insurance industry (Financial Services Council (FSC)). In 2018, an Australian Parliamentary Inquiry recommended that insurers’ use of genetic test results in underwriting should be prohibited. In 2019, the FSC introduced an industry self-regulated moratorium on the use of genetic test results. In the absence of government oversight, it is critical that the impact, effectiveness and appropriateness of the moratorium is monitored. Here we describe the protocol of our government-funded research project, which will serve that critical function between 2020 and 2023.MethodsA realist evaluation framework was developed for the project, using a context-mechanism-outcome (CMO) approach, to systematically assess the impact of the moratorium for a range of stakeholders. Outcomes which need to be achieved for the moratorium to accomplish its intended aims were identified, and specific data collection measures methods were developed to gather the evidence from relevant stakeholder groups (consumers, health professionals, financial industry and genetic research community) to determine if aims are achieved. Results from each arm of the study will be analysed and published in peer-reviewed journals as they become available.DiscussionThe A-GLIMMER project will provide essential monitoring of the impact and effectiveness of the self-regulated insurance moratorium. On completion of the study (3 years) a Stakeholder Report will be compiled. The Stakeholder Report will synthesise the evidence gathered in each arm of the study and use the CMO framework to evaluate the extent to which each of the outcomes have been achieved, and make evidence-based recommendations to the Australian federal government, life insurance industry and other stakeholders.

Background: Cherry angiomas are common benign vascular skin lesions of unknown aetiology, found largely on the trunk. However, their exact anatomic distribution besides their truncal predisposition, and how they manifest in the general population, has not been characterised. Methods: Three-dimensional (3D) total body imaging was obtained from 163 adult participants of a general population cohort study in Brisbane, Australia. Demographic, phenotypic, and sun behaviour characteristics were collected using a standard questionnaire along with history of melanoma and keratinocyte cancers. Cherry angiomas were identified using an automated classification algorithm with a sensitivity of 87% and a specificity of 99%, developed specifically for this study population. Results: The 3D total body images of 163 participants were analysed. Participants had a median age of 57 years and 61% were male. On average, males had more angiomas than females (median of 16 vs. 12) and the number and size of cherry angiomas increased with age. In addition to male sex and age, an increase in angiomas was associated with Caucasian ancestry other than British/Irish only, fair skin colour opposed to medium/olive, having green/hazel eyes compared to blue/grey, and personal history of melanoma. The most common site for cherry angiomas was the front trunk, followed by the back. Interestingly, although males had more angiomas overall, females had more angiomas on the legs. Conclusion: Describing the distribution of cherry angiomas by body site is an important step towards further understanding of the aetiology of angiomas. While personal history of melanoma is associated with an increased number of cherry angiomas, whether this association is prognostic, co-occurs with development of melanoma, or is merely fortuitous requires further investigation.

The genetic causes of multiple congenital anomalies are incompletely understood. Here, we report novel heterozygous predicted loss-of-function (LoF) and predicted damaging missense variants in the WW domain binding protein 11 (WBP11) gene in seven unrelated families with a variety of overlapping congenital malformations, including cardiac, vertebral, tracheo-esophageal, renal and limb defects. WBP11 encodes a component of the spliceosome with the ability to activate pre-messenger RNA splicing. We generated a Wbp11 null allele in mouse using CRISPR-Cas9 targeting. Wbp11 homozygous null embryos die prior to E8.5, indicating that Wbp11 is essential for development. Fewer Wbp11 heterozygous null mice are found than expected due to embryonic and postnatal death. Importantly, Wbp11 heterozygous null mice are small and exhibit defects in axial skeleton, kidneys and esophagus, similar to the affected individuals, supporting the role of WBP11 haploinsufficiency in the development of congenital malformations in humans. LoF WBP11 variants should be considered as a possible cause of VACTERL association as well as isolated Klippel-Feil syndrome, renal agenesis or esophageal atresia.

Background Recent genome-wide association meta-analysis for melanoma doubled the number of previously identified variants. We assessed the performance of an updated polygenic risk score (PRS) in a population of older individuals, where melanoma incidence and cumulative ultraviolet radiation exposure is greatest. Methods We assessed a PRS for cutaneous melanoma comprising 55 variants in a prospective study of 12 712 individuals in the ASPirin in Reducing Events in the Elderly Trial. We evaluated incident melanomas diagnosed during the trial and prevalent melanomas diagnosed preenrolment (self-reported). Multivariable models examined associations between PRS as a continuous variable (per SD) and categorical (low-risk [0%-20%], medium-risk [21%-80%], high-risk [81%-100%] groups) with incident melanoma. Logistic regression examined the association between PRS and prevalent melanoma. Results At baseline, mean participant age was 75 years; 55.0% were female, and 528 (4.2%) had prevalent melanomas. During follow-up (median = 4.7 years), 120 (1.0%) incident cutaneous melanomas occurred, 98 of which were in participants with no history. PRS was associated with incident melanoma (hazard ratio = 1.46 per SD, 95% confidence interval [CI] = 1.20 to 1.77) and prevalent melanoma (odds ratio [OR] = 1.55 per SD, 95% CI = 1.42 to 1.69). Participants in the highest-risk PRS group had increased risk compared with the low-risk group for incident melanoma (OR = 2.51, 95% CI = 1.28 to 4.92) and prevalent melanoma (OR = 3.66, 95% CI = 2.69 to 5.05). When stratifying by sex, only males had an association between the PRS and incident melanoma, whereas both sexes had an association between the PRS and prevalent melanoma. Conclusions A genomic risk score is associated with melanoma risk in older individuals and may contribute to targeted surveillance.

Context Pathogenic germline MAX variants are associated with pheochromocytoma and paraganglioma (PPGL), pituitary neuroendocrine tumors and, possibly, other endocrine and nonendocrine tumors. Objective To report 2 families with germline MAX variants, pheochromocytomas (PCs) and multiple other tumors. Methods Clinical, genetic, immunohistochemical, and functional studies at University hospitals in Australia on 2 families with germline MAX variants undergoing usual clinical care. The main outcome measures were phenotyping; germline and tumor sequencing; immunohistochemistry of PC and other tumors; functional studies of MAX variants. Results Family A has multiple individuals with PC (including bilateral and metastatic disease) and 2 children (to date, without PC) with neuroendocrine tumors (paravertebral ganglioneuroma and abdominal neuroblastoma, respectively). One individual has acromegaly; immunohistochemistry of PC tissue showed positive growth hormone–releasing hormone staining. Another individual with previously resected PCs has pituitary enlargement and elevated insulin-like growth factor (IGF-1). A germline MAX variant (c.200C>A, p.Ala67Asp) was identified in all individuals with PC and both children, with loss of heterozygosity in PC tissue. Immunohistochemistry showed loss of MAX staining in PCs and other neural crest tumors. In vitro studies confirmed the variant as loss of function. In Family B, the proband has bilateral and metastatic PC, prolactin-producing pituitary tumor, multigland parathyroid adenomas, chondrosarcoma, and multifocal pulmonary adenocarcinomas. A truncating germline MAX variant (c.22G>T, p.Glu8*) was identified. Conclusion Germline MAX mutations are associated with PCs, ganglioneuromas, neuroblastomas, pituitary neuroendocrine tumors, and, possibly, parathyroid adenomas, as well as nonendocrine tumors of chondrosarcoma and lung adenocarcinoma, suggesting MAX is a novel multiple endocrine neoplasia gene.

Background: Increasing availability of panel testing for known high-penetrance familial melanoma genes has made it possible to improve risk awareness in those at greatest risk. Prior to wider implementation, the role of genetic testing in preventing melanoma, through influencing primary and secondary preventative behaviours, requires clarification. Methods: Database searches of PubMed, Embase, CINAHL, PsycINFO and the Cochrane Library were conducted for studies describing preventative behaviour outcomes in response to genetic testing for melanoma risk. Publications describing original research of any study type were screened for eligibility. Results: Eighteen publications describing 11 unique studies were reviewed. Outcomes assessed are based on health behaviour recommendations for those at increased risk: adherence to sun-protective behaviour (SPB); clinical skin examinations (CSE); skin self-examinations (SSE); and family discussion of risk. Overall, modest increases in adherence to primary prevention strategies of SPB were observed following genetic testing. Importantly, there were no net decreases in SPB found amongst non-carriers. For secondary preventative behaviour outcomes, including CSE and SSE, increases in post-test intentions and long-term adherence were reported across several subgroups in approximately half of the studies. While this increase reached significance in mutation carriers in some studies, one study reported a significant decline in annual CSE adherence of non-mutation carriers. Conclusions: Evidence reviewed suggests that genetic testing has a modestly positive impact on preventative behaviour in high-risk individuals. Furthermore, improvements are observed regardless of mutation carrier status, although greater adherence is found in carriers. While additional studies of more diverse cohorts would be needed to inform clinical recommendations, the findings are encouraging and suggest that genetic testing for melanoma has a positive impact on preventative behaviours.

Objective To describe the communication of polygenic risk scores (PRS) in the familial breast cancer setting. Methods Consultations between genetic healthcare providers (GHP) and female patients who received their PRS for breast cancer risk were recorded (n = 65). GHPs included genetic counselors (n = 8) and medical practitioners (n = 5) (i.e. clinical geneticists and oncologists). A content analysis was conducted and logistic regression was used to assess differences in communication behaviors between genetic counselors (n = 8) and medical practitioners (n = 5). Results Of the 65 patients, 31 (47.7 %) had a personal history of breast cancer, 18 of whom received an increased PRS (relative risk >1.2). 25/34 unaffected patients received an increased PRS. Consultations were primarily clinician-driven and focused on biomedical information. There was little difference between the biomedical information provided by genetic counselors and medical practitioners. However, genetic counselors were significantly more likely to utilize strategies to build patient rapport and counseling techniques. Conclusions Our findings provide one of the earliest reports on how breast cancer PRSs are communicated to women. Practice implications Key messages for communicating PRSs were identified, namely: discussing differences between polygenic and monogenic testing, the multifactorial nature of breast cancer risk, polygenic inheritance and current limitation of PRSs.

1-5% of individuals with melanoma have a strong family history with a causal gene identified in ~30% of those families, most commonly CDKN2A. Genetic testing and counselling for CDKN2A improves sun-protective and surveillance behaviour without negative psychological sequelae. Given these advantages, dermatologists need to recognise those with a sufficient a priori risk to warrant the offer of genetic testing.

BackgroundLung cancer is the commonest cause of cancer deaths worldwide. Although strongly associated with smoking, predisposition to lung cancer is also heritable with multiple common risk variants identified. Rarely, dominantly inherited non-small-cell lung cancer (NSCLC) has been reported due to somatic mutations in EGFR/ErbB1 and ERBB2.MethodsGermline exome sequencing was performed in a multi-generation family with autosomal dominant NSCLC, including an affected child. Tumour samples were also sequenced. Full-length wild-type (wtErbB3) and mutant ERBB3 (mutErbB3) constructs were transfected into HeLa cells. Protein expression, stability, and sub-cellular localisation were assessed; and cellular proliferation, pAkt/Akt, and pERK levels were determined.ResultsA novel germline variant in ERBB3 (c.1946T>G: p.Iso649Arg), coding for receptor tyrosineprotein kinase erbB-3 (ErbB3), was identified, with appropriate segregation. There was no loss-of-heterozygosity in tumour samples. Both wtErbB3 and mutErbB3 were stably expressed. MutErbB3-transfected cells demonstrated an increased ratio of the 80kD form (which enhances proliferation) compared to the full-length (180kD) form. MutErbB3 and wtErbB3 had similar punctate cytoplasmic localisation pre- and post-EGF stimulation; however, EGFR levels decreased faster post-stimulation in mutErbB3-transfected cells, suggesting more rapid processing of the mutErbB3/EGFR heterodimer. Cellular proliferation was increased in mutErbB3-transfected cells compared to wtErbB3 transfection. MutErbB3-transfected cells also showed decreased pAkt/tAkt ratios and increased pERK/tERK 30 minutes post-stimulation compared to wtErbB3 transfection, demonstrating altered signalling pathway activation by mutErbB3. Cumulatively, these results support this mutation as tumorogenic.ConclusionsThis is the first reported family with a germline ERBB3 mutation causing heritable NSCLC, furthering understanding of the ErbB family pathway in oncogenesis.

Causal attributions are important determinants of how health threats are processed and affect health-related behaviors. To date, there has been no research on causal attributions in genetic conditions in Aboriginal Australians. Forty members of a large Aboriginal Australian family with Marfan syndrome (MFS) were invited to participate in an ethically approved study exploring causal attributions, including perceived causes of phenotypic variability within the family. Eighteen individuals consented to conduct semi-structured qualitative interviews, which were recorded, transcribed verbatim and analyzed thematically. Most participants knew that MFS was genetic, but there were diverse theories about inheritance, including beliefs that it skipped generations, was affected by birth order and/or gender, and that it co-occurred with inheritance of blue eyes within this family. The mutation was thought to have been inherited from British settlers and initially triggered by disease or diet. Factors believed to modify disease severity included other genes and lifestyle factors, particularly alcohol and substance abuse and stress. Generally, this family did not endorse “blaming” chance or a higher power for phenotypic variability, though some felt that the spirits or a deity may have played a role. In conclusion, although participants knew MFS was a genetic condition, many speculated about the role of non-genetic causes in initiating the original mutation; and the gene-environment interaction was thought to affect severity. This study demonstrates a successful approach for exploring causal attributions in other genetic conditions in First Australians.

Background Marfan syndrome (MFS) is a dominant monogenic disorder caused by mutations in fibrillin 1 (FBN1). Rarely, compound heterozygosity for FBN1 mutations has been described. Methods A large kindred with MFS was assessed clinically over decades, and genetically using exome and/or Sanger sequencing. Results A previously identified FBN1 missense variant (p.Tyr754Cys) was confirmed in all subjects with MFS. An additional variant (p.Met2273Thr), previously associated with incomplete MFS, was identified in three siblings. These three compound heterozygous individuals had aortic dilatation at early age (all 40 years but not requiring surgical intervention. Another heterozygous (p.Tyr754Cys) sibling did require aortic root repair (28 years). The heterozygous (p.Met2273Thr) mother had aortic dilatation diagnosed at age 68 years but has not required surgical repair. Conclusion Although compound heterozygosity or homozygosity is rare in MFS, it should be considered when there is an unusually severe phenotype in a subset of family members., Marfan syndrome (MFS) is a dominant monogenic disorder caused by mutations in FBN1. Compound heterozygous mutations in FBN1 were identified in a large family with Marfan syndrome. Although compound heterozygosity or homozygosity is rare in MFS, it should be considered when there is an unusually severe phenotype in a subset of family members.

BackgroundMaturity-onset diabetes of the young (MODY) is a heterogeneous group of monogenic disorders of impaired glucose-stimulated insulin secretion (GSIS). Mechanisms include β-cell KATPchannel dysfunction (e.g.,KCNJ11(MODY13) orABCC8(MODY12) mutations); however, no other β-cell channelopathies have been identified in MODY.MethodsA four-generation family with autosomal dominant non-obese, non-ketotic antibody-negative diabetes, without mutations in known MODY genes, underwent exome sequencing. Whole-cell and single-channel K+currents, Ca2+handling, and GSIS were determined in cells expressing either mutated or wild-type (WT) protein.ResultsWe identified a novel non-synonymous genetic mutation inKCNK16(NM_001135105: c.341T>C, p.Leu114Pro) segregating with MODY.KCNK16is the most abundant and β-cell-restricted K+channel transcript and encodes the two-pore-domain K+channel TALK-1. Whole-cell K+currents in transfected HEK293 cells demonstrated drastic (312-fold increase) gain-of-function with TALK-1 Leu144Pro vs. WT, due to greater single channel activity. Glucose-stimulated cytosolic Ca2+influx was inhibited in mouse islets expressing TALK-1 Leu114Pro (area under the curve [AUC] at 20mM glucose: Leu114Pro 60.1 vs. WT 89.1;P=0.030) and less endoplasmic reticulum calcium storage (cyclopiazonic acid-induced release AUC: Leu114Pro 17.5 vs. WT 46.8;P=0.008). TALK-1 Leu114Pro significantly blunted GSIS compared to TALK-1 WT in both mouse (52% decrease,P=0.039) and human (38% decrease,P=0.019) islets.ConclusionsOur data identify a novel MODY-associated gene,KCNK16; with a gain-of-function mutation limiting Ca2+influx and GSIS. A gain-of-function common polymorphism inKCNK16is associated with type 2 diabetes (T2DM); thus, our findings have therapeutic implications not only forKCNK16-associated MODY but also for T2DM.

Osteogenesis imperfecta (OI) is a genetic bone disorder characterized by fractures, low bone mass, and skeletal fragility. It most commonly arises from dominantly inherited mutations in the genes COL1A1 and COL1A2 that encode the chains of type I collagen. A number of recent reports have suggested that mutations affecting the carboxyl-terminal propeptide cleavage site in the products of either COL1A1 or COL1A2 give rise to a form of OI characterized by unusually dense bones. We have assembled clinical, biochemical, and molecular data from 29 individuals from 8 families with 7 different mutations affecting the C-propeptide cleavage site. The phenotype was generally mild: The median height was ∼33th centile. Eighty percent of subjects had their first fracture by the age of 10 years, and one-third had a femoral or tibial fracture by the age of 25 years. Fractures continued into adulthood, though rates varied considerably. Healing was normal and rarely resulted in long bone deformity. One-third of subjects older than 15 years had scoliosis. The teeth and hearing were normal in most, and blue sclerae were not observed. Other features noted included fibro-osseous dysplasia of the mandible and Achilles tendon calcification. The mean spinal bone mineral density Z-score was +2.9 (SD 2.1) compared with -2.2 (0.7) in subjects with COL1A1 haploinsufficiency mutations. Bone mineral density distribution, assessed by quantitative backscattered electron imaging in bone showed higher levels of mineralization than found in any other disorder. Bone histology showed high trabecular volume and increased cortical thickness, with hyperosteoidosis and delayed mineralization. In vitro studies with cultured skin fibroblasts suggested that these mutations interfere with processing of the chain in which the sequence alteration occurs, but the C-propeptide is eventually cleaved (and detectable in blood), suggesting there are alternative sites of cleavage. The precise mechanism of the bony pathology is not yet clear. © 2018 American Society for Bone and Mineral Research.

We previously reported exome sequencing in a short-rib thoracic dystrophy (SRTD) cohort, in whom recessive mutations were identified in SRTD-associated genes in 10 of 11 cases. A heterozygous stop mutation in the known SRTD gene WDR60 was identified in the remaining case; no novel candidate gene/s were suggested by homozygous/compound heterozygous analysis. This case was thus considered unsolved. Re-analysis following an analysis pipeline update identified a homozygous mutation in C21orf2 (c.218G > C; p.Arg73Pro). This homozygous variant was previously removed at the quality control stage by the default GATK parameter “in-breeding co-efficient.” C21orf2 was recently associated with both Jeune asphyxiating thoracic dystrophy (JATD) and axial spondylometaphyseal dysplasia (axial SMD); this particular mutation was reported in homozygous and compound heterozygous state in both conditions. Our case has phenotypic features of both JATD and axial SMD; and the extent of thoracic involvement appears more severe than in other C21orf2-positive cases. Identification of a homozygous C21orf2 mutation in this case emphasizes the value of exome sequencing for simultaneously screening known genes and identifying novel genes. Additionally, it highlights the importance of re-interrogating data both as novel gene associations are identified and as analysis pipelines are refined. Finally, the severity of thoracic restriction in this case adds to the phenotypic spectrum attributable to C21orf2 mutations.

Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes. Exome sequencing of a non-obese four-generation family with autosomal dominant non-ketotic antibody-negative diabetes, who were negative for mutations in known MODY genes, identified a novel coding variant in KCNK16 (NM_001135105: c.341T>C, p.Leu114Pro) affecting a highly conserved base and predicted to be damaging. KCNK16 encodes TALK-1, a pancreatic β-cell potassium channel which modulates β-cell excitability, controlling Ca2+ influx and insulin secretion. Activation of TALK-1 reduces insulin secretion. A coding gain-of-function variant in KCNK16 is associated with type 2 diabetes in multi-ethnic genome-wide association studies. Notably, TALK-1 is not sensitive to sulfonylureas. HEK-293 cells were transfected with either wild-type or Leu114Pro TALK-1 constructs using a CMV promoter and including P2A mCherry to enable confirmation of successful transfection. Whole cell cross-membrane voltage clamping, with voltage ramped from -120mV to 60mV, demonstrated a drastic increase in current with mutant TALK-1 compared to wild-type, consistent with marked gain-of-function and likely to reduce insulin secretion. Our data suggest that KCNK16 may be a novel MODY gene. If confirmed, this has therapeutic implications not only for these individuals but potentially for novel management of type 2 diabetes. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Frontometaphyseal dysplasia (FMD) is a progressive sclerosing skeletal dysplasia affecting the long bones and skull. The cause of FMD in some individuals is gain-of-function mutations in FLNA, although how these mutations result in a hyperostotic phenotype remains unknown. Approximately one half of individuals with FMD have no identified mutation in FLNA and are phenotypically very similar to individuals with FLNA mutations, except for an increased tendency to form keloid scars. Using whole-exome sequencing and targeted Sanger sequencing in 19 FMD-affected individuals with no identifiable FLNA mutation, we identified mutations in two genes-MAP3K7, encoding transforming growth factor β (TGF-β)-activated kinase (TAK1), and TAB2, encoding TAK1-associated binding protein 2 (TAB2). Four mutations were found in MAP3K7, including one highly recurrent (n = 15) de novo mutation (c.1454C>T [ p.Pro485Leu]) proximal to the coiled-coil domain of TAK1 and three missense mutations affecting the kinase domain (c.208G>C [p.Glu70Gln], c.299T>A [p.Val100Glu], and c.502G>C [p.Gly168Arg]). Notably, the subjects with the latter three mutations had a milder FMD phenotype. An additional de novo mutation was found in TAB2 (c.1705G>A, p.Glu569Lys). The recurrent mutation does not destabilize TAK1, or impair its ability to homodimerize or bind TAB2, but it does increase TAK1 autophosphorylation and alter the activity of more than one signaling pathway regulated by the TAK1 kinase complex. These findings show that dysregulation of the TAK1 complex produces a close phenocopy of FMD caused by FLNA mutations. Furthermore, they suggest that the pathogenesis of some of the filaminopathies caused by FLNA mutations might be mediated by misregulation of signaling coordinated through the TAK1 signaling complex.

Fryns syndrome is an autosomal recessive condition characterized by congenital diaphragmatic hernia (CDH), dysmorphic facial features, distal digital hypoplasia, and other associated malformations, and is the most common syndromic form of CDH. No gene has been associated with this condition. Whole-exome sequence data from two siblings and three unrelated individuals with Fryns syndrome were filtered for rare, good quality, coding mutations fitting a recessive inheritance model. Compound heterozygous mutations in PIGN were identified in the siblings, with appropriate parental segregation: a novel STOP mutation (c.1966CT: p.Glu656X) and a rare (minor allele frequency0.001) donor splice site mutation (c.1674+1GC) causing skipping of exon 18 and utilization of a cryptic acceptor site in exon 19. A further novel homozygous STOP mutation in PIGN (c.694AT: p.Lys232X) was detected in one unrelated case. All three variants affected highly conserved bases. The two remaining cases were negative for PIGN mutations. Mutations in PIGN have been reported in cases with multiple congenital anomalies, including one case with syndromic CDH. Fryns syndrome can be caused by recessive mutations in PIGN. Whether PIGN affects other syndromic and non-syndromic forms of CDH warrants investigation.

Background Acromelic dysplasias are a group of disorders characterised by short stature, brachydactyly, limited joint extension and thickened skin and comprises acromicric dysplasia (AD), geleophysic dysplasia (GD), Myhre syndrome and Weill–Marchesani syndrome. Mutations in several genes have been identified for these disorders (including latent transforming growth factor β (TGF-β)-binding protein-2 (LTBP2), ADAMTS10, ADAMSTS17 and fibrillin-1 (FBN1) for Weill–Marchesani syndrome, ADAMTSL2 for recessive GD and FBN1 for AD and dominant GD), encoding proteins involved in the microfibrillar network. However, not all cases have mutations in these genes. Methods Individuals negative for mutations in known acromelic dysplasia genes underwent whole exome sequencing. Results A heterozygous missense mutation (exon 14: c.2087C>G: p.Ser696Cys) in latent transforming growth factor β (TGF-β)-binding protein-3 (LTBP3) was identified in a dominant AD family. Two distinct de novo heterozygous LTPB3 mutations were also identified in two unrelated GD individuals who had died in early childhood from respiratory failure–a donor splice site mutation (exon 12 c.1846+5G>A) and a stop-loss mutation (exon 28: c.3912A>T: p.1304*Cysext*12). Conclusions The constellation of features in these AD and GD cases, including postnatal growth retardation of long bones and lung involvement, is reminiscent of the null ltbp3 mice phenotype. We conclude that LTBP3 is a novel component of the microfibrillar network involved in the acromelic dysplasia spectrum.

Amelanotic/hypomelanotic melanoma is a clinicopathologic subtype with absent or minimal melanin. This study assessed previously reported coding variants in albinism genes (TYR, OCA2, TYRP1, SLC45A2, SLC24A5, LRMDA) and common intronic, regulatory variants of OCA2 in individuals with amelanotic/hypomelanotic melanoma, pigmented melanoma cases and controls. Exome sequencing was available for 28 individuals with amelanotic/hypomelanotic melanoma and 303 individuals with pigmented melanoma, which were compared to whole exome data from 1144 Australian controls. Microarray genotyping was available for a further 17 amelanotic/hypomelanotic melanoma, 86 pigmented melanoma, 147 melanoma cases (pigmentation unknown) and 652 unaffected controls. Rare deleterious variants in TYR/OCA1 were more common in amelanotic/hypomelanotic melanoma cases than pigmented melanoma cases (set mixed model association tests P = 0.0088). The OCA2 hypomorphic allele p.V443I was more common in melanoma cases (1.8%) than controls (1.0%, X2 P = 0.02), and more so in amelanotic/hypomelanotic melanoma (4.4%, X2 P = 0.007). No amelanotic/hypomelanotic melanoma cases carried an eye and skin darkening haplotype of OCA2 (including rs7174027), present in 7.1% of pigmented melanoma cases (P = 0.0005) and 9.4% controls. Variants in TYR and OCA2 may play a role in amelanotic/hypomelanotic melanoma susceptibility. We suggest that somatic loss of function at these loci could contribute to the loss of tumor pigmentation, consistent with this we found a higher rate of somatic mutation in TYR/OCA2 in amelanotic/hypomelanotic melanoma vs pigmented melanoma samples (28.6% vs 3.0%; P = 0.021) from The Cancer Genome Atlas Skin Cutaneous Melanoma collection.

Osteogenesis imperfecta (OI) is a genetic bone disorder characterized by fractures, low bone mass, and skeletal fragility. It most commonly arises from dominantly inherited mutations in the genes COL1A1 and COL1A2 that encode the chains of type I collagen. A number of recent reports have suggested that mutations affecting the carboxyl-terminal propeptide cleavage site in the products of either COL1A1 or COL1A2 give rise to a form of OI characterized by unusually dense bones. We have assembled clinical, biochemical, and molecular data from 29 individuals from 8 families with 7 different mutations affecting the C-propeptide cleavage site. The phenotype was generally mild: The median height was ∼33th centile. Eighty percent of subjects had their first fracture by the age of 10 years, and one-third had a femoral or tibial fracture by the age of 25 years. Fractures continued into adulthood, though rates varied considerably. Healing was normal and rarely resulted in long bone deformity. One-third of subjects older than 15 years had scoliosis. The teeth and hearing were normal in most, and blue sclerae were not observed. Other features noted included fibro-osseous dysplasia of the mandible and Achilles tendon calcification. The mean spinal bone mineral density Z-score was +2.9 (SD 2.1) compared with -2.2 (0.7) in subjects with COL1A1 haploinsufficiency mutations. Bone mineral density distribution, assessed by quantitative backscattered electron imaging in bone showed higher levels of mineralization than found in any other disorder. Bone histology showed high trabecular volume and increased cortical thickness, with hyperosteoidosis and delayed mineralization. In vitro studies with cultured skin fibroblasts suggested that these mutations interfere with processing of the chain in which the sequence alteration occurs, but the C-propeptide is eventually cleaved (and detectable in blood), suggesting there are alternative sites of cleavage. The precise mechanism of the bony pathology is not yet clear. © 2018 American Society for Bone and Mineral Research.

Primary adrenal insufficiency (PAI) is a potentially life-threatening condition that can present with nonspecific features and can be difficult to diagnose. We undertook next generation sequencing in a cohort of children and young adults with PAI of unknown etiology from around the world and identified a heterozygous missense variant (rs6161, c.940G>A, p.Glu314Lys) in CYP11A1 in 19 individuals from 13 different families (allele frequency within undiagnosed PAI in our cohort, 0.102 vs 0.0026 in the Genome Aggregation Database; P < 0.0001). Seventeen individuals harbored a second heterozygous rare disruptive variant in CYP11A1 and two had very rare synonymous changes in trans (c.990G>A, Thr330 = ; c.1173C>T, Ser391 =). Although p.Glu314Lys is predicted to be benign and showed no loss-of-function in an Escherichia coli assay system, in silico and in vitro studies revealed that the rs6161/c.940G>A variant, plus the c.990G>A and c.1173C>T changes, affected splicing and that p.Glu314Lys produces a nonfunctional protein in mammalian cells. Taken together, these findings show that compound heterozygosity involving a relatively common and predicted “benign” variant in CYP11A1 is a major contributor to PAI of unknown etiology, especially in European populations. These observations have implications for personalized management and demonstrate how variants that might be overlooked in standard analyses can be pathogenic when combined with other very rare disruptive changes.

BACKGROUND: Maturity-onset diabetes of the young (MODY) is caused by autosomal dominant mutations in one of 13 confirmed genes. Estimates of MODY prevalence vary widely, as genetic screening is usually restricted based on clinical features, even in population studies. We aimed to determine prevalence of MODY variants in a large and unselected pediatric diabetes cohort. METHODS: MODY variants were assessed using massively parallel sequencing in the population-based diabetes cohort (n = 1363) of the sole tertiary pediatric diabetes service for Western Australia (population 2.6 million). All individuals were screened, irrespective of clinical features. MODY variants were also assessed in a control cohort (n = 993). RESULTS: DNA and signed consent were available for 821 children. Seventeen children had pathogenic/likely pathogenic variants in MODY genes, two diagnosed with type 2 diabetes, four diagnosed with antibody-negative type 1 diabetes (T1DM), three diagnosed with antibody-positive T1DM, and eight previously diagnosed with MODY. Prevalence of MODY variants in the sequenced cohort was 2.1%, compared to 0.3% of controls. CONCLUSIONS: This is the first comprehensive study of MODY variants in an unselected population-based pediatric diabetes cohort. The observed prevalence, increasing access to rapid and affordable genetic screening, and significant clinical implications suggest that genetic screening for MODY could be considered for all children with diabetes, irrespective of other clinical features.