Actionability and familial uptake following opportunistic genomic screening in a pediatric cancer cohort.

The care for patients with serious conditions is increasingly guided by genomic medicine, and genomic medicine may equally transform care for healthy individual if genomic population screening is implemented. This study examines the medical impact of opportunistic genomic screening (OGS) in a cohort of patients undergoing comprehensive genomic germline DNA testing for childhood cancer, including the impact on their relatives. Medical actionability and uptake after cascade testing in the period following disclosure of OGS results was quantified. A secondary finding was reported to 19/595 (3.2%) probands primarily in genes related to cardiovascular and lipid disorders. After a mean follow up time of 1.6 years (Interquartile range (IQR): 0.57-1.92 yrs.) only 12 (63%) of these variants were found to be medically actionable. Clinical follow up or treatment was planned in 16 relatives, and as in the probands, the prescribed treatment was primarily betablockers or cholesterol lowering therapy. No invasive procedures or implantation of medical devices were performed in probands or relatives, and no reproductive counseling was requested. After an average of 1.6 years of follow-up 2.25 relatives per family with an actionable finding had been tested. This real-world experience of OGS grants new insight into the practical implementation effects and derived health care demands of genotype-first screening. The resulting health care effect and impact on demand for genetic counseling and workup in relatives extends beyond the effect in the probands.

National Experiences from 30 Years of Provider-Mediated Cascade Testing in Lynch Syndrome Families-The Danish Model.

Cascade genetic testing and surveillance reduce morbidity and mortality in Lynch syndrome. However, barriers to conveying information about genetic disorders within families result in low uptake of genetic testing. Provider-mediated interventions may increase uptake but raise legal and ethical concerns. We describe 30 years of national experience with cascade genetic testing combining family- and provider-mediated contact in Lynch syndrome families in the Danish Hereditary Non-Polyposis Colorectal Cancer (HNPCC) Register. We aimed to estimate the added value of information letters to family members in Lynch syndrome families (provider-mediated contact) compared to family members not receiving such letters and thus relying on family-mediated contact. National clinical practice for cascade genetic testing, encompassing infrastructure, legislation, acceptance, and management of the information letters, is also discussed. Cascade genetic testing resulted in 7.3 additional tests per family. Uptake of genetic testing was 54.4% after family-mediated and 64.9% after provider-mediated contact, corresponding to an odds ratio of 1.8 (p < 0.001). The uptake of genetic testing was highest in the first year after diagnosis of Lynch syndrome in the family, with 72.5% tested after provider-mediated contact. In conclusion, the Danish model combining family- and provider-mediated contact can increase the effect of cascade genetic testing.

The evolutionary impact of childhood cancer on the human gene pool.

Germline pathogenic variants associated with increased childhood mortality must be subject to natural selection. Here, we analyze publicly available germline genetic metadata from 4,574 children with cancer [11 studies; 1,083 whole exome sequences (WES), 1,950 whole genome sequences (WGS), and 1,541 gene panel] and 141,456 adults [125,748 WES and 15,708 WGS]. We find that pediatric cancer predisposition syndrome (pCPS) genes [n = 85] are highly constrained, harboring only a quarter of the loss-of-function variants that would be expected. This strong indication of selective pressure on pCPS genes is found across multiple lines of germline genomics data from both pediatric and adult cohorts. For six genes [ELP1, GPR161, VHL and SDHA/B/C], a clear lack of mutational constraint calls the pediatric penetrance and/or severity of associated cancers into question. Conversely, out of 23 known pCPS genes associated with biallelic risk, two [9%, DIS3L2 and MSH2] show significant constraint, indicating that they may monoallelically increase childhood cancer risk. In summary, we show that population genetic data provide empirical evidence that heritable childhood cancer leads to natural selection powerful enough to have significantly impacted the present-day gene pool.

TINF2 is a major susceptibility gene in Danish patients with multiple primary melanoma.

TINF2 encodes the TINF2 protein, which is a subunit in the shelterin complex critical for telomere regulation. Three recent studies have associated six truncating germline variants in TINF2 that have previously been associated with a cancer predisposition syndrome (CPS) caused by elongation of the telomeres. This has added TINF2 to the long telomere syndrome genes, together with other telomere maintenance genes such as ACD, POT1, TERF2IP, and TERT. We report a clinical study of 102 Danish patients with multiple primary melanoma (MPM) in which a germline truncating variant in TINF2 (p.(Arg265Ter)) was identified in four unrelated participants. The telomere lengths of three variant carriers were >90% percentile. In a routine diagnostic setting, the variant was identified in two more families, including an additional MPM patient and monozygotic twins with thyroid cancer and other cancer types. A total of 10 individuals from six independent families were confirmed carriers, all with cancer history, predominantly melanoma. Our findings suggest a major role of TINF2 in Danish patients with MPM. In addition to melanoma, other cancers in the six families include thyroid, renal, breast, and sarcoma, supporting a CPS in which melanoma, thyroid cancer, and sarcoma predominate. Further studies are needed to establish the full spectrum of associated cancer types and characterize lifetime cancer risk in carriers.

Clinical practice guidelines for the diagnosis and surveillance of BAP1 tumour predisposition syndrome.

BRCA1-associated protein-1 (BAP1) is a recognised tumour suppressor gene. Germline BAP1 pathogenic/likely pathogenic variants are associated with predisposition to multiple tumours, including uveal melanoma, malignant pleural and peritoneal mesothelioma, renal cell carcinoma and specific non-malignant neoplasms of the skin, as part of the autosomal dominant BAP1-tumour predisposition syndrome. The overall lifetime risk for BAP1 carriers to develop at least one BAP1-associated tumour is up to 85%, although due to ascertainment bias, current estimates of risk are likely to be overestimated. As for many rare cancer predisposition syndromes, there is limited scientific evidence to support the utility of surveillance and, therefore, management recommendations for BAP1 carriers are based on expert opinion. To date, European recommendations for BAP1 carriers have not been published but are necessary due to the emerging phenotype of this recently described syndrome and increased identification of BAP1 carriers via large gene panels or tumour sequencing. To address this, the Clinical Guideline Working Group of the CanGene-CanVar project in the United Kingdom invited European collaborators to collaborate to develop guidelines to harmonize surveillance programmes within Europe. Recommendations with respect to BAP1 testing and surveillance were achieved following literature review and Delphi survey completed by a core group and an extended expert group of 34 European specialists including Geneticists, Ophthalmologists, Oncologists, Dermatologists and Pathologists. It is recognised that these largely evidence-based but pragmatic recommendations will evolve over time as further data from research collaborations informs the phenotypic spectrum and surveillance outcomes.

The effect of a single SMARCA4 exon deletion on RNA splicing: Implications for variant classification.

BACKGROUND: Exon deletions are generally considered pathogenic, particularly when they are located out of frame. Here, we describe a pediatric, female patient presenting with hypercalcemia and a small cell carcinoma of the ovary, hypercalcemic type, and carrying a germline de novo SMARCA4 exon 14 deletion. METHODS: The SMARCA4 deletion was identified by whole genome sequencing, and the effect on the RNA level was examined by gel- and capillary electrophoresis and nanopore sequencing. RESULTS: The deletion was in silico predicted to be truncating, but RNA analysis revealed two major transcripts with deletion of exon 14 alone or exon 14 through 15, where the latter was located in-frame. Because the patient's phenotype matched that of other patients with pathogenic germline variants in SMARCA4, the deletion was classified as likely pathogenic. CONCLUSION: We propose to include RNA analysis in classification of single-exon deletions, especially if located outside of known functional domains, as this can identify any disparate effects on the RNA and DNA level, which may have implications for variant classification using the American College of Medical Genetics and Genomics guidelines.

Germline (epi)genetics reveals high predisposition in females: a 5-year, nationwide, prospective Wilms tumour cohort.

BACKGROUND: Studies suggest that Wilms tumours (WT) are caused by underlying genetic (5%-10%) and epigenetic (2%-29%) mechanisms, yet studies covering both aspects are sparse. METHODS: We performed prospective whole-genome sequencing of germline DNA in Danish children diagnosed with WT from 2016 to 2021, and linked genotypes to deep phenotypes. RESULTS: Of 24 patients (58% female), 3 (13%, all female) harboured pathogenic germline variants in WT risk genes (FBXW7, WT1 and REST). Only one patient had a family history of WT (3 cases), segregating with the REST variant. Epigenetic testing revealed one (4%) additional patient (female) with uniparental disomy of chromosome 11 and Beckwith-Wiedemann syndrome (BWS). We observed a tendency of higher methylation of the BWS-related imprinting centre 1 in patients with WT than in healthy controls. Three patients (13%, all female) with bilateral tumours and/or features of BWS had higher birth weights (4780 g vs 3575 g; p=0.002). We observed more patients with macrosomia (>4250 g, n=5, all female) than expected (OR 9.98 (95% CI 2.56 to 34.66)). Genes involved in early kidney development were enriched in our constrained gene analysis, including both known (WT1, FBXW7) and candidate (CTNND1, FRMD4A) WT predisposition genes. WT predisposing variants, BWS and/or macrosomia (n=8, all female) were more common in female patients than male patients (p=0.01). CONCLUSION: We find that most females (57%) and 33% of all patients with WT had either a genetic or another indicator of WT predisposition. This emphasises the need for scrutiny when diagnosing patients with WT, as early detection of underlying predisposition may impact treatment, follow-up and genetic counselling.

Combinatorial batching of DNA for ultralow-cost detection of pathogenic variants.

BACKGROUND: Next-generation sequencing (NGS) based population screening holds great promise for disease prevention and earlier diagnosis, but the costs associated with screening millions of humans remain prohibitive. New methods for population genetic testing that lower the costs of NGS without compromising diagnostic power are needed. METHODS: We developed double batched sequencing where DNA samples are batch-sequenced twice - directly pinpointing individuals with rare variants. We sequenced batches of at-birth blood spot DNA using a commercial 113-gene panel in an explorative (n = 100) and a validation (n = 100) cohort of children who went on to develop pediatric cancers. All results were benchmarked against individual whole genome sequencing data. RESULTS: We demonstrated fully replicable detection of cancer-causing germline variants, with positive and negative predictive values of 100% (95% CI, 0.91-1.00 and 95% CI, 0.98-1.00, respectively). Pathogenic and clinically actionable variants were detected in RB1, TP53, BRCA2, APC, and 19 other genes. Analyses of larger batches indicated that our approach is highly scalable, yielding more than 95% cost reduction or less than 3 cents per gene screened for rare disease-causing mutations. We also show that double batched sequencing could cost-effectively prevent childhood cancer deaths through broad genomic testing. CONCLUSIONS: Our ultracheap genetic diagnostic method, which uses existing sequencing hardware and standard newborn blood spots, should readily open up opportunities for population-wide risk stratification using genetic screening across many fields of clinical genetics and genomics.

New pathogenic germline variants identified in mesothelioma.

BACKGROUND: Mesothelioma (MM) is associated with asbestos exposure, tumor heterogeneity and aggressive clinical behavior. Identification of germline pathogenic variants (PVs) in mesothelioma is relevant for identifying potential actionable targets and genetic counseling. METHODS: 44 patients underwent whole exome sequencing (WES) or whole genome sequencing (WGS). Germline variants were selected according to association with inherited cancer using a 168-gene in silico panel, and variants classified according to ACMG/AMP classification as pathogenic (class 5) or likely pathogenic (class 4). RESULTS: In total, 16 patients (36%) were found to carry pathogenic or likely pathogenic variants in 13 cancer associated genes (ATM, BAP1, BRCA2, CDKN2A, FANCA, FANCC, FANCD2, FANCM, MUTYH, NBN, RAD51B, SDHA and XPC). The germline PVs occurred in DNA repair pathways, including homologous recombination repair (HRR) (75%), nucleotide excision repair (6%), cell cycle regulatory (7%), base excision repair (6%), and hypoxic pathway (6%). Five (31%) patients with a germline PV had a first or second degree relative with mesothelioma compared to none for patients without a germline PV. Previously undiagnosed BRCA2 germline PVs were identified in two patients. Potential actionable targets based on the germline PVs were found in four patients (9%). CONCLUSION: This study revealed a high frequency of germline PVs in patients with mesothelioma. Furthermore, we identified germline PVs in two genes (NBN & RAD51B) not previously associated with mesothelioma. The data support germline testing in mesothelioma and provide a rationale for additional investigation of the HRR pathway as a potential actionable target.

RosettaDDGPrediction for high-throughput mutational scans: From stability to binding.

Reliable prediction of free energy changes upon amino acid substitutions (ΔΔGs) is crucial to investigate their impact on protein stability and protein-protein interaction. Advances in experimental mutational scans allow high-throughput studies thanks to multiplex techniques. On the other hand, genomics initiatives provide a large amount of data on disease-related variants that can benefit from analyses with structure-based methods. Therefore, the computational field should keep the same pace and provide new tools for fast and accurate high-throughput ΔΔG calculations. In this context, the Rosetta modeling suite implements effective approaches to predict folding/unfolding ΔΔGs in a protein monomer upon amino acid substitutions and calculate the changes in binding free energy in protein complexes. However, their application can be challenging to users without extensive experience with Rosetta. Furthermore, Rosetta protocols for ΔΔG prediction are designed considering one variant at a time, making the setup of high-throughput screenings cumbersome. For these reasons, we devised RosettaDDGPrediction, a customizable Python wrapper designed to run free energy calculations on a set of amino acid substitutions using Rosetta protocols with little intervention from the user. Moreover, RosettaDDGPrediction assists with checking completed runs and aggregates raw data for multiple variants, as well as generates publication-ready graphics. We showed the potential of the tool in four case studies, including variants of uncertain significance in childhood cancer, proteins with known experimental unfolding ΔΔGs values, interactions between target proteins and disordered motifs, and phosphomimetics. RosettaDDGPrediction is available, free of charge and under GNU General Public License v3.0, at https://github.com/ELELAB/RosettaDDGPrediction.

Genetic predisposition and evolutionary traces of pediatric cancer risk: a prospective 5-year population-based genome sequencing study of children with CNS tumors.

BACKGROUND: The etiology of central nervous system (CNS) tumors in children is largely unknown and population-based studies of genetic predisposition are lacking. METHODS: In this prospective, population-based study, we performed germline whole-genome sequencing in 128 children with CNS tumors, supplemented by a systematic pedigree analysis covering 3543 close relatives. RESULTS: Thirteen children (10%) harbored pathogenic variants in known cancer genes. These children were more likely to have medulloblastoma (OR 5.9, CI 1.6-21.2) and develop metasynchronous CNS tumors (P = 0.01). Similar carrier frequencies were seen among children with low-grade glioma (12.8%) and high-grade tumors (12.2%). Next, considering the high mortality of childhood CNS tumors throughout most of human evolution, we explored known pediatric-onset cancer genes, showing that they are more evolutionarily constrained than genes associated with risk of adult-onset malignancies (P = 5e-4) and all other genes (P = 5e-17). Based on this observation, we expanded our analysis to 2986 genes exhibiting high evolutionary constraint in 141,456 humans. This analysis identified eight directly causative loss-of-functions variants, and showed a dose-response association between degree of constraint and likelihood of pathogenicity-raising the question of the role of other highly constrained gene alterations detected. CONCLUSIONS: Approximately 10% of pediatric CNS tumors can be attributed to rare variants in known cancer genes. Genes associated with high risk of childhood cancer show evolutionary evidence of constraint.

Redefining germline predisposition in children with molecularly characterized ependymoma: a population-based 20-year cohort.

Ependymoma is the second most common malignant brain tumor in children. The etiology is largely unknown and germline DNA sequencing studies focusing on childhood ependymoma are limited. We therefore performed germline whole-genome sequencing on a population-based cohort of children diagnosed with ependymoma in Denmark over the past 20 years (n = 43). Single nucleotide and structural germline variants in 457 cancer related genes and 2986 highly evolutionarily constrained genes were assessed in 37 children with normal tissue available for sequencing. Molecular ependymoma classification was performed using DNA methylation profiling for 39 children with available tumor tissue. Pathogenic germline variants in known cancer predisposition genes were detected in 11% (4/37; NF2, LZTR1, NF1 & TP53). However, DNA methylation profiling resulted in revision of the histopathological ependymoma diagnosis to non-ependymoma tumor types in 8% (3/39). This included the two children with pathogenic germline variants in TP53 and NF1 whose tumors were reclassified to a diffuse midline glioma and a rosette-forming glioneuronal tumor, respectively. Consequently, 50% (2/4) of children with pathogenic germline variants in fact had other tumor types. A meta-analysis combining our findings with pediatric pan-cancer germline sequencing studies showed an overall frequency of pathogenic germline variants of 3.4% (7/207) in children with ependymoma. In summary, less than 4% of childhood ependymoma is explained by genetic predisposition, virtually restricted to pathogenic variants in NF2 and NF1. For children with other cancer predisposition syndromes, diagnostic reconsideration is recommended for ependymomas without molecular classification. Additionally, LZTR1 is suggested as a novel putative ependymoma predisposition gene.

Clinical implications of genetic testing in familial intermediate and late-onset colorectal cancer.

The genetic background of familial, late-onset colorectal cancer (CRC) (i.e., onset > age 50 years) has not been studied as thoroughly as other subgroups of familial CRC, and the proportion of families with a germline genetic predisposition to CRC remains to be defined. To define the contribution of known or suggested CRC predisposition genes to familial late-onset CRC, we analyzed 32 well-established or candidate CRC predisposition genes in 75 families with late-onset CRC. We identified pathogenic or likely pathogenic variants in five patients in MSH6 (n = 1), MUTYH (monoallelic; n = 2) and NTHL1 (monoallelic; n = 2). In addition, we identified a number of variants of unknown significance in particular in the lower penetrant Lynch syndrome-associated mismatch repair (MMR) gene MSH6 (n = 6). In conclusion, screening using a comprehensive cancer gene panel in families with accumulation of late-onset CRC appears not to have a significant clinical value due to the low level of high-risk pathogenic variants detected. Our data suggest that only patients with abnormal MMR immunohistochemistry (IHC) or microsatellite instability (MSI) analyses, suggestive of Lynch syndrome, or a family history indicating another cancer predisposition syndrome should be prioritized for such genetic evaluations. Variants in MSH6 and MUTYH have previously been proposed to be involved in digenic or oligogenic hereditary predisposition to CRC. Accumulation of variants in MSH6 and monoallelic, pathogenic variants in MUTYH in our study indicates that digenic or oligogenic inheritance might be involved in late-onset CRC and warrants further studies of complex types of inheritance.

von Hippel-Lindau disease: Updated guideline for diagnosis and surveillance.

von Hippel Lindau disease (vHL) is caused by a hereditary predisposition to multiple neoplasms, especially hemangioblastomas in the retina and CNS, renal cell carcinomas (RCC), pheochromocytomas, neuroendocrine pancreatic tumours (PNET) and endolymphatic sac tumours. Evidence based approaches are needed to ensure an optimal clinical care, while minimizing the burden for the patients and their families. This guideline is based on evidence from the international vHL literature and extensive research of geno- and phenotypic characteristics, disease progression and surveillance effect in the national Danish vHL cohort. We included the views and preferences of the Danish vHL patients, ensured consensus among Danish experts and compared with international recommendations. RECOMMENDATIONS: vHL can be diagnosed on clinical criteria, only; however, in most cases the diagnosis can be supported by identification of a pathogenic or likely pathogenic variant in VHL. Surveillance should be initiated in childhood in persons with, or at risk of, vHL, and include regular examination of the retina, CNS, inner ear, kidneys, neuroendocrine glands, and pancreas. Treatment of vHL manifestations should be planned to optimize the chance of cure, without unnecessary sequelae. Most manifestations are currently treated by surgery. However, belzutifan, that targets HIF-2α was recently approved by the U.S. Food and Drug Administration (FDA) for adult patients with vHL-associated RCC, CNS hemangioblastomas, or PNETs, not requiring immediate surgery. Diagnostics, surveillance, and treatment of vHL can be undertaken successfully by experts collaborating in multidisciplinary teams. Systematic registration, collaboration with patient organisations, and research are fundamental for the continuous improvement of clinical care and optimization of outcome with minimal patient inconvenience.

Cancer-related Mutations with Local or Long-range Effects on an Allosteric Loop of p53.

The tumor protein 53 (p53) is involved in transcription-dependent and independent processes. Several p53 variants related to cancer have been found to impact protein stability. Other variants, on the contrary, might have little impact on structural stability and have local or long-range effects on the p53 interactome. Our group previously identified a loop in the DNA binding domain (DBD) of p53 (residues 207-213) which can recruit different interactors. Experimental structures of p53 in complex with other proteins strengthen the importance of this interface for protein-protein interactions. We here characterized with structure-based approaches somatic and germline variants of p53 which could have a marginal effect in terms of stability and act locally or allosterically on the region 207-213 with consequences on the cytosolic functions of this protein. To this goal, we studied 1132 variants in the p53 DBD with structure-based approaches, accounting also for protein dynamics. We focused on variants predicted with marginal effects on structural stability. We then investigated each of these variants for their impact on DNA binding, dimerization of the p53 DBD, and intramolecular contacts with the 207-213 region. Furthermore, we identified variants that could modulate long-range the conformation of the region 207-213 using a coarse-grain model for allostery and all-atom molecular dynamics simulations. Our predictions have been further validated using enhanced sampling methods for 15 variants. The methodologies used in this study could be more broadly applied to other p53 variants or cases where conformational changes of loop regions are essential in the function of disease-related proteins.

Recurrent Germline Variant in RAD21 Predisposes Children to Lymphoblastic Leukemia or Lymphoma.

Somatic loss of function mutations in cohesin genes are frequently associated with various cancer types, while cohesin disruption in the germline causes cohesinopathies such as Cornelia-de-Lange syndrome (CdLS). Here, we present the discovery of a recurrent heterozygous RAD21 germline aberration at amino acid position 298 (p.P298S/A) identified in three children with lymphoblastic leukemia or lymphoma in a total dataset of 482 pediatric cancer patients. While RAD21 p.P298S/A did not disrupt the formation of the cohesin complex, it altered RAD21 gene expression, DNA damage response and primary patient fibroblasts showed increased G2/M arrest after irradiation and Mitomycin-C treatment. Subsequent single-cell RNA-sequencing analysis of healthy human bone marrow confirmed the upregulation of distinct cohesin gene patterns during hematopoiesis, highlighting the importance of RAD21 expression within proliferating B- and T-cells. Our clinical and functional data therefore suggest that RAD21 germline variants can predispose to childhood lymphoblastic leukemia or lymphoma without displaying a CdLS phenotype.

9p21.3 Microdeletion involving CDKN2A/2B in a young patient with multiple primary cancers and review of the literature.

Germline pathogenic variants in CDKN2A predispose to various cancers, including melanoma, pancreatic cancer, and neural system tumors, whereas CDKN2B variants are associated with renal cell carcinoma. A few case reports have described heterozygous germline deletions spanning both CDKN2A and CDKN2B associated with a cancer predisposition syndrome (CPS) that constitutes a risk of cancer beyond those associated with haploinsufficiency of each gene individually, indicating an additive effect or a contiguous gene deletion syndrome. We report a young woman with a de novo germline 9p21 microdeletion involving the CDKN2A/CDKN2B genes, who developed six primary cancers since childhood, including a very rare extraskeletal osteosarcoma (eOS) at the age of 8. To our knowledge this is the first report of eOS in a patient with CDKN2A/CDKN2B deletion.

Risk of somatic hospitalization in parents after cancer in a child, a nationwide cohort study.

OBJECTIVE: The diagnosis of cancer in a child is a profoundly stressful experience. The impact on parents' somatic health, including lifestyle-related diseases, however, is unresolved. This paper assesses parents' risk of hospitalization with somatic disease after a child's cancer diagnosis. METHODS: We conducted a nationwide population- and register-based study with parents of all children under age 20 diagnosed with cancer in Denmark between 1998 and 2013 and parents of cancer-free children, matched (1:10) on child's age and family type. We estimated HR with 95% CI in Cox proportional hazard models for 13 major International Classification of Diseases-10 disease groups, selected stress- and lifestyle-related disease-groups, and investigated moderation by time since diagnosis, parental sex, and cancer type. RESULTS: Among n = 7797 parents of children with cancer compared with n = 74,388 parents of cancer-free children (51% mothers, mean age 42), we found no overall pattern of increased risk for 13 broad disease groups. We found increases in digestive system diseases (HR 1.06, 95% CI 1.01-1.12), genitourinary system diseases (HR 1.08, 95% CI 1.02-1.14), and neoplasms (HR 1.20, 95% CI 1.13-1.27), the latter attributable mostly to increased rates of tobacco-related cancers and mothers' diet-related cancers. CONCLUSIONS: This is the first attempt to document the impact of childhood cancer on parents' somatic health. With the exception of increased risk for neoplasms, likely due to shared genetic or lifestyle factors, our findings offer the reassuring message, that the burden of caring for a child with cancer does not in general increase parents' risk for somatic diseases.