Prdm16 mutation determines sex-specific cardiac metabolism and identifies two novel cardiac metabolic regulators

AIMS

Mutation of the PRDM16 gene causes human dilated and non-compaction cardiomyopathy. The PRDM16 protein is a transcriptional regulator that affects cardiac development via Tbx5 and Hand1, thus regulating myocardial structure. The biallelic inactivation of Prdm16 induces severe cardiac dysfunction with post-natal lethality and hypertrophy in mice. The early pathological events that occur upon Prdm16 inactivation have not been explored.

METHODS AND RESULTS

This study performed in-depth pathophysiological and molecular analyses of male and female Prdm16csp1/wt mice that carry systemic, monoallelic Prdm16 gene inactivation. We systematically assessed early molecular changes through transcriptomics, proteomics, and metabolomics. Kinetic modelling of cardiac metabolism was performed in silico with CARDIOKIN. Prdm16csp1/wt mice are viable up to 8 months, develop hypoplastic hearts, and diminished systolic performance that is more pronounced in female mice. Prdm16csp1/wt cardiac tissue of both sexes showed reductions in metabolites associated with amino acid as well as glycerol metabolism, glycolysis, and the tricarboxylic acid cycle. Prdm16csp1/wt cardiac tissue revealed diminished glutathione (GSH) and increased inosine monophosphate (IMP) levels indicating oxidative stress and a dysregulated energetics, respectively. An accumulation of triacylglycerides exclusively in male Prdm16csp1/wt hearts suggests a sex-specific metabolic adaptation. Metabolic modelling using CARDIOKIN identified a reduction in fatty acid utilization in males as well as lower glucose utilization in female Prdm16csp1/wt cardiac tissue. On the level of transcripts and protein expression, Prdm16csp1/wt hearts demonstrate an up-regulation of pyridine nucleotide-disulphide oxidoreductase domain 2 (Pyroxd2) and the transcriptional regulator pre-B-cell leukaemia transcription factor interacting protein 1 (Pbxip1). The strongest concordant transcriptional up-regulation was detected for Prdm16 itself, probably through an autoregulatory mechanism.

CONCLUSIONS

Monoallelic, global Prdm16 mutation diminishes cardiac performance in Prdm16csp1/wt mice. Metabolic alterations and transcriptional dysregulation in Prdm16csp1/wt affect cardiac tissue. Female Prdm16csp1/wt mice develop a more pronounced phenotype, indicating sexual dimorphism at this early pathological window. This study suggests that metabolic dysregulation is an early event in the PRDM16 associated cardiac pathology.

Correction: Integrative analysis of genomic variants reveals new associations of candidate haploinsufficient genes with congenital heart disease

[This corrects the article DOI: 10.1371/journal.pgen.1009679.].

Integrative analysis of genomic variants reveals new associations of candidate haploinsufficient genes with congenital heart disease

Numerous genetic studies have established a role for rare genomic variants in Congenital Heart Disease (CHD) at the copy number variation (CNV) and de novo variant (DNV) level. To identify novel haploinsufficient CHD disease genes, we performed an integrative analysis of CNVs and DNVs identified in probands with CHD including cases with sporadic thoracic aortic aneurysm. We assembled CNV data from 7,958 cases and 14,082 controls and performed a gene-wise analysis of the burden of rare genomic deletions in cases versus controls. In addition, we performed variation rate testing for DNVs identified in 2,489 parent-offspring trios. Our analysis revealed 21 genes which were significantly affected by rare CNVs and/or DNVs in probands. Fourteen of these genes have previously been associated with CHD while the remaining genes (FEZ1, MYO16, ARID1B, NALCN, WAC, KDM5B and WHSC1) have only been associated in small cases series or show new associations with CHD. In addition, a systems level analysis revealed affected protein-protein interaction networks involved in Notch signaling pathway, heart morphogenesis, DNA repair and cilia/centrosome function. Taken together, this approach highlights the importance of re-analyzing existing datasets to strengthen disease association and identify novel disease genes and pathways.

Correction: Diagnostic value of partial exome sequencing in developmental disorders

[This corrects the article DOI: 10.1371/journal.pone.0201041.].

Expanding the genotypic and phenotypic spectrum of severe serine biosynthesis disorders

Serine biosynthesis disorders comprise a spectrum of very rare autosomal recessive inborn errors of metabolism with wide phenotypic variability. Neu-Laxova syndrome represents the most severe expression and is characterized by multiple congenital anomalies and pre- or perinatal lethality. Here, we present the mutation spectrum and a detailed phenotypic analysis in 15 unrelated families with severe types of serine biosynthesis disorders. We identified likely disease-causing variants in the PHGDH and PSAT1 genes, several of which have not been reported previously. Phenotype analysis and a comprehensive review of the literature corroborates the evidence that serine biosynthesis disorders represent a continuum with varying degrees of phenotypic expression and suggest that even gradual differences at the severe end of the spectrum may be correlated with particular genotypes. We postulate that the individual residual enzyme activity of mutant proteins is the major determinant of the phenotypic variability, but further functional studies are needed to explore effects at the enzyme protein level.

Knocking out C9ORF72 Exacerbates Axonal Trafficking Defects Associated with Hexanucleotide Repeat Expansion and Reduces Levels of Heat Shock Proteins

In amyotrophic lateral sclerosis (ALS) motor neurons (MNs) undergo dying-back, where the distal axon degenerates before the soma. The hexanucleotide repeat expansion (HRE) in C9ORF72 is the most common genetic cause of ALS, but the mechanism of pathogenesis is largely unknown with both gain- and loss-of-function mechanisms being proposed. To better understand C9ORF72-ALS pathogenesis, we generated isogenic induced pluripotent stem cells. MNs with HRE in C9ORF72 showed decreased axonal trafficking compared with gene corrected MNs. However, knocking out C9ORF72 did not recapitulate these changes in MNs from healthy controls, suggesting a gain-of-function mechanism. In contrast, knocking out C9ORF72 in MNs with HRE exacerbated axonal trafficking defects and increased apoptosis as well as decreased levels of HSP70 and HSP40, and inhibition of HSPs exacerbated ALS phenotypes in MNs with HRE. Therefore, we propose that the HRE in C9ORF72 induces ALS pathogenesis via a combination of gain- and loss-of-function mechanisms.

De Novo Variants in TAOK1 Cause Neurodevelopmental Disorders

De novo variants represent a significant cause of neurodevelopmental delay and intellectual disability. A genetic basis can be identified in only half of individuals who have neurodevelopmental disorders (NDDs); this indicates that additional causes need to be elucidated. We compared the frequency of de novo variants in patient-parent trios with (n = 2,030) versus without (n = 2,755) NDDs. We identified de novo variants in TAOK1 (thousand and one [TAO] amino acid kinase 1), which encodes the serine/threonine-protein kinase TAO1, in three individuals with NDDs but not in persons who did not have NDDs. Through further screening and the use of GeneMatcher, five additional individuals with NDDs were found to have de novo variants. All eight variants were absent from gnomAD (Genome Aggregation Database). The variant carriers shared a non-specific phenotype of developmental delay, and six individuals had additional muscular hypotonia. We established a fibroblast line of one mutation carrier, and we demonstrated that reduced mRNA levels of TAOK1 could be increased upon cycloheximide treatment. These results indicate nonsense-mediated mRNA decay. Further, there was neither detectable phosphorylated TAO1 kinase nor phosphorylated tau in these cells, and mitochondrial morphology was altered. Knockdown of the ortholog gene Tao1 (Tao, CG14217) in Drosophila resulted in delayed early development. The majority of the Tao1-knockdown flies did not survive beyond the third instar larval stage. When compared to control flies, Tao1 knockdown flies revealed changed morphology of the ventral nerve cord and the neuromuscular junctions as well as a decreased number of endings (boutons). Furthermore, mitochondria in mutant flies showed altered distribution and decreased size in axons of motor neurons. Thus, we provide compelling evidence that de novo variants in TAOK1 cause NDDs.

DNA methylation profiling allows for characterization of atrial and ventricular cardiac tissues and hiPSC-CMs

Background

Cardiac disease modelling using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) requires thorough insight into cardiac cell type differentiation processes. However, current methods to discriminate different cardiac cell types are mostly time-consuming, are costly and often provide imprecise phenotypic evaluation. DNA methylation plays a critical role during early heart development and cardiac cellular specification. We therefore investigated the DNA methylation pattern in different cardiac tissues to identify CpG loci for further cardiac cell type characterization.

Results

An array-based genome-wide DNA methylation analysis using Illumina Infinium HumanMethylation450 BeadChips led to the identification of 168 differentially methylated CpG loci in atrial and ventricular human heart tissue samples (n = 49) from different patients with congenital heart defects (CHD). Systematic evaluation of atrial-ventricular DNA methylation pattern in cardiac tissues in an independent sample cohort of non-failing donor hearts and cardiac patients using bisulfite pyrosequencing helped us to define a subset of 16 differentially methylated CpG loci enabling precise characterization of human atrial and ventricular cardiac tissue samples. This defined set of reproducible cardiac tissue-specific DNA methylation sites allowed us to consistently detect the cellular identity of hiPSC-CM subtypes.

Conclusion

Testing DNA methylation of only a small set of defined CpG sites thus makes it possible to distinguish atrial and ventricular cardiac tissues and cardiac atrial and ventricular subtypes of hiPSC-CMs. This method represents a rapid and reliable system for phenotypic characterization of in vitro-generated cardiomyocytes and opens new opportunities for cardiovascular research and patient-specific therapy.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0679-0) contains supplementary material, which is available to authorized users.

Patients with congenital heart defect and their families support genetic heart research

BACKGROUND

Congenital heart disease (CHD) affects up to 1% of live births the etiology remains relatively poorly understood. Thus, cardiac research is needed to understand the underlying pathomechanisms of the disease. About 51 000 CHD patients are registered in the German National Register for Congenital Heart Defects (NRCHD). Patients and relatives were interviewed online about their willingness to support genetic heart research in order to donate a biological sample.

METHODS

Study participants were recruited via the database of the NRCHD. Seven thousand nine hundred eighty-nine patients were invited to participate in the study. Participants have been asked to rate three questions on a ten-staged Likert scale about their willingness to provide a saliva/blood sample and their motivation to ask family members to support genetic heart research.

RESULTS

Overall, 2035 participants (patients/relatives) responded the online survey (25.5%). Two-thirds of the participants are willing to donate a saliva sample. Whereas the motivation to provide a blood sample is slightly lower (patients: 63.8%, relatives: 60.6%). Female relatives are more fain to provide a saliva sample as well as a blood sample compared to men (saliva sample: P < .001, blood sample: P < .01). The motivation to ask an additional family member for a biological sample was significantly higher in relatives (59.2%) compared to patients (48.4%).

CONCLUSIONS

The motivation to provide biological samples is high reflecting the need for genetic research to unravel the pathomechanism of CHD. A future aim should be to offer an individual risk assessment for each patient based on the underlying genetics.

Diagnostic value of partial exome sequencing in developmental disorders

Although intellectual disability is one of the major indications for genetic counselling, there are no homogenous diagnostic algorithms for molecular testing. While whole exome sequencing is increasingly applied, we questioned whether analyzing a partial exome, enriched for genes associated with Mendelian disorders, might be a valid alternative approach that yields similar detection rates but requires less sequencing capacities. Within this context 106 patients with different intellectual disability forms were analyzed for mutations in 4.813 genes after pre-exclusion of copy number variations by array-CGH. Subsequent variant interpretation was performed in accordance with the ACMG guidelines. By this, a molecular diagnosis was established in 34% of cases and candidate mutations were identified in additional 24% of patients. Detection rates of causative mutations were above 30%, regardless of further symptoms, except for patients with seizures (23%). We did not detect an advantage from partial exome sequencing for patients with severe intellectual disability (36%) as compared to those with mild intellectual disability (44%). Specific clinical diagnoses pre-existed for 20 patients. Of these, 5 could be confirmed and an additional 6 cases could be solved, but showed mutations in other genes than initially suspected. In conclusion partial exome sequencing solved >30% of intellectual disability cases, which is similar to published rates obtained by whole exome sequencing. The approach therefore proved to be a valid alternative to whole exome sequencing for molecular diagnostics in this cohort. The method proved equally suitable for both syndromic and non-syndromic intellectual disability forms of all severity grades.

Abstract 1410: Pedigree analysis equally identifies cases of pancreatic cancer in families with BRCA1 and BRCA2 mutations

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in western countries, although lifetime risk is estimated at only 1.3% in the general population. BRCA2 mutations, however, have been attributed with a lifetime risk for PDAC development of 5-10%, while the risk for PDAC development in BRCA1 mutation carriers has been the subject of an ongoing scientific discussion, with current estimates of an increased PDAC risk of only 2-4-fold.

We retrospectively analyzed 180 pedigrees for occurrence of PDAC. All families were counselled for hereditary breast and ovarian cancer (HBOC) within three years (2015 to 2017) at the Center for Hereditary Breast and Ovarian Cancer in Dresden. The pedigrees of 111 families with a pathogenic

BRCA1 germline mutation and of 69 families with a pathogenic BRCA2 germline mutation were available for analysis. Whenever possible genetic testing (NGS or targeted sequencing) was performed using blood and/or tumor tissue of affected individuals. 14 “BRCA1 families” were identified to have at least one family member affected by PDAC (12.6% of families). Three of the patients were available for testing and carrier status could be confirmed in all of them. According to formal genetic risk calculation 6 of the PDAC patients had a mutation carrier risk of 50%, 5 of 25% and 1 of 12.5%. Age of onset (AO) of the disease was known in 13 of the families and the mean AO, calculated for these patients, was 58.7 years. Interestingly, two female Mutation carriers had both breast- and pancreatic cancer and one family with a BRCA1 mutation presented

with two sisters with PDAC. Tumor tissue was available from one of them and sequencing indicated loss-of-heterozygosity, supporting the assumption that the BRCA1 mutation might have been causative for tumorigenesis.

Of the “BRCA2 families” 10 (14,5%) were identified to have one family member each with PDAC. To date, however, none of them was available for genetic testing. 3 of the patients had a mutation carrier risk calculated at 50%, 5 at 25%, 1 at 12.5% and 1 at 6.25%. The mean AO was calculated to be 60.1 years. One female PDAC patient additionally had breast cancer and one of the male patients also suffered from prostate cancer. While the number of families represented in this retrospective study is limited, our observations indicate that BRCA1 mutations might be underdiagnosed in PDAC, especially in patients with an earlier AO. Extensive genetic analyses of PDAC patients will be necessary in order to elucidate this presumption and could also indicate whether additional genetic risk modifiers play a role in PAC development in BRCA1/2 families.

Citation Format: Evelin Schrock, Karl Hackmann, Franziska Kuhlee, Arne Jahn, Johannes Wagner, Anne-Karin Kahlert, Joseph Porrmann, Andreas Tzschach, Daniela Aust, Gustavo Baretton, Karin Kast, Pauline Wimberger, Michael Laniado, Christoph Kahlert, Thilo Welsch, Jürgen Weitz, Barbara Klink, Andreas Rump, Laura Gieldon. Pedigree analysis equally identifies cases of pancreatic cancer in families with BRCA1 and BRCA2 mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1410.

Novel truncating PPM1D mutation in a patient with intellectual disability

Truncating mutations in the last and penultimate exons of the PPM1D gene were recently described as a cause for mild to severe intellectual disability in fourteen patients. Feeding difficulties, periods of fever and vomiting as well as a high pain threshold were described as additional characteristic features and the disorder was subsequently termed "intellectual developmental disorder with gastrointestinal difficulties and high pain threshold (IDDGIP)" in the OMIM database (MIM # 617450). Here we report on an additional patient carrying a novel de novo truncating mutation NM_003620.3: c.1535del, p.(Asn512Ilefs*2) in the last exon of PPM1D. While the patient showed features overlapping with the reported phenotype, such as a short stature and small hands and feet, he also presented with additional features like cleft lip and palate and an aberrant right subclavian artery. Notably, the patient did not have any gastrointestinal difficulties or periods of fever, indicating variability of the phenotype of patients with PPM1D mutations.

BRIP1 loss-of-function mutations confer high risk for familial ovarian cancer, but not familial breast cancer

Background

Germline mutations in the BRIP1 gene have been described as conferring a moderate risk for ovarian cancer (OC), while the role of BRIP1 in breast cancer (BC) pathogenesis remains controversial.

Methods

To assess the role of deleterious BRIP1 germline mutations in BC/OC predisposition, 6341 well-characterized index patients with BC, 706 index patients with OC, and 2189 geographically matched female controls were screened for loss-of-function (LoF) mutations and potentially damaging missense variants. All index patients met the inclusion criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for germline testing and tested negative for pathogenic BRCA1/2 variants.

Results

BRIP1 LoF mutations confer a high OC risk in familial index patients (odds ratio (OR) = 20.97, 95% confidence interval (CI) = 12.02–36.57, P < 0.0001) and in the subgroup of index patients with late-onset OC (OR = 29.91, 95% CI = 14.99–59.66, P < 0.0001). No significant association of BRIP1 LoF mutations with familial BC was observed (OR = 1.81 95% CI = 1.00–3.30, P = 0.0623). In the subgroup of familial BC index patients without a family history of OC there was also no apparent association (OR = 1.42, 95% CI = 0.70–2.90, P = 0.3030). In 1027 familial BC index patients with a family history of OC, the BRIP1 mutation prevalence was significantly higher than that observed in controls (OR = 3.59, 95% CI = 1.43–9.01; P = 0.0168). Based on the negative association between BRIP1 LoF mutations and familial BC in the absence of an OC family history, we conclude that the elevated mutation prevalence in the latter cohort was driven by the occurrence of OC in these families. Compared with controls, predicted damaging rare missense variants were significantly more prevalent in OC (P = 0.0014) but not in BC (P = 0.0693) patients.

Conclusions

To avoid ambiguous results, studies aimed at assessing the impact of candidate predisposition gene mutations on BC risk might differentiate between BC index patients with an OC family history and those without. In familial cases, we suggest that BRIP1 is a high-risk gene for late-onset OC but not a BC predisposition gene, though minor effects cannot be excluded.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0935-9) contains supplementary material, which is available to authorized users.

Association Between Loss-of-Function Mutations Within the FANCM Gene and Early-Onset Familial Breast Cancer

Importance

Germline mutations in established moderately or highly penetrant risk genes for breast cancer (BC) and/or ovarian cancer (OC), including BRCA1 and BRCA2, explain fewer than half of all familial BC and/or OC cases. Based on the genotyping of 2 loss-of-function (LoF) variants c.5101C>T (p.GIn1701Ter [rs147021911]) and c.5791C>T (p.Arg1931Ter [rs144567652]), the FANCM gene has been suggested as a novel BC predisposition gene, while the analysis of the entire coding region of the FANCM gene in familial index cases and geographically matched controls is pending.

Objectives

To assess the mutational spectrum within the FANCM gene, and to determine a potential association of LoF germline mutations within the FANCM gene with BC and/or OC risk.

Design, Setting, and Participants

For the purpose of identification and characterization of novel BC and/or OC predisposition genes, a total of 2047 well-characterized familial BC index cases, 628 OC cases, and 2187 geographically matched controls were screened for LoF mutations within the FANCM gene by next-generation sequencing. All patients previously tested negative for pathogenic BRCA1 and BRCA2 mutations. All data collection occurred between June 1, 2013, and April 30, 2016. Data analysis was performed from May 1, 2016, to July 1, 2016.

Main Outcomes and Measures

FANCM LoF mutation frequencies in patients with BC and/or OC were compared with the FANCM LoF mutation frequencies in geographically matched controls by univariate logistic regression. Positive associations were stratified by age at onset and cancer family history.

Results

In this case-control study, 2047 well-characterized familial female BC index cases, 628 OC cases, and 2187 geographically matched controls were screened for truncating FANCM alterations. Heterozygous LoF mutations within the FANCM gene were significantly associated with familial BC risk, with an overall odds ratio (OR) of 2.05 (95% CI, 0.94-4.54; P = .049) and a mutation frequency of 1.03% in index cases. In familial patients whose BC onset was before age 51 years, an elevated OR of 2.44 (95% CI, 1.08-5.59; P = .02) was observed. A more pronounced association was identified for patients with a triple-negative BC tumor phenotype (OR, 3.75; 95% CI, 1.00-12.85; P = .02). No significant association was detected for unselected OC cases (OR, 1.74; 95% CI, 0.57-5.08; P = .27).

Conclusions and Relevance

Based on the significant associations of heterozygous LoF mutations with early-onset or triple-negative BC, FANCM should be included in diagnostic gene panel testing for individual risk assessment. Larger studies are required to determine age-dependent disease risks for BC and to assess a potential role of FANCM mutations in OC pathogenesis.

Novel PRPS1 gain-of-function mutation in a patient with congenital hyperuricemia and facial anomalies

Phosphoribosylpyrophosphate synthetase (PRPPS) superactivity (OMIM 300661) is a rare inborn error of purine metabolism that is caused by gain-of-function mutations in the X-chromosomal gene PRPS1 (Xq22.3). Clinical characteristics include congenital hyperuricemia and hyperuricosuria, gouty arthritis, urolithiasis, developmental delay, hypotonia, recurrent infections, short stature, and hearing loss. Only eight families with PRPPS superactivity and PRPS1 gain-of-function mutations have been reported to date. We report on a 7-year-old boy with congenital hyperuricemia, urolithiasis, developmental delay, short stature, hypospadias, and facial dysmorphisms. His mother also suffered from hyperuricemia that was diagnosed at age 13 years. A novel PRPS1 missense mutation (c.573G>C, p.[Leu191Phe]) was detected in the proband and his mother. Enzyme activity analysis confirmed superactivity of PRPP synthetase. Analysis of the crystal structure of human PRPPS suggests that the Leu191Phe mutation affects the architecture of both allosteric sites, thereby preventing the allosteric inhibition of the enzyme. The family reported here broadens the clinical spectrum of PRPPS superactivity and indicates that this rare metabolic disorder might be associated with a recognizable facial gestalt.

Distinct genetic architectures for syndromic and nonsyndromic congenital heart defects identified by exome sequencing

Congenital heart defects (CHDs) have a neonatal incidence of 0.8-1% (refs. 1,2). Despite abundant examples of monogenic CHD in humans and mice, CHD has a low absolute sibling recurrence risk (∼2.7%), suggesting a considerable role for de novo mutations (DNMs) and/or incomplete penetrance. De novo protein-truncating variants (PTVs) have been shown to be enriched among the 10% of 'syndromic' patients with extra-cardiac manifestations. We exome sequenced 1,891 probands, including both syndromic CHD (S-CHD, n = 610) and nonsyndromic CHD (NS-CHD, n = 1,281). In S-CHD, we confirmed a significant enrichment of de novo PTVs but not inherited PTVs in known CHD-associated genes, consistent with recent findings. Conversely, in NS-CHD we observed significant enrichment of PTVs inherited from unaffected parents in CHD-associated genes. We identified three genome-wide significant S-CHD disorders caused by DNMs in CHD4, CDK13 and PRKD1. Our study finds evidence for distinct genetic architectures underlying the low sibling recurrence risk in S-CHD and NS-CHD.

Ready to clone: CNV detection and breakpoint fine-mapping in breast and ovarian cancer susceptibility genes by high-resolution array CGH

PURPOSE

Detection of predisposing copy number variants (CNV) in 330 families affected with hereditary breast and ovarian cancer (HBOC).

METHODS

In order to complement mutation detection with Illumina's TruSight Cancer panel, we designed a customized high-resolution 8 × 60k array for CGH (aCGH) that covers all 94 genes from the panel.

RESULTS

Copy number variants with immediate clinical relevance were detected in 12 families (3.6%). Besides 3 known CNVs in CHEK2, RAD51C, and BRCA1, we identified 3 novel pathogenic CNVs in BRCA1 (deletion of exons 4-13, deletion of exons 12-18) and ATM (deletion exons 57-63) plus an intragenic duplication of BRCA2 (exons 3-11) and an intronic BRCA1 variant with unknown pathogenicity. The precision of high-resolution aCGH enabled straight forward breakpoint amplification of a BRCA1 deletion which subsequently allowed for fast and economic CNV verification in family members of the index patient. Furthermore, we used our aCGH data to validate an algorithm that was able to detect all identified copy number changes from next-generation sequencing (NGS) data.

CONCLUSIONS

Copy number detection is a mandatory analysis in HBOC families at least if no predisposing mutations were found by sequencing. Currently, high-resolution array CGH is our first choice of method of analysis due to unmatched detection precision. Although it seems possible to detect CNV from sequencing data, there currently is no satisfying tool to do so in a routine diagnostic setting.