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Telomere biology disorder (TBD) can present within a wide spectrum of symptoms ranging from severe congenital malformations to isolated organ dysfunction in adulthood. Diagnosing TBD can be challenging given the substantial variation in symptoms and age of onset across generations. In this report, we present two families, one with a pathogenic variant in ZCCHC8 and another with a novel variant in TERC. In the literature, only one family has previously been reported with a ZCCHC8 variant and TBD symptoms. This family had multiple occurrences of pulmonary fibrosis and one case of bone marrow failure. In this paper, we present a second family with the same ZCCHC8 variant (p.Pro186Leu) and symptoms of TBD including pulmonary fibrosis, hematological disease, and elevated liver enzymes. The suspicion of TBD was confirmed with the measurement of short telomeres in the proband. In another family, we report a novel likely pathogenic variant in TERC. Our comprehensive description encompasses hematological manifestations, as well as pulmonary and hepatic fibrosis. Notably, there are no other reports which associate this variant to disease. The families expand our understanding of the clinical implications and genetic causes of TBD. [ABSTRACT FROM AUTHOR]

Juvenile polyposis syndrome (JPS) is a hereditary hamartomatous polyposis syndrome characterized by gastrointestinal juvenile polyps and increased risk of gastrointestinal cancer. Germline pathogenic variants are detected in SMAD4 or BMPR1A, however in a significant number of patients with JPS, the etiology is unknown. From Danish registers, and genetic department and laboratories, we identified all patients in Denmark with a clinical diagnosis of JPS and/or a pathogenic variant in BMPR1A or SMAD4. In patients where no variant had been detected, we performed genetic analysis, including whole genome sequencing. We collected clinical information on all patients to investigate the phenotypic spectrum. Sixty-six patients (mean age 40 years) were included of whom the pathogenic variant was unknown in seven patients. We detected a pathogenic variant in SMAD4 or PTEN in additional three patients and thus ≈ 95% of patients had a pathogenic germline variant. Endoscopic information was available in fifty-two patients (79%) and of these 31 (60%) fulfilled the clinical criteria of JPS. In 41 patients (79%), other types of polyps than juvenile had been removed. Our results suggest that almost all patients with a clinical diagnosis of JPS has a pathogenic variant in mainly BMPR1A, SMAD4, and more rarely PTEN. However, not all patients with a pathogenic variant fulfil the clinical criteria of JPS. We also demonstrated a wide clinical spectrum, and that the histopathology of removed polyps varied. [ABSTRACT FROM AUTHOR]

Peutz–Jeghers syndrome (PJS) is an autosomal dominant hereditary polyposis syndrome causing increased morbidity and mortality due to complications of polyposis and the development of cancer. STK11 is the only gene known to be associated with PJS, although in 10%–15% of patients fulfilling the diagnostic criteria no pathogenic variant (PV) is identified. The primary aim of this study was to identify the genetic etiology in all known PJS patients in Denmark and to estimate the risk of cancer, effect of surveillance and overall survival. We identified 56 patients (2–83 years old) with PJS. The detection rate of PVs was 96%, including three cases of mosaicism (6%). In two patients a variant was not detected. At the age of 40 years, the probabilities of cancer and death were 21% and 16%, respectively; at the age of 70 years these probabilities were 71% and 69%. Most cases of cancer (92%) were identified between the scheduled examinations in the surveillance program. These observations emphasize that PJS should be regarded as a general cancer predisposition syndrome, where improvement of clinical care is needed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

We present a three-generation family with an AXIN2 variant and a family history of colorectal cancer (CRC), colon polyps and tooth agenesis. A likely pathogenic variant was detected in the AXIN2 gene (c.1994dup; p.(Asn666Glnfs*41)). This variant has previously been associated with tooth agenesis and polyposis, only. In this case report we describe eight carriers with tooth agenesis and variable clinical findings, including polyps and CRC. Our case provides additional knowledge to the sparse data on genotype–phenotype association related to AXIN2 associated cancer syndrome. Further, our case highlights the importance of analysing an extended CRC and oligodontia/ectodermal dysplasia gene panel including AXIN2 but also raises awareness and discussion about appropriate surveillance program. [ABSTRACT FROM AUTHOR]

Hereditary Polyposis Syndromes are a group of rare, inherited syndromes characterized by the presence of histopathologically specific or numerous intestinal polyps and an increased risk of cancer. Some polyposis syndromes have been known for decades, but the development in genetic technologies has allowed the identification of new syndromes.. The diagnosis entails surveillance from an early age, but universal guideline on how to manage and surveille these new syndromes are lacking. This paper represents a condensed version of the recent guideline (2020) from a working group appointed by the Danish Society of Medical Genetics and the Danish Society of Surgery on recommendations for the surveillance of patients with hereditary polyposis syndromes, including rare polyposis syndromes. [ABSTRACT FROM AUTHOR]

PURPOSE: Historically, cancer predisposition syndromes (CPSs) were rarely established for children with cancer. This nationwide, population-based study investigated how frequently children with cancer had or were likely to have a CPS.METHODS: Children (0–17 years) in Denmark with newly diagnosed cancer were invited to participate in whole-genome sequencing of germline DNA. Suspicion of CPS was assessed according to Jongmans'/McGill Interactive Pediatric OncoGenetic Guidelines (MIPOGG) criteria and familial cancer diagnoses were verified using population-based registries. RESULTS: 198 of 235 (84.3%) eligible patients participated, of whom 94/198 (47.5%) carried pathogenic variants (PVs) in a CPS gene or had clinical features indicating CPS. Twenty-nine of 198 (14.6%) patients harbored a CPS, of whom 21/198 (10.6%) harbored a childhood-onset and 9/198 (4.5%) an adult-onset CPS. In addition, 23/198 (11.6%) patients carried a PV associated with biallelic CPS. Seven of the 54 (12.9%) patients carried two or more variants in different CPS genes. Seventy of 198 (35.4%) patients fulfilled the Jongmans' and/or MIPOGG criteria indicating an underlying CPS, including two of the 9 (22.2%) patients with an adult-onset CPS versus 18 of the 21 (85.7%) patients with a childhood-onset CPS (p = 0.0022), eight of the additional 23 (34.8%) patients with a heterozygous PV associated with biallelic CPS, and 42 patients without PVs. Children with a central nervous system (CNS) tumor had family members with CNS tumors more frequently than patients with other cancers (11/44, p = 0.04), but 42 of 44 (95.5%) cases did not have a PV in a CPS gene. CONCLUSION: These results demonstrate the value of systematically screening pediatric cancer patients for CPSs and indicate that a higher proportion of childhood cancers may be linked to predisposing germline variants than previously supposed. Author summary: Traditionally cancer in childhood have been thought to be–mostly–caused by pure bad luck. In recent years, however, this notion has been challenged by novel findings as both maternal environmental exposure and genetic causes have been identified. With this study we have investigated a national cohort of childhood cancer patients in Denmark. We have mapped family pedigree, made physical examination of the patients, and sequenced their genome, to get a 360-degree understanding of these patients. This revealed that a tenth of all patients carried a genetic variant causative of their cancer development. In addition, almost half of all patients were suspected of carrying a causative genetic variant based on tools that evaluate type of cancer, physical characteristics and family history. It also showed that tools to predict which patients carried a genetic variant did not identify all patients who in fact carried a genetic variant. Overall, roughly half of all patients were suspected of carrying an underlying genetic cause of their cancer, and a tenth had a verified underlying genetic variant predisposing to cancer development in childhood. This could suggest that the amount of childhood cancer cases attributed to genetic factors may be even higher. [ABSTRACT FROM AUTHOR]

Background: Musculocontractural Ehlers–Danlos Syndrome (mcEDS) is a rare connective tissue disorder caused by biallelic loss‐of‐function variants in CHST14 (mcEDS‐CHST14) or DSE (mcEDS‐DSE), both of which result in defective dermatan sulfate biosynthesis. Forty‐one patients with mcEDS‐CHST14 and three patients with mcEDS‐DSE have been described in the literature. Methods: Clinical, molecular, and glycobiological findings in three additional patients with mcEDS‐DSE were investigated. Results: Three patients from two families shared craniofacial characteristics (hypertelorism, blue sclera, midfacial hypoplasia), skeletal features (pectus and spinal deformities, characteristic finger shapes, progressive talipes deformities), skin features (fine or acrogeria‐like palmar creases), and ocular refractive errors. Homozygous pathogenic variants in DSE were found: c.960T>A/p.Tyr320* in patient 1 and c.996dupT/p.Val333Cysfs*4 in patients 2 and 3. No dermatan sulfate was detected in the urine sample from patient 1, suggesting a complete depletion of DS. Conclusion: McEDS‐DSE is a congenital multisystem disorder with progressive symptoms involving craniofacial, skeletal, cutaneous, and cardiovascular systems, similar to the symptoms of mcEDS‐CHST14. However, the burden of symptoms seems lower in patients with mcEDS‐DSE. [ABSTRACT FROM AUTHOR]

Background: Every year more than 800 patients in Denmark are diagnosed with renal cell carcinoma (RCC) of which 3–5% are expected to be part of a hereditary renal cancer syndrome. We performed genetic screening of causative and putative RCC-genes (VHL, FH, FLCN, MET, SDHB, BAP1, MITF, CDKN2B) in RCC-patients suspected of a genetic predisposition. Methods: The cohort consisted of forty-eight Danish families or individuals with early onset RCC, a family history of RCC, a family history of RCC and melanoma or both RCC- and melanoma diagnosis in the same individual. DNA was extracted from peripheral blood samples or cancer-free formalin-fixed paraffin-embedded tissue. Results: One start codon variant of unknown clinical significance (VUS) (c.3G>A, p.Met1Ile) and one missense VUS (c.631A>C, p.Met211Leu) was found in VHL in a patient with RCC-onset at twenty-eight years of age but without other manifestations or family history of von Hippel-Lindau (VHL). Furthermore, in three families we found three different variants in BAP1, one of which was a novel non-segregating missense variant (c.1502G>A, p.Ser501Asn) in a family with two brothers affected with RCC. Finally, we found the known E318K-substitution in MITF in a RCC-affected member of a family with multiple melanomas. No variants were detected in CDKN2B. Conclusion: Although we did find three VUS’s in BAP1 in three families and a pathogenic variant in MITF in one family, pathogenic germline variants in BAP1, MITF or CDKN2B are not frequent causes of hereditary renal cancer in Denmark. It is possible that the high prevalence of risk factors such as male gender, smoking and obesity has influenced the development of cancer in the patients of the current study. Further investigations into putative predisposing genes and risk factors of RCC are necessary to enable better prediction of renal cancer risk or presymptomatic testing of relatives in hereditary renal cancer families. [ABSTRACT FROM AUTHOR]

Dissemination of information on a genetically increased risk should according to guidelines primarily be family-mediated. Incomplete and incorrect information spread has, however, been documented and implies missed possibilities for prevention. In Denmark, the national HNPCC register has been granted an exception to send unsolicited letters with information on hereditary colorectal cancer and an invitation to genetic counseling to members of families with familial and hereditary colorectal cancer. To evaluate this approach, we investigated reactions and attitudes to unsolicited letters in 708 members of families with genetic predisposition and in 1600 individuals from the general population. Support for information letters was expressed by 78% of the family members and by 82% of the general population. Regarding route of information, 90% of family members preferred a letter to no information, 66% preferred information from the hospital rather than from family members and 40% preferred to obtain information from a close family member. Our results suggest that use of unsolicited information letters from the health care system may be a feasible and highly acceptable strategy to disseminate information to families at high risk of colorectal cancer. [ABSTRACT FROM AUTHOR]

TARP syndrome (talipes equinovarus, atrial septal defect, Robin sequence, and persistence of the left superior vena cava) is a rare X‐linked syndrome often resulting in pre‐ or post‐natal lethality in affected males. In 2010, RBM10 was identified as the disease‐causing gene, and we describe the first adult patient with TARP syndrome at age 28 years, hereby expanding the phenotypic spectrum. Our patient had Robin sequence, atrial septal defect, intellectual disability, scoliosis, and other findings previously associated with TARP syndrome. In addition, he had a prominent nose and nasal bridge, esotropia, displacement of lacrimal points in the cranial direction, small teeth, and chin dimple, which are the findings that have not previously been associated with TARP syndrome. Our patient was found to carry a hemizygous c.273_283delinsA RBM10 mutation in exon 4, an exon skipped in three of five protein‐coding transcripts, suggesting a possible explanation for our patient surviving to adulthood. Direct sequencing of maternal DNA indicated possible mosaicism, which was confirmed by massive parallel sequencing. One of two sisters were heterozygous for the mutation. Therefore, we recommend sisters of patients with TARP syndrome be carrier tested before family planning regardless of carrier testing results of the mother. Based on our patient and previously reported patients, we suggest TARP syndrome be considered as a possible diagnosis in males with severe or profound intellectual disability combined with septal heart defect, and Robin sequence, micrognathia, or cleft palate. [ABSTRACT FROM AUTHOR]

The development of hip dysplasia is associated with several risk factors. 1 of these risk factors is gender, since 80% of patients with symptomatic hip dysplasia are females. Another risk factor for hip dysplasia is familial predisposition of hip dysplasia. Several studies indicate that the risk of hip dysplasia is increased with familial prevalence of hip dysplasia. However, little is known about the association between the familial prevalence and gender and the development of hip dysplasia.~Background~Background~The aim of the study was to estimate the prevalence of hip dysplasia among relatives to Danish patients with hip dysplasia operated with periacetabular osteotomy (PAO), and the degree of relationship of affected family members. Furthermore, to assess the association between gender and family predisposition in the same group of patients.~Purpose~Objective~The study is a cross-sectional study, with a descriptive and an analytical part. The study population consists of 676 patients drawn from a clinical database of patients operated with PAO at Aarhus University hospital from 1998 to 2014. Information about gender, operated hip side and age was collected from the clinical PAO database, while information about familial prevalence was collected through questionnaires. The association between gender and familial prevalence of hip dysplasia was presented as the prevalence proportions ratio (PPR), tested by ¿2 test. Stratification was conducted for the variables age and operated hip side, with the Mantel-Haenszels analytical method, and tested for statistical significance by ¿2.~Method~Methods~The familial prevalence of hip dysplasia in the study population was 30% (95% CI, 27%-34%), with 73% reporting affected first-degree relatives. Females have 32% increased risk of familial prevalence of hip dysplasia compared to males, but this difference in risk was not statistically significant (p = 0.10).~Results~Results~The study shows that females have 32% increased familial prevalence of hip dysplasia compared to males, but the increased prevalence was not statistically significant probably due to the low power of the study.~Conclusions~Conclusions [ABSTRACT FROM AUTHOR]

The monogenic Lynch syndrome (LS) is associated with better survival in colorectal cancer (CRC) patients. Whether family history of CRC affects CRC prognosis in general remains unclear. We evaluated overall mortality in a Danish cohort of CRC patients comparing patients with a family history (FH) to those without (FH) with focus on patients from non-syndromic families, thus FH patients were further divided into a non-syndromic group (FH) and a HNPCC/LS group (FH). We included CRC patients diagnosed 1995-1998. First degree relatives were identified using Danish population registries and family history was obtained by linkage to Danish medical registries. 1- and 5-year mortality were evaluated using the Kaplan-Meier method and Cox regression, with adjustment for age, sex, cancer site, cancer stage, and comorbidity. 1196 CRC patients were included in the study, 219 FH patients of whom 197 were FH patients. 1- and 5-year adjusted Mortality Rate Ratios comparing FH patients to FH patients were 0.99 (95 % CI 0.69, 1.42) and 1.07 (95 % CI 0.87, 1.32), respectively. For FH patients, the corresponding MRRs were 1.01 (95 % CI 0.69, 1.47) and 1.15 (95 % CI 0.93, 1.43). For the FH patients MRRs were 0.84 (95 % CI 0.29, 2.44) and 0.66 (95 % CI 0.33, 1.31), respectively. In contrast to the lower mortality in LS patients, other types of familial CRC do not seem to affect the survival after CRC diagnosis. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the value of testing for a 22q11 microdeletion in fetuses with nuchal translucency (NT) above the 99th percentile (>3.5 mm). A 22q11 microdeletion results in the development of 22q11 deletion syndrome, a spectrum of disorders also known as DiGeorge/Velocardiofacial syndrome. A total of 146 pregnancies met the inclusion criteria of NT >3.5 mm between 11+2 and 13+6 weeks' gestation, no structural malformation and normal karyotype. Chorionic villi samples were tested with either multiplex ligation-dependent probe amplification (MLPA) or fluorescent in situ hybridization (FISH) analysis for 22q11 microdeletion. None were diagnosed with the microdeletion. The estimated prevalence of 22q11 microdeletion in these otherwise normal fetuses with increased NT is below 2.7%. [ABSTRACT FROM AUTHOR]

Background: Recent epidemiological evidence shows that colorectal cancer (CRC) continues to occur in carriers of pathogenic mismatch repair (path_MMR) variants despite frequent colonoscopy surveillance in expert centres. This observation conflicts with the paradigm that removal of all visible polyps should prevent the vast majority of CRC in path_MMR carriers, provided the screening interval is sufficiently short and colonoscopic practice is optimal. Methods: To inform the debate, we examined, in the Prospective Lynch Syndrome Database (PLSD), whether the time since last colonoscopy was associated with the pathological stage at which CRC was diagnosed during prospective surveillance. Path_MMR carriers were recruited for prospective surveillance by colonoscopy. Only variants scored by the InSiGHT Variant Interpretation Committee as class 4 and 5 (clinically actionable) were included. CRCs detected at the first planned colonoscopy, or within one year of this, were excluded as prevalent cancers. Results: Stage at diagnosis and interval between last prospective surveillance colonoscopy and diagnosis were available for 209 patients with 218 CRCs, including 162 path_MLH1, 45 path_MSH2, 10 path_MSH6 and 1 path_PMS2 carriers. The numbers of cancers detected within < 1.5, 1.5–2.5, 2.5–3.5 and at > 3.5 years since last colonoscopy were 36, 93, 56 and 33, respectively. Among these, 16.7, 19.4, 9.9 and 15.1% were stage III–IV, respectively (p = 0.34). The cancers detected more than 2.5 years after the last colonoscopy were not more advanced than those diagnosed earlier (p = 0.14). Conclusions: The CRC stage and interval since last colonoscopy were not correlated, which is in conflict with the accelerated adenoma-carcinoma paradigm. We have previously reported that more frequent colonoscopy is not associated with lower incidence of CRC in path_MMR carriers as was expected. In contrast, point estimates showed a higher incidence with shorter intervals between examinations, a situation that may parallel to over-diagnosis in breast cancer screening. Our findings raise the possibility that some CRCs in path_MMR carriers may spontaneously disappear: the host immune response may not only remove CRC precursor lesions in path_MMR carriers, but may remove infiltrating cancers as well. If confirmed, our suggested interpretation will have a bearing on surveillance policy for path_MMR carriers. [ABSTRACT FROM AUTHOR]