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Heterozygous familial hypercholesterolaemia (FH) is a common autosomal dominant inherited metabolic disease with a prevalence of 1 in 500 in most Western countries. People with FH experience an increased risk for coronary artery disease (CAD) and excess mortality especially at a young age. Until recently the diagnosis of FH was based on clinical signs and symptoms alone. These included increased cholesterol concentrations, in particular of LDL-cholesterol, in combination with the presence of tendon xanthoma, corneal arcus, xanthelasmata and a history of early CAD. Frequently FH was diagnosed after a first cardiac event. [ABSTRACT FROM AUTHOR]

Objective: To evaluate phenotype and genotype characteristics of fetuses and children with upper limb anomalies., Method: Retrospective cohort study of a prenatal and postnatal cohort with upper limb anomalies from January 2007 to December 2021 in a Fetal Medicine Unit. Prenatally on ultrasound suspected upper limb anomalies, such as transverse and longitudinal reduction defects, polydactyly, and syndactyly, and postnatally identified children referred to the Congenital Hand Team were evaluated separately., Results: The prenatal group included 199 pregnancies: 64 transverse and 19 longitudinal reduction defects, 103 polydactylies, and 13 cases with syndactyly. The majority of cases with longitudinal reduction defects (n = 10, 52.6%), polydactyly (n = 62, 60.2%), and syndactyly (n = 10, 76.9%) were non-isolated, as opposed to transverse reduction defects, which were generally isolated (n = 41, 64.1%). The postnatal cohort included 362 children with upper limb anomalies with 49 transverse and 22 longitudinal reduction defects, 226 polydactylies, and 65 syndactylies. Chromosomal or monogenic abnormalities were identified in 76/199 (38.2%) cases of the prenatal cohort and in 31/362 (8.6%) cases of the postnatal cohort., Conclusion: Prenatal identification of minor defects of the digits is a challenge, with more postnatal than prenatal cases. The majority of cases with isolated anomalies in both groups had no underlying chromosomal or monogenic cause, nor were they associated with a syndrome, as compared to the non-isolated cases. Conducting structural anomaly scans and genetic counseling are crucial to assess the risk of genetic abnormalities., (© 2024 The Author(s). Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Objectives: An increased nuchal translucency (NT) thickness of ≥ 3.5 mm is a well-established marker for congenital anomalies and adverse pregnancy outcome between 11 and 14 weeks' gestation, but little is known about its performance as a screening tool before 11 weeks. We aimed to investigate, in a prospective setting, whether fetuses with increased NT before 11 weeks are at risk for adverse pregnancy outcome., Methods: This was a prospective cohort study including pregnant women with a viable fetus with NT ≥ 2.5 mm and a crown-rump length (CRL) < 45 mm. All included women were referred to our fetal medicine unit (FMU) and scheduled for a follow-up scan where the NT was remeasured after 1 week when the CRL was > 45 mm. Two groups were evaluated: cases with a normalized NT (< 3.5 mm) and cases with persistently increased NT (≥ 3.5 mm). The cases were monitored until 4 weeks after delivery. The main outcome was a composite adverse outcome of aneuploidy, other genetic disorders, structural anomalies and pregnancy loss. We performed subgroup analyses of NT thickness at inclusion and normalized or persistently increased NT at follow-up., Results: The study included 109 cases, of which 39 (35.8%) had an adverse pregnancy outcome. Of these, 64.1% (25/39) were aneuploid, corresponding to 22.9% (25/109) of the total study population. In the subgroups of NT thickness at inclusion of 2.5-3.4 mm, 3.5-4.4 mm and ≥ 4.5 mm, an adverse outcome was reported in 22.0% (9/41), 40.0% (18/45) and 52.2% (12/23), respectively. In fetuses with a normalized NT and without ultrasound abnormalities at the follow-up scan, the incidence of adverse outcome was 8.5% (5/59), of which 5.1% (3/59) cases were aneuploid., Conclusions: Fetuses with an early increased NT thickness are at considerable risk of an adverse pregnancy outcome, even if the NT normalizes after 11 weeks. Not all congenital anomalies can be diagnosed with routine first-trimester screening, such as non-invasive prenatal testing and/or a first-trimester anomaly scan. Therefore, expectant parents should always be referred to a FMU for detailed ultrasonography. Invasive prenatal testing should be offered if an increased NT of ≥ 2.5 mm is observed before 11 weeks' gestation. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology., (© 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.)

Objective: To determine whether implementation of cell-free DNA (cfDNA) testing for aneuploidy as a first-tier test and subsequent abolition of first trimester combined testing (FCT) affected the first trimester detection (<14 weeks) of certain fetal anomalies., Methods: We performed a geographical cohort study in two Fetal Medicine Units between 2011 and 2020, including 705 fetuses with prenatally detected severe brain, abdominal wall and congenital heart defects. Cases were divided into two groups: before (n = 396) and after (n = 309) cfDNA introduction. The primary outcome was the first trimester detection rate (<14 weeks) overall and for non-chromosomal anomalies solely., Results: Overall, gastroschisis, AVSD and HLHS were detected more often in the first trimester in the before group compared to the after group, respectively 54.5% versus 18.5% (p = 0.004), 45.9% versus 26.9% (p = 0.008) and 30% versus 3.4% (p = 0.005). After exclusion of chromosomal anomalies identifiable through cfDNA testing, the detection of AVSD remained higher in the before group (43.3% vs. 9.5%, p = 0.02), leading to a possible earlier gestation at termination. The termination of pregnancy (TOP) rate did not differ among the groups. In the after group, referrals for suspected anomalies following a dating scan between 11 and 14 weeks significantly increased from 17.4% to 29.1% (p < 0.001)., Conclusion: This study underscores the value of a scan dedicated to fetal anatomy in the first trimester as we observed a decline in the early detection of certain fetal anomalies (detectable in the first trimester) subsequent to the abolition of FCT., (© 2024 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Cherubism is a rare autosomal dominant disease characterized by expansile osteolytic jawbone lesions. The effect and safety of off-label calcitonin treatment during the progressive phase of the disease are not well described. In this retrospective study, we present data on the radiological response and adverse effects of subcutaneously administered calcitonin in a cohort of nine cherubism children (three female, six male). Two of the nine patients underwent two separate treatment courses with a significant off-treatment interval in between; therefore, a total of 11 treatment courses with a mean duration of 17.9 months (range <1 to 35, SD 10.8) were studied. To measure the response, the cumulative volume of cherubism lesions was calculated from available three-dimensional imaging. The primary outcome was the change in the volume of lesions during calcitonin treatment and only assessed for the eight treatment courses with a minimal duration of 6 months. A statistically significant reduction in the mean cumulative volume of lesions was seen regardless of treatment duration. Average volume reduction was highest in the first half year of treatment, with a gradual, ongoing reduction thereafter. For the secondary outcome, the change in the cumulative volume of lesions after treatment cessation was assessed for the seven treatment courses with follow-up imaging available. After six of these seven treatment courses, the cumulative volume increased again but remained undoubtedly smaller than the initial volume at the start of therapy. Adverse effects were assessed for all 11 treatment courses and occurred in 73% of them. Most adverse effects were mild and low grade, with the most severe being one grade 3 symptomatic hypocalcemia requiring hospitalization and early treatment termination. Calcitonin treatment seems effective and tolerable in treating actively progressing cherubism in children. However, further research is required to better understand the pharmacological treatment of cherubism, including also other drugs, dosing, and protocols. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)., (© 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).)

Homozygous familial hypercholesterolemia (HoFH) is a rare, potentially life-limiting, inherited disorder of lipoprotein metabolism characterized by extremely high low-density lipoprotein cholesterol levels. When both parents have heterozygous FH, there is a 25% chance they will conceive a child with HoFH. Here we describe our clinical experience with two such prospective parent couples who were counseled regarding reproductive options and prenatal testing for HoFH. These cases showcase how, in consultation with a molecular geneticist and pediatric cardiologist, parents may be informed of the prognosis and treatment outlook of HoFH based on the FH-variants carried, to ultimately make personal decisions on reproductive options. One couple opted for prenatal testing and termination of pregnancy in case HoFH was found, while the other accepted the risk without testing. We review the available literature on preconception counseling for HoFH and provide practical guidance to clinicians counseling at-risk couples. Optimal counseling of prospective parents may help prevent future physical and psychological problems for both parent and child., Competing Interests: Declaration of Competing Interest AW has received consulting fees from Novartis, is chair of the Steering Committee for the ORION-13 and ORION-16 trial, received payment or honoraria from Amgen, Regeneron and Novartis, and participated on a Data Safety Monitoring Board or Advisory Board of Amgen. GKH reports research grants from the Netherlands Organization for Scientific Research (vidi 016.156.445), CardioVascular Research Initiative, European Union and the Klinkerpad fonds; institutional research support from Aegerion, Amgen, AstraZeneca, Eli Lilly, Genzyme, Ionis, Kowa, Pfizer, Regeneron, Roche, Sanofi, and The Medicines Company; speaker's bureau and consulting fees from Amgen, Aegerion, Sanofi, and Regeneron until April 2019 (fees paid to the academic institution); and part-time employment at Novo Nordisk A/S, Denmark since April 2019. TRT, MDR, JCD, MCvM and IMA declare no conflicts of interest., (Copyright © 2022. Published by Elsevier Inc.)

Purpose: Noninvasive prenatal testing (NIPT) for fetal aneuploidy screening using cell-free DNA derived from maternal plasma can incidentally raise suspicion for cancer. Diagnostic routing after malignancy suspicious-NIPT faces many challenges. Here, we detail malignancy suspicious-NIPT cases, and describe the clinical characteristics, chromosomal aberrations, and diagnostic routing of the patients with a confirmed malignancy. Clinical lessons can be learned from our experience., Methods: Patients with NIPT results indicative of a malignancy referred for tumor screening between April 2017 and April 2020 were retrospectively included from a Dutch nationwide NIPT implementation study, TRIDENT-2. NIPT profiles from patients with confirmed malignancies were reviewed, and the pattern of chromosomal aberrations related to tumor type was analyzed. We evaluated the diagnostic contribution of clinical and genetic examinations., Results: Malignancy suspicious-NIPT results were reported in 0.03% after genome-wide NIPT, and malignancies confirmed in 16 patients (16/48, 33.3%). Multiple chromosomal aberrations were seen in 23 of 48 patients with genome-wide NIPT, and a malignancy was confirmed in 16 patients (16/23, 69.6%). After targeted NIPT, 0.005% malignancy suspicious-NIPT results were reported, in 2/3 patients a malignancy was confirmed. Different tumor types and stages were diagnosed, predominantly hematologic malignancies (12/18). NIPT data showed recurrent gains and losses in primary mediastinal B-cell lymphomas and classic Hodgkin lymphomas. Magnetic resonance imaging and computed tomography were most informative in diagnosing the malignancy., Conclusion: In 231,896 pregnant women, a low percentage (0.02%) of NIPT results were assessed as indicative of a maternal malignancy. However, when multiple chromosomal aberrations were found, the risk of a confirmed malignancy was considerably high. Referral for extensive oncologic examination is recommended, and may be guided by tumor-specific hallmarks in the NIPT profile.

Objectives: In this era of non-invasive-prenatal testing (NIPT), when dating scans are usually performed around 10 weeks of gestation, an increased NT before the official established timeframe (CRL between 45 and 84 mm) may be encountered. Information on management of these pregnancies is limited. Therefore, we evaluated the relationship between an early increased NT and adverse pregnancy outcome. Secondary, we evaluated the rate of chromosomal anomalies that might have been missed in first trimester should solely NIPT be performed as first-tier test, and the rate of adverse pregnancy outcome if NT normalizes before 14 weeks., Methods: We performed a retrospective cohort study that included all pregnancies between January 1, 2007 and June 1, 2020 in Amsterdam UMC locations AMC and VUmc. We included fetuses with a crown-rump length (CRL) < 45 mm (∼11 weeks) and a nuchal translucency (NT) measurement ≥2.5 mm. Fetuses referred with an early increased NT and a major fetal anomaly at the dating scan were excluded, as were cases of parents with a family history of monogenetic disease(s) or recognized carriers of a balanced translocation., Results: We included 120 fetuses of which 66.7% (80/120) had an adverse pregnancy outcome. Congenital anomalies were present in 56.7% (68/120), 45.8% (55/120) had a chromosomal anomaly. The prevalence of congenital anomalies was 30.3% in fetuses with NT 2.5-3.4 mm compared to 66.7% with NT ≥ 3.5 mm (p < 0.001). 16.7% (20/120) had a chromosomal anomaly that might have been missed by conventional NIPT in first trimester. We found an adverse pregnancy outcome of 24% in the group with a normalized NT compared to 78.1% in the group with a persistently increased NT (p < 0.001)., Conclusion: An early increased NT should make the sonographer alert. In this selected cohort, an early increased NT was associated with a high probability of having an adverse pregnancy outcome. Regardless of CRL, we deem that an early increased NT ≥ 3.5 mm warrants referral to a Fetal Medicine Unit for an extensive work-up. NT normalization seems favorable, but a prospective study should define the appropriate work-up for NT in the lower range (2.5-3.4 mm)., (© 2021 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Variants of the C19ORF12-gene have been described in patients with spastic paraplegia type 43 and in patients with mitochondrial membrane protein-associated neurodegeneration (MPAN), a subtype of neurodegeneration associated with brain iron accumulation (NBIA). In both subtypes optic atrophy and neuropathy have been frequently described. This case report describes a patient with bilateral optic atrophy and severe distal muscle weakness based on motor neuropathy without involvement of the central nervous system. Exome sequencing revealed a homozygous pathogenic missense variant (c.187G>C;p.Ala63Pro) of the C19ORF12-gene while iron deposits were absent on repeat MR-imaging of the brain, thus showing that peripheral neuropathy and optic neuropathy can be the sole manifestations of the C19ORF12-related disease spectrum whereby iron accumulation in the brain may be absent., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: The purpose of this study was to explore the diagnostic yield and clinical utility of trio-based rapid whole exome sequencing (rWES) in pregnancies of fetuses with a wide range of congenital anomalies detected by ultrasound imaging., Methods: In this observational study, we analyzed the first 54 cases referred to our laboratory for prenatal rWES to support clinical decision making, after the sonographic detection of fetal congenital anomalies. The most common identified congenital anomalies were skeletal dysplasia (n = 20), multiple major fetal congenital anomalies (n = 17) and intracerebral structural anomalies (n = 7)., Results: A conclusive diagnosis was identified in 18 of the 54 cases (33%). Pathogenic variants were detected most often in fetuses with skeletal dysplasia (n = 11) followed by fetuses with multiple major fetal congenital anomalies (n = 4) and intracerebral structural anomalies (n = 3). A survey, completed by the physicians for 37 of 54 cases, indicated that the rWES results impacted clinical decision making in 68% of cases., Conclusions: These results suggest that rWES improves prenatal diagnosis of fetuses with congenital anomalies, and has an important impact on prenatal and peripartum parental and clinical decision making., (© 2020 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

The Netherlands launched a nationwide implementation study on non-invasive prenatal testing (NIPT) as a first-tier test offered to all pregnant women. This started on April 1, 2017 as the TRIDENT-2 study, licensed by the Dutch Ministry of Health. In the first year, NIPT was performed in 73,239 pregnancies (42% of all pregnancies), 7,239 (4%) chose first-trimester combined testing, and 54% did not participate. The number of trisomies 21 (239, 0.33%), 18 (49, 0.07%), and 13 (55, 0.08%) found in this study is comparable to earlier studies, but the Positive Predictive Values (PPV)-96% for trisomy 21, 98% for trisomy 18, and 53% for trisomy 13-were higher than expected. Findings other than trisomy 21, 18, or 13 were reported on request of the pregnant women; 78% of women chose to have these reported. The number of additional findings was 207 (0.36%); these included other trisomies (101, 0.18%, PPV 6%, many of the remaining 94% of cases are likely confined placental mosaics and possibly clinically significant), structural chromosomal aberrations (95, 0.16%, PPV 32%,) and complex abnormal profiles indicative of maternal malignancies (11, 0.02%, PPV 64%). The implementation of genome-wide NIPT is under debate because the benefits of detecting other fetal chromosomal aberrations must be balanced against the risks of discordant positives, parental anxiety, and a potential increase in (invasive) diagnostic procedures. Our first-year data, including clinical data and laboratory follow-up data, will fuel this debate. Furthermore, we describe how NIPT can successfully be embedded into a national screening program with a single chain for prenatal care including counseling, testing, and follow-up., (Copyright © 2019 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Purpose: Using genome-wide noninvasive prenatal screening (NIPS), we detected a 20-megabase specific deletion starting at 10q25 in eight pregnancies. The deletion could not be confirmed by invasive testing. Since all 10(q25→qter) deletions started close to the FRA10B fragile site in 10q25, we investigated whether the pregnant women were indeed carriers of FRA10B., Methods: We performed NIPS analysis for all autosomes using single-read sequencing. Analysis was done with the WISECONDOR algorithm. Culture of blood lymphocytes with bromodeoxyuridine was used to detect FRA10B expansions. Fluorescence in situ hybridization and array analysis were used to find maternal and/or fetal deletions., Results: We confirmed the presence of a FRA10B expansion in all four tested mothers. Fluorescence in situ hybridization and array analysis confirmed the presence of a maternal mosaic deletion of 10(q25→qter)., Conclusion: The recurring 10(q25→qter) deletion detected with NIPS is a false-positive result caused by a maternal low-level mosaic deletion associated with FRA10B expansions. This has important consequences for clinical follow-up, as invasive procedures are unnecessary. Expanded maternal FRA10B repeats should be added to the growing group of variants in the maternal genome that may cause false-positive NIPS results.

PurposeNoninvasive prenatal screening (NIPS) using cell-free DNA in maternal blood is highly sensitive for detecting fetal trisomies 21, 18, and 13. Using a genome-wide approach, other chromosome anomalies can also be detected. We report on the origin, frequency, and clinical significance of these other chromosome aberrations found in pregnancies at risk for trisomy 21, 18, or 13.MethodsWhole-genome shallow massively parallel sequencing was used and all autosomes were analyzed.ResultsIn 78 of 2,527 cases (3.1%) NIPS was indicative of trisomy 21, 18, or 13, and in 41 (1.6%) of other chromosome aberrations. The latter were of fetal (n = 10), placental (n = 22), maternal (n = 1) or unknown (n = 7). One case lacked cytogenetic follow-up. Nine of the 10 fetal cases were associated with an abnormal phenotype. Thirteen of the 22 (59%) placental aberrations were associated with fetal congenital anomalies and/or poor fetal growth (

It has been well established that histone and DNA modifications are critical to maintaining the equilibrium between pluripotency and differentiation during early embryogenesis. Mutations in key regulators of DNA methylation have shown that the balance between gene regulation and function is critical during neural development in early years of life. However, there have been no identified cases linking epigenetic regulators to aberrant human development and fetal demise. Here, we demonstrate that a homozygous inactivating mutation in the histone deacetylase SIRT6 results in severe congenital anomalies and perinatal lethality in four affected fetuses. In vitro, the amino acid change at Asp63 to a histidine results in virtually complete loss of H3K9 deacetylase and demyristoylase functions. Functionally, SIRT6 D63H mouse embryonic stem cells (mESCs) fail to repress pluripotent gene expression, direct targets of SIRT6, and exhibit an even more severe phenotype than Sirt6-deficient ESCs when differentiated into embryoid bodies (EBs). When terminally differentiated toward cardiomyocyte lineage, D63H mutant mESCs maintain expression of pluripotent genes and fail to form functional cardiomyocyte foci. Last, human induced pluripotent stem cells (iPSCs) derived from D63H homozygous fetuses fail to differentiate into EBs, functional cardiomyocytes, and neural progenitor cells due to a failure to repress pluripotent genes. Altogether, our study described a germline mutation in SIRT6 as a cause for fetal demise, defining SIRT6 as a key factor in human development and identifying the first mutation in a chromatin factor behind a human syndrome of perinatal lethality., (© 2018 Ferrer et al.; Published by Cold Spring Harbor Laboratory Press.)

Technological developments have enabled carrier screening for multiple disorders. This study evaluated experiences with a preconception carrier screening offer for four recessive disorders in a Dutch founder population. Questionnaires were completed by 182 attendees pretesting and posttesting and by 137 non-attendees. Semistructured interviews were conducted with seven of the eight carrier couples. Attendees were mainly informed about the existence of screening by friends/colleagues (49%) and family members (44%). Familiarity with the genetic disorders was high. Knowledge after counseling increased (p < 0.001); however, still 9%, compared to 29% before counseling, wrongly mentioned an increased risk of having an affected child if both parents are carriers of different disorders. Most attendees (97%) recalled their test results correctly, but two couples reported being carrier of another disorder than reported. Overall, 63% felt worried while waiting for results but anxiety levels returned to normal afterwards. In all, 2/39 (5%) carriers felt less healthy. Screened individuals were very satisfied; they did not regret testing (97%) and would recommend testing to others (97%). The majority (94%) stated that couples should always have a pretest consultation, preferably by a genetic counselor rather than their general practitioner (83%). All carrier couples made reproductive decisions based on their results. Main reason for non-attendance was unawareness of the screening offer. With expanded carrier screening, adequately informing couples pretest and posttesting is of foremost importance. Close influencers (family/friends) can be used to raise awareness of a screening offer. Our findings provide lessons for the implementation of expanded carrier screening panels in other communities and other settings.

Increasingly, high-risk pregnant women opt for non-invasive prenatal testing (NIPT) instead of invasive diagnostic testing. Since NIPT is less accurate than invasive testing, a normal NIPT result might leave women less reassured. A questionnaire study was performed among pregnant women with elevated risk for fetal aneuploidy based on first-trimester combined test (risk ≥1:200) or medical history, who were offered NIPT in the nationwide Dutch TRIDENT study. Pre- and post-test questionnaires (n = 682) included measures on: experiences with NIPT procedure, feelings of reassurance, anxiety (State-Trait Anxiety Inventory, STAI), child-related anxiety (PRAQ-R), and satisfaction. The majority (96.1%) were glad to have been offered NIPT. Most (68.5%) perceived the waiting time for NIPT results (mean: 15 days, range 5-32) as (much) too long. Most women with a normal NIPT result felt reassured (80.9%) or somewhat reassured (15.7%). Levels of anxiety and child-related anxiety were significantly lower after receiving a normal NIPT result as compared to the moment of intake (p < 0.001). Women with inadequate health literacy or a medical history (e.g. previous child with trisomy) experienced significantly higher post-test-result anxiety (Mean (M) STAI = 31.6 and 30.0, respectively) compared to those with adequate health literacy (M = 28.6) and no medical history (M = 28.6), indicating these women might benefit from extra information and/or guidance when communicating NIPT test-results. Introducing NIPT as an alternative to invasive testing, led to an offer that satisfied and largely reassured high-risk pregnant women.

Genetically isolated populations exist worldwide. Specific genetic disorders, including rare autosomal recessive disorders may have high prevalences in these populations. We searched for Dutch genetically isolated populations and their autosomal recessive founder mutations. We investigated whether these founder mutations are covered in the (preconception) expanded carrier screening tests of five carrier screening providers. Our results show that the great majority of founder mutations are not covered in these screening panels, and these panels may thus not be appropriate for use in founder populations. It is therefore important to be aware of founder mutations in a population when offering carrier tests.

Background: Carrier screening for autosomal recessive disorders aims to facilitate reproductive decision-making by identifying couples with a 1-in-4 risk in every pregnancy of having an affected child. Except for a few countries or regions, carrier screening is not widely offered and is mostly ancestry-based. Technological advances enable carrier screening for multiple diseases simultaneously allowing universal screening regardless of ancestry (population-based expanded carrier screening). It is important to study how this can be successfully implemented. This study therefore aims to identify critical factors involved in successful implementation, from a user perspective, by learning from already implemented initiatives., Methods: Factors associated with successful implementation were identified by: (i) a literature review and (ii) two case studies; studying experiences with carrier screening in two high-risk communities (a Dutch founder population and the Ashkenazi Jewish population), including a survey among community members., Results: Factors identified were familiarity with (specific) genetic diseases and its availability, high perceived benefits of screening (e.g. screening avoids much suffering), acceptance of reproductive options, perceived risk of being a carrier and low perceived social barriers (e.g. stigmatization). In contrast to the Jewish community, the initial demand for screening in the Dutch founder population did not entirely come from the community itself. However, the large social cohesion of the community facilitated the implementation process., Conclusion: To ensure successful implementation of population-based expanded carrier screening, efforts should be made to increase knowledge about genetic diseases, create awareness and address personal benefits of screening in a non-directive way., (© The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association.)

Objective: To evaluate preferences and decision-making among high-risk pregnant women offered a choice between Non-Invasive Prenatal Testing (NIPT), invasive testing or no further testing., Methods: Nationwide implementation study (TRIDENT) offering NIPT as contingent screening test for women at increased risk for fetal aneuploidy based on first-trimester combined testing (>1:200) or medical history. A questionnaire was completed after counseling assessing knowledge, attitudes and participation following the Multidimensional Measure of Informed Choice., Results: A total of 1091/1253 (87%) women completed the questionnaire. Of these, 1053 (96.5%) underwent NIPT, 37 (3.4%) invasive testing and 1 (0.1%) declined testing. 91.7% preferred NIPT because of test safety. Overall, 77.9% made an informed choice, 89.8% had sufficient knowledge and 90.5% had positive attitudes towards NIPT. Women with intermediate (odds ratio (OR) = 3.51[1.70-7.22], p < 0.001) or high educational level (OR = 4.36[2.22-8.54], p < 0.001) and women with adequate health literacy (OR = 2.60[1.36-4.95], p = 0.004) were more likely to make an informed choice. Informed choice was associated with less decisional conflict and less anxiety (p < 0.001). Intention to terminate the pregnancy for Down syndrome was higher among women undergoing invasive testing (86.5%) compared to those undergoing NIPT (58.4%) (p < 0.001)., Conclusions: The majority of women had sufficient knowledge and made an informed choice. Continuous attention for counseling is required, especially for low-educated and less health-literate women. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd., (© 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.)

Ancestry-based carrier screening in the Ashkenazi Jewish population entails screening for specific autosomal recessive founder mutations, which are rarer among the general population. As it is now technically feasible to screen for many more diseases, the question arises whether this population prefers a limited ancestry-based offer or a pan-ethnic expanded carrier screening panel that goes beyond the diseases that are frequent in their own population, and is offered regardless of ancestry. An online questionnaire was completed by 145 individuals from the Dutch Jewish community (≥ 18 years) between April and July 2014. In total, 64.8% were aware of the existence of ancestry-based carrier screening, and respondents were generally positive about screening. About half (53.8%) preferred pan-ethnic expanded carrier screening, whereas 42.8% preferred ancestry-based screening. Reasons for preferring pan-ethnic screening included 'everyone has a right to be tested', 'fear of stigmatization when offering ancestry-based panels', and 'difficulties with identifying risk owing to mixed backgrounds'. 'Preventing high healthcare costs' was the most important reason against pan-ethnic carrier screening among those in favor of an ancestry-based panel. In conclusion, these findings show that people from the Dutch Jewish community have a positive attitude regarding carrier screening in their community for a wide range of diseases. As costs of expanded carrier screening panels are most likely to drop in the near future, it is expected that these panels will receive more support in the future.

Caudal regression syndrome (CRS) is a rare congenital disorder characterized by developmental abnormalities of caudal spinal segments. To date, the etiology of CRS is unclear; sporadic cases are strongly associated with maternal diabetes, while familiar recurrence is infrequent. We describe in detail the prenatal clinical and sonographic findings of a recently described hereditary caudal regression syndrome, in four fetuses reported to be homozygous for a mutation in the T (brachyury) gene. The syndrome occurred in three consanguineous, but unrelated families, originating from the same geographical area. All affected fetuses had persistence of the notochord in association with abnormal vertebral ossification, sacral agenesis, and bilateral clubfoot. These findings suggest that, in case of prenatal diagnosis of sacral agenesis, an advanced ultrasound examination should assess the vertebral ossification and the rare persistence of the notochord, in order to rule the involvement of the T gene., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.

In a genetically isolated community in the Netherlands four severe recessive genetic disorders occur at relatively high frequency (pontocerebellar hypoplasia type 2 (PCH2), fetal akinesia deformation sequence (FADS), rhizomelic chondrodysplasia punctata type 1 (RCDP1), and osteogenesis imperfecta (OI) type IIB/III. Over the past decades multiple patients with these disorders have been identified. This warranted the start of a preconception outpatient clinic, in 2012, aimed at couples planning a pregnancy. The aim of our study was to evaluate the offer of targeted genetic carrier screening as a method to identify high-risk couples for having affected offspring in this high-risk subpopulation. In one year, 203 individuals (92 couples and 19 individuals) were counseled. In total, 65 of 196 (33.2%) tested individuals were carriers of at least one disease, five (7.7%) of them being carriers of two diseases. Carrier frequencies of PCH2, FADS, RCDP1, and OI were 14.3%, 11.2%, 6.1%, and 4.1% respectively. In individuals with a positive family history for one of the diseases, the carrier frequency was 57.8%; for those with a negative family history this was 25.8%. Four PCH2 carrier-couples were identified. Thus, targeted (preconception) carrier screening in this genetically isolated population in which a high prevalence of specific disorders occurs detects a high number of carriers, and is likely to be more effective compared to cascade genetic testing. Our findings and set-up can be seen as a model for carrier screening in other high-risk subpopulations and contributes to the discussion about the way carrier screening can be offered and organized in the general population., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Approximately 10% of motor neuron disease (MND) patients report a familial predisposition for MND. Autosomal recessively inherited MND is less common and is most often caused by mutations in the superoxide dismutase 1 (SOD1) gene. In 2010, autosomal recessively inherited mutations in the optineurin (OPTN) gene were found in 1% of Japanese patients with sporadic amyotrophic lateral sclerosis (ALS). Autosomal dominantly inherited OPTN mutations have been described as a cause of primary open-angle glaucoma in the Netherlands and were also found in two Dutch sporadic MND patients. We report the first Dutch family with autosomal recessively inherited MND caused by mutations in the OPTN gene.

New mutations for Huntington disease (HD) originate from CAG repeat expansion of intermediate alleles (27-35 CAG). Expansions of such alleles into the pathological range (≥ 36 CAG) have been exclusively observed in paternal transmission. We report the occurrence of a new mutation that defies the paternal expansion bias normally observed in HD. A maternal intermediate allele with 33 CAG repeats expanded in transmission to 48 CAG repeats causing a de novo case of HD in the family. Retrospectively, the mother presented with cognitive decline, but HD was never considered in the differential diagnosis. She was diagnosed with dementia and testing for HD was only performed after her daughter had been diagnosed. This observation of an intermediate allele expanding into the full penetrance HD range after maternal transmission has important implications for genetic counselling of females with intermediate repeats., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Background: The T gene (brachyury gene) is the founding member of the T-box family of transcription factors and is vital for the formation and differentiation of the mesoderm and the axial development of all vertebrates., Results: We report here on four patients from three consanguineous families exhibiting sacral agenesis, a persistent notochordal canal and abnormal ossification of the vertebral bodies, and the identification and characterisation of their underlying genetic defect. Given the consanguineous nature and the similarity of the phenotypes between the three families, we performed homozygosity mapping and identified a common 4.1 Mb homozygous region on chromosome 6q27, containing T, brachyury homologue (mouse) or T. Sequencing of T in the affected individuals led to the identification of a homozygous missense mutation, p.H171R, in the highly conserved T-box. The homozygous mutation results in diminished DNA binding, increased cell growth, and interferes with the normal expression of genes involved in ossification, notochord maintenance and axial mesoderm development., Conclusions: We have identified a shared homozygous mutation in three families in T and linked it to a novel syndrome consisting of sacral agenesis, a persistent notochordal canal and abnormal ossification of the vertebral bodies. We suggest that screening for the ossification of the vertebrae is warranted in patients with sacral agenesis to evaluate the possible causal involvement of T.

Background: Jeune asphyxiating thoracic dystrophy (JATD) is a rare, often lethal, recessively inherited chondrodysplasia characterised by shortened ribs and long bones, sometimes accompanied by polydactyly, and renal, liver and retinal disease. Mutations in intraflagellar transport (IFT) genes cause JATD, including the IFT dynein-2 motor subunit gene DYNC2H1. Genetic heterogeneity and the large DYNC2H1 gene size have hindered JATD genetic diagnosis., Aims and Methods: To determine the contribution to JATD we screened DYNC2H1 in 71 JATD patients JATD patients combining SNP mapping, Sanger sequencing and exome sequencing., Results and Conclusions: We detected 34 DYNC2H1 mutations in 29/71 (41%) patients from 19/57 families (33%), showing it as a major cause of JATD especially in Northern European patients. This included 13 early protein termination mutations (nonsense/frameshift, deletion, splice site) but no patients carried these in combination, suggesting the human phenotype is at least partly hypomorphic. In addition, 21 missense mutations were distributed across DYNC2H1 and these showed some clustering to functional domains, especially the ATP motor domain. DYNC2H1 patients largely lacked significant extra-skeletal involvement, demonstrating an important genotype-phenotype correlation in JATD. Significant variability exists in the course and severity of the thoracic phenotype, both between affected siblings with identical DYNC2H1 alleles and among individuals with different alleles, which suggests the DYNC2H1 phenotype might be subject to modifier alleles, non-genetic or epigenetic factors. Assessment of fibroblasts from patients showed accumulation of anterograde IFT proteins in the ciliary tips, confirming defects similar to patients with other retrograde IFT machinery mutations, which may be of undervalued potential for diagnostic purposes.

A miscarriage is the most frequent complication of a pregnancy. Poor chromosome preparations, culture failure, or maternal cell contamination may hamper conventional karyotyping. Techniques such as chromosomal comparative genomic hybridization (chromosomal-CGH), array-comparative genomic hybridization (array-CGH), fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA) and quantitative fluorescent polymerase chain reaction (QF-PCR) enable us to trace submicroscopic abnormalities. We found the prevalence of chromosome abnormalities in women facing a single sporadic miscarriage to be 45% (95% CI: 38-52; 13 studies, 7012 samples). The prevalence of chromosome abnormalities in women experiencing a subsequent miscarriage after preceding recurrent miscarriage proved to be comparable: 39% (95% CI: 29-50; 6 studies 1359 samples). More chromosome abnormalities are detected by conventional karyotyping compared to FISH or MLPA only (chromosome region specific techniques), and the same amount of abnormalities compared to QF-PCR (chromosome region specific techniques) and chromosomal-CGH and array-CGH (whole genome techniques) only. Molecular techniques could play a role as an additional technique when culture failure or maternal contamination occurs: recent studies show that by using array-CGH, an additional 5% of submicroscopic chromosome variants can be detected. Because of the small sample size as well as the unknown clinical relevance of these molecular aberrations, more and larger studies should be performed of submicroscopic chromosome abnormalities among sporadic miscarriage samples. For recurrent miscarriage samples molecular technique studies are relatively new. It has often been suggested that miscarriages are due to chromosomal abnormalities in more than 50%, but the present review has determined that chromosomal and submicroscopic genetic abnormalities on average are prevalent in maximally half of the miscarriage samples. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Objective: To determine the underlying associations in fetuses with forearm anomalies, and to derive a management strategy to improve prenatal diagnosis and parental counselling., Methods: A retrospective review of fetal medicine unit records to identify all cases with an absent, short or abnormal radius and/or ulna. Cases with a generalised skeletal dysplasia were excluded. Fetal medicine, maternal, neonatal and, where appropriate, histopathological reports, were reviewed., Results: Sixty-six cases were identified. Two were lost to follow-up and subsequently omitted. Chromosomal anomalies accounted for 19 cases (29.7%), genetic syndromes for 19 (29.7%) and isolated forearm defects for 15 cases (23%). A definitive postnatal diagnosis was made in 54 cases (84%). In 45 of the 64 (70%) cases, a correct prenatal diagnosis was made. Cases with bilateral lesions had a significantly higher association with aneuploidy and genetic syndromes, while those with a sonographically isolated unilateral forearm defect had a very low incidence of other underlying pathology., Conclusion: Fetuses with bilateral forearm defects or those with unilateral lesions and other abnormalities detected prenatally have a high incidence of aneuploidy and genetic syndromes. Isolated, unilateral lesions usually have a good prognosis. A management strategy is presented to aid accurate prenatal diagnosis and parental counselling., (© 2012 John Wiley & Sons, Ltd.)

Desbuquois dysplasia (DD) is characterized by antenatal and postnatal short stature, multiple dislocations, and advanced carpal ossification. Two forms have been distinguished on the basis of the presence (type 1) or the absence (type 2) of characteristic hand anomalies. We have identified mutations in calcium activated nucleotidase 1 gene (CANT1) in DD type 1. Recently, CANT1 mutations have been reported in the Kim variant of DD, characterized by short metacarpals and elongated phalanges. DD has overlapping features with spondyloepiphyseal dysplasia with congenital joint dislocations (SDCD) due to Carbohydrate (chondroitin 6) Sulfotransferase 3 (CHST3) mutations. We screened CANT1 and CHST3 in 38 DD cases (6 type 1 patients, 1 Kim variant, and 31 type 2 patients) and found CANT1 mutations in all DD type 1 cases, the Kim variant and in one atypical DD type 2 expanding the clinical spectrum of hand anomalies observed with CANT1 mutations. We also identified in one DD type 2 case CHST3 mutation supporting the phenotype overlap with SDCD. To further define function of CANT1, we studied proteoglycan synthesis in CANT1 mutated patient fibroblasts, and found significant reduced GAG synthesis in presence of β-D-xyloside, suggesting that CANT1 plays a role in proteoglycan metabolism., (© 2012 Wiley Periodicals, Inc.)

Holoprosencephaly is a severe malformation of the brain characterized by abnormal formation and separation of the developing central nervous system. The prevalence is 1:250 during early embryogenesis, the live-born prevalence is 1:16 000. The etiology of HPE is extremely heterogeneous and can be teratogenic or genetic. We screened four known HPE genes in a Dutch cohort of 86 non-syndromic HPE index cases, including 53 family members. We detected 21 mutations (24.4%), 3 in SHH, 9 in ZIC2 and 9 in SIX3. Eight mutations involved amino-acid substitutions, 7 ins/del mutations, 1 frame-shift, 3 identical poly-alanine tract expansions and 2 gene deletions. Pathogenicity of mutations was presumed based on de novo character, predicted non-functionality of mutated proteins, segregation of mutations with affected family-members or combinations of these features. Two mutations were reported previously. SNP array confirmed detected deletions; one spanning the ZIC2/ZIC5 genes (approx. 100 kb) the other a 1.45 Mb deletion including SIX2/SIX3 genes. The mutation percentage (24%) is comparable with previous reports, but we detected significantly less mutations in SHH: 3.5 vs 10.7% (P=0.043) and significantly more in SIX3: 10.5 vs 4.3% (P=0.018). For TGIF1 and ZIC2 mutation the rate was in conformity with earlier reports. About half of the mutations were de novo, one was a germ line mosaic. The familial mutations displayed extensive heterogeneity in clinical manifestation. Of seven familial index patients only two parental carriers showed minor HPE signs, five were completely asymptomatic. Therefore, each novel mutation should be considered as a risk factor for clinically manifest HPE, with the caveat of reduced clinical penetrance.

Objectives: To develop a comprehensive mutation analysis system with a high rate of detection, to develop a tool to predict the chance of detecting a mutation in the L1CAM gene, and to look for genotype-phenotype correlations in the X-linked recessive disorder, L1 syndrome., Methods: DNA from 367 referred patients was analysed for mutations in the coding sequences of the gene. A subgroup of 100 patients was also investigated for mutations in regulatory sequences and for large duplications. Clinical data for 106 patients were collected and used for statistical analysis., Results: 68 different mutations were detected in 73 patients. In patients with three or more clinical characteristics of L1 syndrome, the mutation detection rate was 66% compared with 16% in patients with fewer characteristics. The detection rate was 51% in families with more than one affected relative, and 18% in families with one affected male. A combination of these two factors resulted in an 85% detection rate (OR 10.4, 95% CI 3.6 to 30.1). The type of mutation affects the severity of L1 syndrome. Children with a truncating mutation were more likely to die before the age of 3 than those with a missense mutation (52% vs 8%; p=0.02)., Conclusions: We developed a comprehensive mutation detection system with a detection rate of almost 20% in unselected patients and up to 85% in a selected group. Using the patients' clinical characteristics and family history, clinicians can accurately predict the chance of finding a mutation. A genotype-phenotype correlation was confirmed. The occurrence of (maternal) germline mosaicism was proven.

We present three cases, a 25-year-old woman, a 52-year-old man and a 45-year-old woman, in whom paternal discrepancy (PD) adversely influenced genetic counselling. PD, with an estimated prevalence between 2% and 3%, occurs when a child is identified as being biologically fathered by someone other than the man who believes he is the father. The discovery of PD during genetic testing can cause health problems and psychosocial damage, and can increase costs, as illustrated by our three cases. Opinions vary about whether or not to disclose this sensitive information, and we recommend being as straightforward as possible, while trying to minimize any harm caused. Since genetic techniques that identify PD are improving and increasingly applied, health care providers must be prepared to deal with issues of this nature.

A mutation of the SH3BP2 gene is known to cause cherubism. As there are clinical and histopathological similarities between central giant cell granuloma and cherubism, we made a constitutional DNA analysis of the SH3BP2 gene in four patients with aggressive giant cell granuloma (having one or more of the following features pain, paraesthesia, rapid growth, or root resorption). We found no mutations in the SH3BP2 gene, which indicates that cherubism is a separate entity. However, a somatic mutation in a specific group of cells could cause the focal lesions in giant cell granuloma. Further DNA analysis of the tissue of giant cell granulomas therefore seems indicated.

Elevated levels of tumor necrosis factor-alpha (TNF-alpha), and presence of polymorphisms of the TNFA gene have been implicated in cardiovascular disease pathogenesis. We explored the relationship between polymorphisms in the TNFA gene (-1031C/T, -863C/A -857T/C, -308G/A, -238G/A), protein levels of TNF-alpha and their association to myocardial infarction (MI) using a sample of 1213 post-MI patients and 1561 healthy controls. MI risk was higher among men with elevated TNF-alpha levels, with the highest compared to the lowest TNF-alpha quartile giving a 70% risk increase (OR [95% CI]: 1.7 [1.1; 2.6]). Obese subjects who also had elevated TNF-alpha levels were at even higher risk for MI (OR [95% CI]: 3.4 [2.1; 5.6]). Higher TNF-alpha levels were seen among smokers (but not among non-smokers) carrying the -857T allele. Furthermore, a rare haplotype occurred more frequently among the cases than the controls. Elevated TNF-alpha levels are associated with increased MI risk. Obese subjects with elevated TNF-a levels, and carriers of polymorphisms in or near TNFA are particularly susceptible to the hazards of smoking, results which may have implications for cardiovascular preventive measures.

The aim of this article is threefold. First, we describe the accuracy of people's risk perception who have been screened on familial hypercholesterolemia (FH) in a family-based screening program. Second, we identify factors that modify risk perception. Finally, we show the influence of risk perception on subsequent preventive behavior. The risk perception of 556 screenees (677 participants, overall response = 82%) was measured by postal questionnaires on three occasions: at screening and 3 days and 7 months after the test result was reported to the patient. Presentation of the risk was precategorized and given both as numerical (1 in x) and as verbal probability. In addition, medication use and attitudes toward gene therapy were determined 7 months after screening. On average, the screenees underestimated their numeric risk of having FH and getting a myocardial infarction (MI). Furthermore, FH-positive screenees perceived that they were at greater risk of MI than FH negatives, and screenees with the highest actual risk used medication more, perceived a greater risk, and opted more often for future gene therapy. Risk perception of having FH was influenced by cholesterol level, while MI risk perception was affected by age, education, cholesterol level, and cardiovascular disease (CVD) in the family. We conclude that FH-positive screenees correctly perceive a higher risk of getting a heart attack than do FH-negative screenees. Screenees did not believe that MI was inevitable, and risk perception was associated with both medication use and the intention to opt for gene therapy, but not with other preventive measures. Thus, genetic risk notification seems to be acceptable and does not lead to aversion to preventive behavior., (Copyright 2002 Wiley-Liss, Inc.)

Objectives: To assess the screenees' views on, and the psychological impact of, a family-based genetic screening programme for familial hypercholesterolaemia (FH) and to evaluate non-participation., Methods: Self-administered questionnaires were filled out at the time of screening and after communication of the test result. Non-participants were interviewed by phone., Results: Of the people approached for screening, 2% did not participated. These 2% were not interested, had already been clinically diagnosed, or were afraid of insurance consequences. 677 screenees participated, of whom 215 (32%) tested FH positive. Less than 5% of the screenees were critical of the approach and the information provided. 20% of the screenees expressed feelings of social pressure. Effects on mood were minimal to absent, as were general 'quality of life' effects., Conclusions: Screening for FH is highly acceptable to screenees, although social pressure is prevalent. Only a small percentage of people being approached did not participate.