Phenotypic heterogeneity in 22q11.2 deletion syndrome: Copy Number Variants as genetic modifiers for congenital heart disease in a Brazilian cohort.

The clinical heterogeneity in 22q11.2 deletion syndrome (22q11.2DS) underlies complex genetic mechanisms including variants in other regions of the genome, known as genetic modifiers. Congenital heart disease (CHD) is one of the most relevant phenotypes in the syndrome and copy number variants (CNVs) outside the 22q11.2 region could play a role in its variable expressivity. Since those described loci account for a small proportion of the variability, the CNV analysis in new cohorts from different ancestry-based populations constitutes a valuable resource to identify a wider range of modifiers. We performed SNP-array in 117 Brazilian patients with 22q11.2DS, with and without CHD, and leveraged genome-wide CNV analysis. After quality control, we selected 50 CNVs in 38 patients for downstream analysis. CNVs' genetic content and implicated biological pathways were compared between patients with and without CHD. CNV-affected genes in patients with CHD were enriched for several functional terms related to ubiquitination, transcription factor binding sites and miRNA targets, highlighting the complexity of the phenotype's expressivity. Cardiac-related genes were identified in both groups of patients suggesting that increasing risk and protective mechanisms could be involved. These genes and enriched pathways could indicate new modifiers to the cardiac phenotype in 22q11.2DS patients.

Chronic exertional compartment syndrome in the differential diagnosis of peripheral artery disease in older patients with exercise-induced lower limb pain.

OBJECTIVE: Peripheral artery disease (PAD) and chronic exertional compartment syndrome (CECS) both cause exercise-induced lower limb pain. CECS is mostly described in young individuals and may therefore not be considered in older patients with intermittent claudication. The aim of our study was to identify differences in characteristics and symptomatology between patients with CECS and PAD that may help in recognizing CECS in patients ≥50 years with exercise-induced lower limb pain. METHODS: In this case-control study, patients with CECS ≥50 years were selected from a prospectively followed cohort and compared with a sample of newly diagnosed patients with PAD ≥50 years. A questionnaire assessed frequency and severity of lower limb pain, tightness, cramps, muscle weakness, and altered skin sensation at rest and during exercise. RESULTS: At rest, patients with CECS (n = 43, 42% female, 57 years; range, 50-76 years) reported significantly more pain, tightness, muscle weakness and altered skin sensation (all P < .01) than patients with PAD (n = 41, 39% female, 72 years; range, 51-93 years). Having CECS was associated with a significantly higher combined symptom score at rest (P = .02). During exercise, patients with CECS experienced more tightness, muscle weakness and altered sensation (P < .01), but not pain and cramps (P = .36; P = .70). Exercise-induced complaints occurred much later in patients with CECS than in patients with PAD (15 minutes vs 4 minutes; P < .01). Persistence of pain over 4.5 minutes proved most discriminative for the presence of CECS (sensitivity, 95%; specificity, 54%; positive predictive value, 65%). Exercise cessation completely alleviated complaints in all patients with PAD (n = 41) but not in 73% (n = 29) of the patients with CECS. Ongoing discomfort strongly predicted the presence of CECS (sensitivity, 73%; specificity, 100%; positive predictive value, 100%). CONCLUSIONS: Patients with CECS ≥50 years report a symptom pattern that is different from patients with PAD. These differences may aid vascular surgeons in identifying older patients with CECS.

Suboptimal Adherence in Clinical Practice to Guidelines Recommendation to Screen for Lynch Syndrome.

BACKGROUND: Identification of Lynch syndrome (LS) followed by annual/biannual surveillance colonoscopy markedly reduces the risk of developing new colorectal cancer (CRC) among those with LS. AIMS: (1) To determine the current practice of identifying LS in the USA and Canada, and current surveillance and management practices for those diagnosed with LS; (2) to determine whether variances in current practice are physician/region dependent or influenced by ease of access to specialist clinics. METHODS: An online survey request was sent to practicing gastroenterologists through the Canadian Association of Gastroenterology and the American College of Gastroenterology. Fisher's exact tests were performed to determine the factors associated with screening for LS and separately for follow-up, surveillance, and management. RESULTS: A total of 249 participants were recruited, of which 237 were gastroenterologists and included in the analysis. Less than one-third of practicing gastroenterologists indicated that their CRC patients were undergoing screening tests to identify LS. While 42% (65/153) of participants from the USA stated that their patients were undergoing universal LS screening (i.e., among all diagnosed with CRC), only 12% (6/49) of participants from Canada reported this practice (p < 0.001). There was no difference in reported practice between the physicians that do and do not have access to hereditary clinics (35% vs. 34% testing; p = 0.54). Appropriate surveillance interval to look for CRC in patients with LS was recommended by most. CONCLUSION: This survey suggests there is a significant difference in practice between Canada and the USA in regard to identification of LS, with suboptimal practice throughout North America.

Direct-to-consumer carrier screening for cystic fibrosis via a hospital website: a 6-year evaluation.

A Dutch university hospital started offering cystic fibrosis (CF) carrier screening directly to consumers (DTC) through their website in 2010. A 6-year process evaluation was conducted to evaluate the offer. Screening was implemented as intended. However, uptake was lower than expected. Forty-four tests have been requested, partly by couples with a positive family history for CF, which was not the intended target group. Users were generally positive about the screening offer, citing accessibility, ease of testing, anonymity, and perceived shortcomings of regular healthcare as reasons for requesting screening. DTC CF carrier screening via a university hospital website is feasible, but is seldom used. Considering technological advances, continuation of this specific offer is questionable.

Report from the 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Saskatoon, Saskatchewan; 28-29 September 2018.

The 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference was held in Saskatoon, Saskatchewan, 28-29 September 2018. This interactive multidisciplinary conference is attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancers. In addition, invited speakers from other provinces participate. Surgical, medical, and radiation oncologists, and allied health care professionals participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancers.

A Multicentric Brazilian Investigative Study of Copy Number Variations in Patients with Congenital Anomalies and Intellectual Disability.

Genomic imbalances are the most common cause of congenital anomalies (CA) and intellectual disability (ID). The aims of this study were to identify copy number variations (CNVs) in 416 patients with CA and ID from 5 different genetics centers within 4 different states by using the Multiplex Ligation-dependent Probe Amplification (MLPA) technique and to apply the chromosomal microarray (CMA) methodology in selected cases. The samples were analyzed by MLPA kits P064, P036, P070 and P250. Positive results were found in 97/416 (23.3%) patients. CMA was applied in 14 selected cases. In 6/14 (42.85%) patients, CMA detected other copy number variations not detected by the MLPA studies. Although CMA is indispensable for genotype refinement, the technique is still unfeasible in some countries as a routine analysis due to economic and technical limitations. In these cases, clinical evaluation followed by karyotyping and MLPA analysis is a helpful and affordable solution for diagnostic purposes.

Report from the 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Winnipeg, Manitoba; 29-30 September 2017.

The 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Winnipeg, Manitoba, 29-30 September 2017. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

Cri du Chat syndrome: Characteristics of 73 Brazilian patients.

BACKGROUND: Cri du Chat syndrome (CdCS) is a genetic syndrome caused by deletions in the short arm of chromosome 5. Although the main clinical features of CdCS are well known, the neurocognitive and behavioural characteristics of the phenotype are rarely described in detail in the literature. In this study, we analysed the main phenotypic features of CdCS from a parental perspective. METHOD: A questionnaire was sent to 700 Brazilian families that were registered in the Brazilian Association of CdCS. The questions involved specific domains of CdCS, such as pregnancy and birth conditions, recurrence of the disease in the family, current major health problems, and aspects of cognitive development. RESULTS: In total, 73 questionnaires were completed: 44 females and 29 males, ranging from 9.5 months old to 40 years old (mean = 13.8 years; median = 12 years). Most of the parents noticed the typical cat-like cry at birth (94.4%). The age at diagnosis of CdCS ranged from the time of birth to 180 months (mean = 14 months; median = 6 months), while one case was diagnosed during pregnancy. In all of the cases, the diagnosis of CdCS was made by G-banding karyotype analysis. In 66.2% of the cases, the parents underwent cytogenetic investigation. A total of 52.1% of the parents answered that they did not remember what the recurrence risk of CdCS was in their family. The main health problems that were reported were as follows: swallowing problems (80.3%), feeding problems (80.3%), congenital heart disease (31.5%), spine abnormalities (28.8%), and neurological symptoms (20.5%), including seizures (11%). The behavioural problems that were reported were as follows: aggressive behaviour, stereotypies, anxiety, phobias, and genital manipulation/masturbation. Neurodevelopmental delay was reported in all of the cases. Independent walking was achieved in 72.2% of the patients. Approximately 50% of the patients never presented expressive language, and most of the patients are dependent on others for their daily activities. CONCLUSIONS: The questionnaire was a pioneer initiative in the CdCS support group, and the answers used in this study can improve the health care assistance to these patients because they focus attention on the demands from a parental perspective. In addition, nearly half of the families stated that they did not remember information regarding recurrence risk, which reinforces the importance of genetic counselling follow-up and the need for the expansion of genetic services in Brazil.

Preconception carrier screening for multiple disorders: evaluation of a screening offer in a Dutch founder population.

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.

Richieri-Costa-Pereira syndrome: Expanding its phenotypic and genotypic spectrum.

Richieri-Costa-Pereira syndrome is a rare autosomal recessive acrofacial dysostosis that has been mainly described in Brazilian individuals. The cardinal features include Robin sequence, cleft mandible, laryngeal anomalies and limb defects. A biallelic expansion of a complex repeated motif in the 5' untranslated region of EIF4A3 has been shown to cause this syndrome, commonly with 15 or 16 repeats. The only patient with mild clinical findings harbored a 14-repeat expansion in 1 allele and a point mutation in the other allele. This proband is described here in more details, as well as is his affected sister, and 5 new individuals with Richieri-Costa-Pereira syndrome, including a patient from England, of African ancestry. This study has expanded the phenotype in this syndrome by the observation of microcephaly, better characterization of skeletal abnormalities, less severe phenotype with only mild facial dysmorphisms and limb anomalies, as well as the absence of cleft mandible, which is a hallmark of the syndrome. Although the most frequent mutation in this study was the recurrent 16-repeat expansion in EIF4A3, there was an overrepresentation of the 14-repeat expansion, with mild phenotypic expression, thus suggesting that the number of these motifs could play a role in phenotypic delineation.

Experiences of a High-Risk Population with Prenatal Hemoglobinopathy Carrier Screening in a Primary Care Setting: a Qualitative Study.

Carrier screening for hemoglobinopathies (HbPs; sickle cell disease and thalassemia) aims to facilitate autonomous reproductive decision-making. In the absence of a Dutch national HbP carrier screening program, some primary care midwives offer screening on an ad hoc basis. This qualitative descriptive study explores how pregnant women perceive an offer of HbP carrier screening by their midwife. Semi-structured interviews (n = 26) were conducted with pregnant women at risk of being a HbP carrier, and whom were offered screening at their booking appointment in one of two midwifery practices in Amsterdam. The results showed that half of the respondents were familiar with HbPs. Generally, women perceived the offer of HbP carrier screening as positive, and most women (n = 19) accepted screening. Seven declined, of whom two already knew their carrier status. Important reasons to accept screening were to obtain knowledge about their own carrier status and health of their unborn child, and the ease of the procedure. A multistep process of decision-making was observed, as many women did not give follow-up testing (e.g. partner, invasive diagnostics) much consideration while deciding on accepting or declining HbP screening. Women experienced information overload, and preferred receiving the information at a different moment (e.g. before the intake by a leaflet, or preconceptionally). In conclusion, while prenatal HbP carrier screening is perceived as positive, informed decision-making seems to be suboptimal, and both the content and timing of the information provided needs improvement.

Stakeholder perspectives on the implementation of genetic carrier screening in a changing landscape.

BACKGROUND: In most countries, genetic carrier screening is neither offered, nor embedded in mainstream healthcare. Technological developments have triggered a two-fold transition in carrier screening: the expansion from screening one single disorder to many disorders simultaneously, and offering screening universally, regardless of ancestry. This study aims to identify general and population-specific barriers and needs reflected by stakeholders regarding the implementation of carrier screening in a changing landscape. METHODS: Seventeen semi-structured interviews were conducted with Dutch key stakeholders working in the practical and scientific field of carrier screening. The constellation approach was used to categorise barriers and needs into three levels: culture, structure and practice. RESULTS: Barriers on a cultural level include: undecidedness about the desirability of carrier screening, and a lack of priority of screening in mainstream healthcare. On a structural level barriers included: need for organisational structures in healthcare for embedding carrier screening, need for guidelines, financial structures, practical tools for overcoming challenges during counselling, and a need for training and education of both professionals and the public. A lack of demand for screening by the public, and a need for a division of responsibilities were barriers on a practical level. CONCLUSION: The absence of a collective sense of urgency for genetic carrier screening, a lack of organisational structures, and uncertainty or even disagreement about the responsibilities seem to be important barriers in the implementation of carrier screening. Stakeholders therefore suggest that change agents should be formally acknowledged to strategically plan broadening of current initiatives and attune different stakeholders.

Factors for successful implementation of population-based expanded carrier screening: learning from existing initiatives.

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.

Lower urinary tract symptoms in children and adolescents with Williams-Beuren syndrome.

INTRODUCTION: Williams-Beuren syndrome (WBS) is a genetic condition caused by a microscopic deletion in the chromosome band 7q11.23. Individuals with WBS may present with congenital cardiovascular defects, neurodevelopmental disturbances and structural abnormalities of the urinary tract. Lower urinary tract symptoms (LUTS) seem to be frequent in this population, but studies on this topic are scarce and based on small case series. OBJECTIVE: To systematically evaluate the prevalence of lower urinary tract symptoms (LUTS) and the acquisition of bladder control in a large population with WBS. STUDY DESIGN: A cross-sectional study evaluating 87 consecutive patients with WBS; there were 41 girls and 46 boys. Genetic studies confirmed WBS in all patients. Subjects were clinically evaluated with: a history of LUTS obtained from the parents and child, a structured questionnaire of LUTS, a 3-day urinary frequency-volume chart, a quality of life question regarding LUTS, and physical examination. A history regarding the acquisition of bladder control was directly evaluated from the parents. RESULTS: Mean age of patients was 9.0 ± 4.2 years, ranging from 3 to 19 years. Based on the symptoms questionnaire and the frequency-volume chart, 70 patients (80.5%) were symptomatic. The most common symptom was urgency, affecting 61 (70.1%) patients, followed by increased urinary frequency in 60 (68.9%) patients, and urge-incontinence in 53 (60.9%), as shown in Summary Fig. More than half of the children reported nocturnal enuresis, including 61% of the girls and 52% of the boys. Twenty-three patients (25.6%) had a history of urinary tract infections. The mean age for acquisition of dryness during the day was 4.4 ± 1.9 years. Parents of 61 patients (70.1%) acknowledged that LUTS had a significant impact on the quality of life of their children. DISCUSSION: A high prevalence of LUTS was confirmed with a significant negative impact on quality of life in a large population of children and adolescents with WBS. It was shown for the first time that the achievement of daytime bladder control is delayed in children with WBS. Although LUTS are not recognized as one of the leading features of the syndrome, it is believed that it should be considered as a significant characteristic of the clinical diagnosis of WBS. CONCLUSIONS: LUTS are highly prevalent in children and adolescents with WBS and have a significant negative impact on patient's quality of life.

Short Communication Impact of early enzyme-replacement therapy for mucopolysaccharidosis VI: results of a long-term follow-up of Brazilian siblings.

Mucopolysaccharidosis type VI (MPS VI) is an autosomal recessive multisystem lysosomal storage disorder, which is characterized by the deficiency of the enzyme arylsulfatase B encoded by the ARSB gene. Treatment of this disease with enzyme-replacement therapy (ERT) improves the clinical status of and generates hope for MPS VI patients. However, only few reports on patients with MPS VI treated before 5 years of age have been published. Thus, the objective of this study was to compare the clinical parameters of two sisters affected by MPS VI who started ERT at different ages (9 years and 1 year 5 months, respectively) and to determine the most relevant clinical impacts of early treatment after 85 months of evaluation. The treatment was well tolerated by both siblings. ERT in the younger sibling resulted in increased growth, an improved 6-minute walk test, less coarse face, slower progression of cardiac valve disease, and the absence of compressive myelopathy compared to that in her older sister. On the other hand, the older sibling had typical MPS VI phenotypic features before the commencement of ERT. Corneal clouding, clawed hands, and progressive skeletal changes were observed in both siblings despite the treatment. Both siblings displayed reduced frequencies of upper respiratory infections and apnea indices. This study emphasizes that early diagnosis and treatment of MPS VI are critical for a better disease outcome and to enhance the quality of life for these patients.

Do people from the Jewish community prefer ancestry-based or pan-ethnic expanded carrier screening?

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.

Exome sequencing for mucolipidosis III: Detection of a novel GNPTAB gene mutation in a patient with a very mild phenotype.

Mucolipidosis II and III alpha/beta (ML II/III alpha/beta) are rare autosomal recessive lysosomal storage diseases that are caused by a deficiency of UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase, the enzyme responsible for the synthesis of the mannose 6-phosphate targeting signal on lysosomal hydrolases. A Brazilian patient suspected of having a very mild ML III was investigated using whole next-generation sequencing (NGS). Two mutations in the GNPTAB gene were detected and confirmed to be in trans status by parental analysis: c.1208T>C (p.Ile403Thr), previously reported as being pathogenic, and the novel mutation c.1723G>A (p.Gly575Arg). This study demonstrates the effectiveness of using whole NGS for the molecular diagnosis of very mild ML III alpha/beta patients.

Case report. Johanson-Blizzard syndrome: a report of gender-discordant twins with a novel UBR1 mutation.

Johanson-Blizzard syndrome (JBS) is a rare autosomal recessive disorder resulting from loss-of-function mutations in the UBR1 gene. JBS can be easily recognized by its unique clinical presentation (including exocrine pancreatic insufficiency, hypoplasia/aplasia of the alae nasi, congenital scalp defects, sensorineural hearing loss, growth retardation, psychomotor retardation, and anal and genitourinary anomalies). The objective of this study is to report on the first familial case of gender-discordant twins presenting JBS and a novel mutation in the UBR1 gene. We also review literature describing molecularly confirmed cases of JBS. The female twin developed refractory severe diarrhea after the second month of life and died at the age of 3 months. The male twin also developed diarrhea and failure to thrive after the 3 month of life but improved when nutrition support and pancreatic enzyme replacement was started, and he has survived into adolescence. Both patients presented typical clinical features of JBS. A homozygous nonsense mutation (c.3682C>T; p.Q1228X) in UBR1 was confirmed. Severe presentation of JBS usually involves deleterious (nonsense, frameshift, or splice-site) mutations in the UBR1 gene that are thought to completely abolish the expression of a functional protein product, as in this familial case; however, milder presentation of JBS has occasionally been observed with missense mutations in at least 1 of the 2 copies of UBR1, in which there may be residual activity of the product of this gene. Early diagnosis and adequate treatment are crucial for a favorable outcome.

Attitudes of pregnant women and male partners towards non-invasive prenatal testing and widening the scope of prenatal screening.

Non-invasive prenatal testing (NIPT) and its potential to test for multiple disorders has received much attention. This study explores attitudes of women and men towards NIPT, and their views on widening the scope of prenatal testing in a country with a low uptake of prenatal screening (The Netherlands). Five focus groups with low-risk pregnant women (n=28), three focus groups with men (n=19) and 13 interviews with high- and low-risk pregnant women were conducted. Participants felt that current prenatal screening has great disadvantages such as uncertain results and risk of miscarriage from follow-up diagnostics. Characteristics of NIPT (accurate, safe and early testing) could therefore diminish these disadvantages of prenatal screening and help lower the barrier for participation. This suggests that NIPT might allow couples to decide about prenatal testing based mostly on their will to test or not, rather than largely based on fear of miscarriage risk or the uncertainty of results. The lower barrier for participation was also seen as a downside that could lead to uncritical use or pressure to test. Widening the scope of prenatal testing was seen as beneficial for severe disorders, although it was perceived difficult to determine where to draw the line. Participants argued that there should be a limit to the scope of NIPT, avoiding testing for minor abnormalities. The findings suggest that NIPT could enable more meaningful decision-making for prenatal screening. However, to ensure voluntary participation, especially when testing for multiple disorders, safeguards on the basis of informed decision-making will be of utmost importance.

Nager syndrome: confirmation of SF3B4 haploinsufficiency as the major cause.

Nager syndrome belongs to the group of acrofacial dysostosis, which are characterized by the association of craniofacial and limb malformations. Recently, exome sequencing studies identified the SF3B4 gene as the cause of this condition in most patients. SF3B4 encodes a highly conserved protein implicated in mRNA splicing and bone morphogenic protein (BMP) signaling. We performed SF3B4 sequencing in 14 families (18 patients) whose features were suggestive of Nager syndrome and found nine mutations predicted to result in loss-of-function. SF3B4 is the major gene responsible for autosomal dominant Nager syndrome. All mutations reported predict null alleles, therefore precluding genotype-phenotype correlations. Most mutation-negative patients were phenotypically indistinguishable from patients with mutations, suggesting genetic heterogeneity.