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Bachmann-Gagescu, Ruxandra/0000-0002-3571-5271; O'Roak, Brian/0000-0002-4141-0095; Isabella, Christine/0000-0003-0786-7240; Blue, Elizabeth/0000-0002-0633-0305; , Beyhan/0000-0002-9620-5021 WOS: 000358443800002 PubMed: 26092869 Background Joubert syndrome (JS) is a recessive neurodevelopmental disorder characterised by hypotonia, ataxia, cognitive impairment, abnormal eye movements, respiratory control disturbances and a distinctive mid-hindbrain malformation. JS demonstrates substantial phenotypic variability and genetic heterogeneity. This study provides a comprehensive view of the current genetic basis, phenotypic range and gene-phenotype associations in JS. Methods We sequenced 27 JS-associated genes in 440 affected individuals (375 families) from a cohort of 532 individuals (440 families) with JS, using molecular inversion probe-based targeted capture and next-generation sequencing. Variant pathogenicity was defined using the Combined Annotation Dependent Depletion algorithm with an optimised score cut-off. Results We identified presumed causal variants in 62% of pedigrees, including the first B9D2 mutations associated with JS. 253 different mutations in 23 genes highlight the extreme genetic heterogeneity of JS. Phenotypic analysis revealed that only 34% of individuals have a 'pure JS' phenotype. Retinal disease is present in 30% of individuals, renal disease in 25%, coloboma in 17%, polydactyly in 15%, liver fibrosis in 14% and encephalocele in 8%. Loss of CEP290 function is associated with retinal dystrophy, while loss of TMEM67 function is associated with liver fibrosis and coloboma, but we observe no clear-cut distinction between JS subtypes. Conclusions This work illustrates how combining advanced sequencing techniques with phenotypic data addresses extreme genetic heterogeneity to provide diagnostic and carrier testing, guide medical monitoring for progressive complications, facilitate interpretation of genome-wide sequencing results in individuals with a variety of phenotypes and enable gene-specific treatments in the future. Swiss NSFSwiss National Science Foundation (SNSF) [PZ00P3_142404/1]; National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [K23NS45832, K24HD046712, R01NS064077]; March of Dimes Basil O'Connor Starter Scholar Research AwardMarch of Dimes; Arc of Washington Trust Fund; University of Washington Intellectual and Developmental Disabilities Research Center Genetics Core (National Institutes of Health)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [U54HD083091]; National Human Genome Research InstituteUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Human Genome Research Institute (NHGRI); National Heart, Lung and Blood InstituteUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Heart Lung & Blood Institute (NHLBI) [1U54HG006493] RB-G was supported by a Swiss NSF grant Ambizione-SCORE PZ00P3_142404/1. The following authors received support from the National Institutes of Health: M.A.P. K23NS45832, I.A.G. K24HD046712, D.D R01NS064077. D.D. also received funding from a March of Dimes Basil O'Connor Starter Scholar Research Award, The Arc of Washington Trust Fund, and private donations from families of children with Joubert syndrome. The work was also supported by the University of Washington Intellectual and Developmental Disabilities Research Center Genetics Core (National Institutes of Health U54HD083091). Sequencing was provided by the University of Washington Center for Mendelian Genomics (UW CMG) and was funded by the National Human Genome Research Institute and the National Heart, Lung and Blood Institute grant 1U54HG006493 to Drs Debbie Nickerson, JS and Michael Bamshad.

To determine if the addition of group education regarding maternal serum screening and diagnostic testing for aneuploidy and neural tube defects improves patient knowledge and affects the uptake of testing compared to individual education alone.We conducted a prospective study of 443 obstetric patients to assess knowledge of prenatal testing options based on individual provider counseling (n = 331) or provider counseling with supplemental group education (n = 112). We used a chi-square test to compare the number of correct survey answers between the two groups.There was no difference in baseline knowledge. Patients receiving group education showed a statistically significant improvement in knowledge. After initiation of group education, the uptake of maternal serum screening declined while the uptake of amniocentesis remained unchanged.Group education in addition to individual counseling to discuss prenatal testing options appears to be effective in improving knowledge compared to individual provider counseling alone. Improved knowledge may affect uptake of prenatal screening tests due to more informed decision making.

Item does not contain fulltext BACKGROUND: Genomic copy number variants have been shown to be responsible for multiple genetic diseases. Recently, a duplication in septin 9 (SEPT9) was shown to be causal for hereditary neuralgic amyotrophy (HNA), an episodic peripheral neuropathy with autosomal dominant inheritance. This duplication was identified in 12 pedigrees that all shared a common founder haplotype. METHODS AND RESULTS: Based on array comparative genomic hybridisation, we identified six additional heterogeneous tandem SEPT9 duplications in patients with HNA that did not possess the founder haplotype. Five of these novel duplications are intragenic and result in larger transcript and protein products, as demonstrated through reverse transcription-PCR and western blotting. One duplication spans the entire SEPT9 gene and does not generate aberrant transcripts and proteins. The breakpoints of all the duplications are unique and contain regions of microhomology ranging from 2 to 9 bp in size. The duplicated regions contain a conserved 645 bp exon within SEPT9 in which HNA-linked missense mutations have been previously identified, suggesting that the region encoded by this exon is important to the pathogenesis of HNA. CONCLUSIONS: Together with the previously identified founder duplication, a total of seven heterogeneous SEPT9 duplications have been identified in this study as a causative factor of HNA. These duplications account for one third of the patients in our cohort, suggesting that duplications of various sizes within the SEPT9 gene are a common cause of HNA. 01 september 2010

Dobyns, William/0000-0002-7681-2844; VERLOES, Alain/0000-0003-4819-0264 WOS: 000273581000002 PubMed: 19574260 Objective To identify genetic causes of COACH syndrome Background COACH syndrome is a rare autosomal recessive disorder characterised by Cerebellar vermis hypoplasia, Oligophrenia (developmental delay/mental retardation), Ataxia, Coloboma, and Hepatic fibrosis. The vermis hypoplasia falls in a spectrum of mid-hindbrain malformation called the molar tooth sign (MTS), making COACH a Joubert syndrome related disorder (JSRD). Methods In a cohort of 251 families with JSRD, 26 subjects in 23 families met criteria for COACH syndrome, defined as JSRD plus clinically apparent liver disease. Diagnostic criteria for JSRD were clinical findings (intellectual impairment, hypotonia, ataxia) plus supportive brain imaging findings (MTS or cerebellar vermis hypoplasia). MKS3/TMEM67 was sequenced in all subjects for whom DNA was available. In COACH subjects without MKS3 mutations, CC2D2A, RPGRIP1L and CEP290 were also sequenced. Results 19/23 families (83%) with COACH syndrome carried MKS3 mutations, compared to 2/209 (1%) with JSRD but no liver disease. Two other families with COACH carried CC2D2A mutations, one family carried RPGRIP1L mutations, and one lacked mutations in MKS3, CC2D2A, RPGRIP1L and CEP290. Liver biopsies from three subjects, each with mutations in one of the three genes, revealed changes within the congenital hepatic fibrosis/ductal plate malformation spectrum. In JSRD with and without liver disease, MKS3 mutations account for 21/232 families (9%). Conclusions Mutations in MKS3 are responsible for the majority of COACH syndrome, with minor contributions from CC2D2A and RPGRIP1L; therefore, MKS3 should be the first gene tested in patients with JSRD plus liver disease and/or coloboma, followed by CC2D2A and RPGRIP1L. US National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [K23NS45832, K24HD46712, NCRR 5KL2RR025015, R01NS050375]; March of Dimes Endowment for Healthier BabiesMarch of Dimes; Ames Endowment Fund; Allan and Phyllis Treuer Endowed Chair This work was supported by the US National Institutes of Health (grants K23NS45832 to MAP, K24HD46712 to IAG, NCRR 5KL2RR025015 to DD, R01NS050375 to WBD), the March of Dimes Endowment for Healthier Babies (DD, MAP, and IAG), the Ames Endowment Fund at Seattle Children's Hospital (IAG), and the Allan and Phyllis Treuer Endowed Chair (PFC) at Seattle Children's Hospital.

Background: Hereditary neuralgic amyotrophy (HNA) is an autosomal dominant disorder that manifests as recurrent, episodic, painful brachial neuropathies. A gene for HNA maps to chromosome 17q25.3 where mutations in SEPT9 , encoding the septin-9 protein, have been identified. Objective: To determine the frequency and type of mutations in the SEPT9 gene in a new cohort of 42 unrelated HNA pedigrees. Methods: DNA sequencing of all exons and intron-exon boundaries for SEPT9 was carried out in an affected individual in each pedigree from our HNA cohort. Genotyping using microsatellite markers spanning the SEPT9 gene was also used to identify pedigrees with a previously reported founder haplotype. Results: Two missense mutations were found: c.262C>T (p.Arg88Trp) in seven HNA pedigrees and c.278C>T (p.Ser93Phe) in one HNA pedigree. Sequencing of other known exons in SEPT9 detected no additional disease-associated mutations. A founder haplotype, without defined mutations in SEPT9 , was present in seven pedigrees. Conclusions: We provide further evidence that mutation of the SEPT9 gene is the molecular basis of some cases of hereditary neuralgic amyotrophy (HNA). DNA sequencing of SEPT9 demonstrates a restricted set of mutations in this cohort of HNA pedigrees. Nonetheless, sequence analysis will have an important role in mutation detection in HNA. Additional techniques will be required to find SEPT9 mutations in an HNA founder haplotype and other pedigrees.

Background With the increased accuracy of non-invasive prenatal testing (NIPT) based on cell-free DNA (cfDNA) techniques, the likelihood of false-positive screening results has been reduced for high-risk populations. Following a positive screening test, a diagnostic procedure to confirm the result is strongly recommended, although some patients have terminated pregnancies because of a positive NIPT alone. Chorionic villus sampling (CVS), the diagnostic procedure of choice in the first trimester, is not available in all locations. Amniocentesis before 15 weeks, referred to as early amniocentesis (EA), is associated with a 1% rate of talipes and an increased rate of early pregnancy loss compared with CVS. Our objective was to compare the level of risk for euploid pregnancies following a positive NIPT based on the invasive procedure chosen. Method Using data from a 2003 meta-analysis, we estimated the rates of adverse pregnancy outcome in euploid pregnancies based on the positive predictive value (PPV) of NIPT and the invasive procedure used—that is, CVS, EA, or termination of pregnancy (TOP). Results Following NIPT, we found that the rate of adverse fetal outcomes in euploid pregnancies was lower for CVS than for EA at all PPV levels. As the PPV of NIPT increased, the difference in risk between EA and CVS decreased. The risk to euploid pregnancies of TOP was excessive at all PPVs. Conclusion CVS is the recommended diagnostic test in the first trimester because it is safer than EA for the fetus. However, EA is better than no testing when early TOP is planned. Patients should be strongly counselled against TOP without confirmatory testing.

Hereditary neuralgic amyotrophy (HNA) is an autosomal dominant disorder associated with recurrent episodes of focal neuropathy primarily affecting the brachial plexus. Point mutations in the SEPT9 gene have been previously identified as the molecular basis of HNA in some pedigrees. However in many families, including those from North America demonstrating a genetic founder haplotype, no sequence mutations have been detected. We report an intragenic 38 Kb SEPT9 duplication that is linked to HNA in 12 North American families that share the common founder haplotype. Analysis of the breakpoints showed that the duplication is identical in all pedigrees, and molecular analysis revealed that the duplication includes the 645 bp exon in which previous HNA mutations were found. The SEPT9 transcript variants that span this duplication contain two in-frame repeats of this exon, and immunoblotting demonstrates larger molecular weight SEPT9 protein isoforms. This exon also encodes for a majority of the SEPT9 N-terminal proline rich region suggesting that this region plays a role in the pathogenesis of HNA.

Roepman, Ronald/0000-0002-5178-8163; van Beersum, Sylvia E.C./0000-0002-4552-2908; Coene, Karlien/0000-0001-9873-1458; Dibooglu, Sel/0000-0002-3865-5868; Moens, Cecilia/0000-0002-1099-0728; Davis, Erica/0000-0002-2412-8397; Otto, Edgar/0000-0002-2387-9973; Katsanis, Nicholas/0000-0002-2480-0171 WOS: 000261006900002 PubMed: 18950740 Joubert syndrome and related disorders (JSRD) are primarily autosomal-recessive conditions characterized by hypotonia, ataxia, abnormal eye movements, and intellectual disability with a distinctive mid-hindbrain malformation. Variable features include retinal dystrophy, cystic kidney disease, and liver fibrosis. JSRD) are included in the rapidly expanding group of disorders called ciliopathies, because all six gene products implicated in JSRD (NPHP1, AHI1, CEP290, RPGRIP1L, TMEM67, and ARL13B) function in the primary cilium/basal body organelle. By using homozygosity mapping in consanguineous families, we identify loss-of-function Mutations in CC2D2A in JSRD patients with and without retinal, kidney, and liver disease. CC2D2A is expressed in all fetal and adult tissues tested. In ciliated cells, we observe localization of recombinant CC2D2A at the basal body and colocalization with CEP290, whose cognate gene is mutated in multiple hereditary ciliopathies. In addition, the proteins can physically interact in vitro, as shown by yeast two-hybrid and GSTpulldown experiments. A nonsense mutation in the zebrafish CC2D2A ortholog (sentinel) results in pronephric cysts, a hallmark of ciliary dysfunction analogous to human cystic kidney disease. Knockdown of cep290 function in sentinel fish results in a synergistic pronephric cyst phenotype, revealing a genetic interaction between CC2D2A and CEP290 and implicating CC2D2A in cilium/basal body function. These observations extend the genetic spectrum of JSRD and provide a model system for Studying extragenic modifiers in JSRD and other ciliopathies. US National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [K23NS45832]; NCRRUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Center for Research Resources (NCRR) [5KI.2RR025015]; University of Washington Center on Human Development and DisabilityUniversity of Washington [P30HD02274]; Howard Hughes Medical InstituteHoward Hughes Medical Institute; March of Dimes EndowmentMarch of Dimes; Dutch Kidney Foundation [C04.2112]; EVIGENORETEuropean Union (EU) [LSHG-CT-2005 512036]; Netherlands Organisation for Scientific ResearchNetherlands Organization for Scientific Research (NWO) [Vidi-91786396]; [K24HD46712]; [P30ES07033]; [021.001.014] We thank all the participating families with Joubert syndrome and M. Landsverk, R. Howard, J. Adkins, and members of the Moens laboratory for expert technical assistance and helpful discussions. This work was supported by the US National Institutes of Health (grants K23NS45832 to M.A.P, K24HD46712 to I.A.G., NCRR 5KI.2RR025015 to D.D., and P30ES07033 to F.M.F.), the University of Washington Center on Human Development and Disability (P30HD02274 to D.D., M.A.P, and I.A.G.), Howard Hughes Medical Institute (to C.B.M.), the University of Washington Center on Ecogenetics and Environmental Health and the March of Dimes Endowment for Healthier Babies at Children's Hospital in Seattle (to D.D., M.A.P., and I.A.G.), as well as grants from the Dutch Kidney Foundation (C04.2112 to N.V.A.M.K. and R.R.), EVIGENORET (LSHG-CT-2005 512036 to R.R.), and the Netherlands Organisation for Scientific Research (NWO Vidi-91786396 to R.R. and NWO Toptalent-021.001.014 to K.L.M.C.).

Prenatal testing for Down syndrome through the use of non-invasive prenatal testing (NIPT) has been increasingly implemented in clinical practice and a recent cost analysis suggests that NIPT is cost effective when compared to other screening modalities in high risk populations. However, this anaylsis makes many assumptions regarding uptake of testing and pregnancy termination, which cannot be applied to all populations in the United States. Additionally, this cost analysis, which hinges on fewer Down syndrome births, does not align with the goals of prenatal testing to support autonomous and value consistent decisions. NIPT is an expensive new technology and more careful analysis is needed to determine the impact of NIPT on outcomes and overall healthcare costs.