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PURPOSE To evaluate whether ethnicity affects the risk of full mutation expansion among females heterozygous for FMR1 premutation. METHODS Women who carry the FMR1 premutation alelle of Jewish origin who underwent fragile X prenatal diagnosis between 2011 and 2018 in two medical centers in Israel were included. The heterozygote women and fetuses were analyzed for the number of CGG repeats and AGG interruptions. RESULTS Seven hundred sixty-six subjects were included. Parental ethnicity was fully concordant in 592 cases (Jewish, Ashkenazi, and non-Ashkenazi). Ashkenazi compared with non-Ashkenazi heterozygotes have a significantly higher mean number of CGG repeats (68 ± 8.7, 64 ± 6.4 respectively, P = 0.03) and a lower mean number of AGG interruptions (0.89 ± 0.83, 1.60 ± 1.18 respectively, p = 0.0001). Overall, 56/198 (28.2%) fetuses of Ashkenazi heterozygotes had an expansion to a full mutation compared with 6/98 among the non-Ashkenazi (6.1%) (p = 0.001). Multivariate analysis demonstrated that, in addition to CGG repeats and AGG interruptions (which contributed 68.3% of variance), ethnicity is an independent risk factor for a full mutation expansion (odds ratio [OR] = 2.04, p

Urea cycle disorders (UCDs), including OTC deficiency (OTCD), are life-threatening diseases with a broad clinical spectrum. Early diagnosis and initiation of treatment based on a newborn screening (NBS) test for OTCD with high specificity and sensitivity may contribute to reduction of the significant complications and high mortality. The efficacy of incorporating orotic acid determination into routine NBS was evaluated. Combined measurement of orotic acid and citrulline in archived dried blood spots from newborns with urea cycle disorders and normal controls was used to develop an algorithm for routine NBS for OTCD in Israel. Clinical information and genetic confirmation results were obtained from the follow-up care providers. About 1147986 newborns underwent routine NBS including orotic acid determination, 25 of whom were ultimately diagnosed with a UCD. Of 11 newborns with OTCD, orotate was elevated in seven but normal in two males with early-onset and two males with late-onset disease. Orotate was also elevated in archived dried blood spots of all seven retrospectively tested historical OTCD patients, only three of whom had originally been identified by NBS with low citrulline and elevated glutamine. Among the other UCDs emerge, three CPS1D cases and additional three retrospective CPS1D cases otherwise reported as a very rare condition. Combined levels of orotic acid and citrulline in routine NBS can enhance the detection of UCD, especially increasing the screening sensitivity for OTCD and differentiate it from CPS1D. Our data and the negligible extra cost for orotic acid determination might contribute to the discussion on screening for proximal UCDs in routine NBS.

The penetrance of the p.[Met694Val];[Met694Val] genotype of pyrin in adult FMF patients is close to 100%. Disease penetrance of the p.[Met694Val];[Glu148Gln] genotype (M694V/E148Q), and the heterozygous p.[Met694Val];[=] genotype is unknown. A difference in the penetrance of the latter two may indicate functionality for the p.Glu148Gln variant. We performed a penetrance estimation study using controls and patients of North African Jewish (NAJ) decent. FMF in this population is highly prevalent and mutation frequencies are well known. The ratio between the calculated frequencies of the three genotypes obtained from the control cohort and the actual frequency obtained from the patient cohort were used to determine the penetrance of p.[Met694Val];[Glu148Gln] and p.[Met694Val];[=]. We found a penetrance of 0.135 and 0.008 for p.[Met694Val];[Glu148Gln] and.[Met694Val];[=], respectively. Thus the penetrance of p.[Met694Val];[Glu148Gln] is more than 17 times higher than p.[Met694Val];[=], indicating an active role for p.Glu148Gln when combined with p.Met694Val. This article is protected by copyright. All rights reserved.

Background Filamin C is a cytoskeletal protein expressed in cardiac cells. Nonsense variations in the filamin C gene (FLNC) were associated with dilated and arrhythmogenic cardiomyopathies. Methods and results We identified an intronic variation in FLNC gene (c.3791-1G > C) in three unrelated Ashkenazi Jewish families with variable expression of arrhythmia and cardiomyopathy. cDNA was prepared from a mutation carrier's cultured skin fibroblasts. Quantitative PCR demonstrated a reduction in total FLNC transcript, and no other FLNC splice variants were found. Single-nucleotide polymorphism (SNP) analysis revealed heterozygous variations in the genomic DNA that were not expressed in the messenger RNA. Immunohistochemical analysis of cardiac sections detected a normal distribution of filamin C protein in the heart ventricles. Conclusion The transcript that included the FLNC variant was degraded. Haploinsufficiency in filamin C underlies arrhythmogenic cardiomyopathy with variable symptoms.

Mutations in more than 150 genes are responsible for inherited hearing loss, with thousands of different, severe causal alleles that vary among populations. The Israeli Jewish population includes communities of diverse geographic origins, revealing a wide range of deafness-associated variants and enabling clinical characterization of the associated phenotypes. Our goal was to identify the genetic causes of inherited hearing loss in this population, and to determine relationships among genotype, phenotype, and ethnicity. Genomic DNA samples from informative relatives of 88 multiplex families, all of self-identified Jewish ancestry, with either non-syndromic or syndromic hearing loss, were sequenced for known and candidate deafness genes using the HEar-Seq gene panel. The genetic causes of hearing loss were identified for 60% of the families. One gene was encountered for the first time in human hearing loss: ATOH1 (Atonal), a basic helix-loop-helix transcription factor responsible for autosomal dominant progressive hearing loss in a five-generation family. Our results demonstrate that genomic sequencing with a gene panel dedicated to hearing loss is effective for genetic diagnoses in a diverse population. Comprehensive sequencing enables well-informed genetic counseling and clinical management by medical geneticists, otolaryngologists, audiologists, and speech therapists and can be integrated into newborn screening for deafness.

Exome sequencing (ES) is an important diagnostic tool for individuals with neurodevelopmental disorders (NDD) and/or multiple congenital anomalies (MCA). However, the cost of ES limits the test's accessibility for many patients. We evaluated the yield of publicly funded clinical ES, performed at a tertiary center in Israel, over a 3-year period (2018–2020). Probands presented with (1) moderate-to-profound global developmental delay (GDD)/intellectual disability (ID); or (2) mild GDD/ID with epilepsy or congenital anomaly; and/or (3) MCA. Subjects with normal chromosomal microarray analysis who met inclusion criteria were included, totaling 280 consecutive cases. Trio ES (proband and parents) was the default option. In 252 cases (90.0%), indication of NDD was noted. Most probands were males (62.9%), and their mean age at ES submission was 9.3 years (range 1 month to 51 years). Molecular diagnosis was reached in 109 probands (38.9%), mainly due to de novo variants (91/109, 83.5%). Disease-causing variants were identified in 92 genes, 15 of which were implicated in more than a single case. Male sex, families with multiple-affected members and premature birth were significantly associated with lower ES yield (p

ObjectiveTo describe the WFS1 c.1672C>T; p.R558C missense variant, found in 1.34% of Ashkenazi Jews, that has a relatively mild phenotype and to use computational normal mode analysis (NMA) to explain the genotype-phenotype relationship.MethodsThe clinical, laboratory, and genetic features of 8 homozygotes were collected. A model of the wolframin protein was constructed, and NMA was used to simulate the effect of the variant on protein thermodynamics.ResultsMean age at Wolfram syndrome (WS) diagnosis among homozygotes was 30 years; diabetes (7/8) was diagnosed at mean age 19 years (15–21 years), and bilateral optic atrophy (with MRI evidence of optic/chiasm atrophy) (6/8) at mean age 29 years (15–48 years). The oldest patient (62 years) also had gait difficulties, memory problems, parietal and cerebellar atrophy, and white matter hyperintense lesions. All retained functional vision with independent ambulation and self-care; none had diabetes insipidus or hearing loss. The p.R558C variant caused less impairment of protein entropy than WFS1 variants associated with a more severe phenotype.ConclusionsThe p.R558C variant causes a milder, late-onset phenotype of WS. We report a structural model of wolframin protein based on empirical functional studies and use NMA modeling to show a genotype-phenotype correlation across all homozygotes. Clinicians should be alert to this condition in patients with juvenile diabetes and patients of any age with a combination of diabetes and optic atrophy. Computational NMA has potential benefit for prediction of the genotype-phenotype relationship.

Mutations in more than 150 genes are responsible for inherited hearing loss, with thousands of different, severe causal alleles that vary among populations. The Israeli Jewish population includes communities of diverse geographic origins, revealing a wide range of deafness-associated variants and enabling clinical characterization of the associated phenotypes. Our goal was to identify the genetic causes of inherited hearing loss in this population, and to determine relationships among genotype, phenotype, and ethnicity. Genomic DNA samples from informative relatives of 88 multiplex families, all of self-identified Jewish ancestry, with either non-syndromic or syndromic hearing loss, were sequenced for known and candidate deafness genes using the HEar-Seq gene panel. The genetic causes of hearing loss were identified for 60% of the families. One gene was encountered for the first time in human hearing loss:ATOH1(Atonal), a basic helix-loop-helix transcription factor responsible for autosomal dominant progressive hearing loss in a five-generation family. Our results demonstrate that genomic sequencing with a gene panel dedicated to hearing loss is effective for genetic diagnoses in a diverse population. Comprehensive sequencing enables well-informed genetic counseling and clinical management by medical geneticists, otolaryngologists, audiologists, and speech therapists and can be integrated into newborn screening for deafness.

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Background Adult-onset hereditary motor neuropathies are caused by mutations in multiple genes. Mutations within the vaccinia-related kinase 1 (VRK1) gene were associated with a wide spectrum of recessively inherited motor neuropathies, characterized by childhood to early adulthood age of onset and an occasionally non-lower motor neuron involvement. Methods We describe two patients with adult-onset (aged 48 and 40 years) length-dependent motor neuropathy from unrelated consanguineous families of Moroccan Jewish descent. One also demonstrated mild nocturnal respiratory difficulty and sensory symptoms. Whole-exome sequencing (WES) was performed. Results A homozygous mutation in VRK1 (c.1160G>A (p.Arg387His)), shared by both patients, was identified. This rare mutation segregated with the disease in the two families, and was absent in 120 controls of Jewish Moroccan origin. Conclusions Our findings support VRK1 as a causative gene for adult-onset distal hereditary motor neuropathy, and indicate its relevance for evaluation of individuals with similar motor impairment.

Background: Walker-Warburg phenotype is a severe and lethal autosomal recessive disorder, belonging to a group of congenital malformations defined as abnormal pial basement membrane formation. So far, prenatal diagnosis was considered possible only during late pregnancy. Methods: First trimester assessment of a pregnancy suspected to be affected by Walker-Warburg phenotype, using a high-resolution transvaginal ultrasound probe (6–12 MHz), T2 MR imaging (1.5T), molecular genetics and histopathology. Results: Very early diagnosis of the Walker-Warburg phenotype at 11 weeks of gestation proved possible by depicting the classic signs of this entity, confirmed by molecular genetics, post-abortion MR imaging and histopathology. Conclusion: Advancements in ultrasound equipment and technology, molecular genetics and histopathology have made very early detection of this syndrome possible, thus shedding new light on the natural history of this malformation.

Cancer risks in heterozygous mutation carriers of the ATM, BLM, and FANCC genes are controversial. To shed light on this issue, cancer rates were evaluated by cross referencing asymptomatic Israeli heterozygous mutation carriers in the ATM, BLM, and FANCC genes with cancer diagnoses registered at the Israeli National Cancer Registry (INCR). Comparison of observed to expected Standardized Incidence Rates (SIR) was performed. Overall, 474 individuals participated in the study: 378 females; 25 Arab and 31 Jewish ATM carriers, 152 BLM carriers, and 170 FANCC carriers (all Ashkenazim). Age range at genotyping was 19-53 years (mean + SD 30.6 + 5 years). In addition, 96 males were included; 5, 34, and 57 ATM, BLM, and FANCC mutation carriers, respectively. Over 5-16 years from genotyping (4721 person/years), 15 new cancers were diagnosed in mutation carriers: 5 breast, 4 cervical, 3 melanomas, and one each bone sarcoma, pancreatic, and colorectal cancer. No single cancer diagnosis was more prevalent then expected in all groups combined or per gene analyzed. Specifically breast cancer SIR was 0.02-0.77. We conclude that Israeli ATM, BLM, and FANCC heterozygous mutation carriers are not at an increased risk for developing cancer.

Background TECPR2 was first described as a disease causing gene when the c.3416delT frameshift mutation was found in five Jewish Bukharian patients with similar features. It was suggested to constitute a new subtype of complex hereditary spastic paraparesis (SPG49). Results We report here 3 additional patients from unrelated non-Bukharian families, harboring two novel mutations (c.1319delT, c.C566T) in this gene. Accumulating clinical data clarifies that in addition to intellectual disability and evolving spasticity the main disabling feature of this unique disorder is autonomic-sensory neuropathy accompanied by chronic respiratory disease and paroxysmal autonomic events. Conclusion We suggest that the disease should therefore be classified as a new subtype of hereditary sensory-autonomic neuropathy. The discovery of additional mutations in non-Bukharian patients implies that this disease might be more common than previously appreciated and should therefore be considered in undiagnosed cases of intellectual disability with autonomic features and respiratory symptoms regardless of demographic origin.

Background Maple syrup urine disease is a rare autosomal-recessive aminoacidopathy, caused by deficient branched-chain 2-keto acid dehydrogenase (BCKD), with subsequent accumulation of branched-chain amino acids (BCAAs): leucine, isoleucine and valine. While most cases of MSUD are classic, some 20% of cases are non-classic variants, designated as intermediate- or intermittent-types. Patients with the latter form usually develop normally and are cognitively intact, with normal BCAA levels when asymptomatic. However, intercurrent febrile illness and catabolism may cause metabolic derailment with life-threatening neurological sequelae. Thus, early detection and dietary intervention are warranted in intermittent MSUD. Patients and methods We describe eight patients from four unrelated families, diagnosed with intermittent MSUD. Their presenting symptoms during metabolic crises varied from confusion and decreased consciousness, to ataxia, and acute psychosis. Molecular confirmation of MSUD was pursued via sequencing of the BCKDHA, BCKDHB and DBT genes. Results All affected individuals were found to harbor bi-allelic pathogenic variants in either BCKDHB or DBT. Of the seven variants, four variants in BCKDHB (p.G101D, p. V103A, p. A221D, p. Y195C) and one variant in DBT (p.K427E) were not previously described. Conclusions While newborn screening programs allow for early detection of classic MSUD, cases of the intermittent form might go undetected, and present later in childhood following metabolic derailment, with an array of non-specific symptoms. Our experience with the families reported herein adds to the current knowledge regarding the phenotype and mutational spectrum of this unique inborn error of branched-chain amino acid metabolism, and underscore the high index of suspicion required for its diagnosis.

Introduction: Fragile X syndrome (FXS) is a common form of X-linked intellectual and developmental disability with a prevalence of 1/4000–5000 in males and 1/6000–8000 in females. Most cases of the syndrome result from expansion of a premutation (55–200 CGGs) to a full mutation (>200 CGGs) repeat located in the 5′ untranslated region of the fragile X mental retardation (FMR1) gene. The risk for full mutation expansions increases dramatically with increasing numbers of CGG repeats. Recent studies, however, revealed AGG interruptions within the repeat area function as a “protective factor” decreasing the risk of intergenerational expansion. Materials and Methods: This study was conducted to validate the relevance of AGG analysis for the ethnically diverse Israeli population. To increase the accuracy of our results, we combined results from Israel with those from the New York State Institute for Basic Research in Developmental Disabilities (IBR). To the best of our knowledge this is the largest cohort of different ethnicities to examine risks of unstable transmissions and full mutation expansions among FMR1 premutation carriers. Results: The combined data included 1471 transmissions of maternal premutation alleles: 369 (25.1%) stable and 1,102 (74.9%) unstable transmissions. Full mutation expansions were identified in 20.6% (303/1471) of transmissions. A total of 97.4% (388/397) of transmissions from alleles with no AGGs were unstable, 79.6% (513/644) in alleles with 1 AGG and 46.7% (201/430) in alleles with 2 or more AGGs. The same trend was seen with full mutation expansions where 40% (159/397) of alleles with no AGGs expanded to a full mutation, 20.2% (130/644) for alleles with 1 AGG and only 3.2% (14/430) in alleles with 2 AGGs or more. None of the alleles with 3 or more AGGs expanded to full mutations. Conclusion: We recommend that risk estimates for FMR1 premutation carriers be based on AGG interruptions as well as repeat size in Israel and worldwide.

Background Over 500 epigenetic regulators have been identified throughout the human genome. Of these, approximately 30 chromatin modifiers have been implicated thus far in human disease. Recently, variants in BRPF1, encoding a chromatin reader, have been associated with a previously unrecognized autosomal dominant syndrome manifesting with intellectual disability (ID), hypotonia, dysmorphic facial features, ptosis, and/or blepharophimosis in 22 individuals. Patients and Methods We report a multiply affected nonconsanguineous family of mixed Jewish descent who presented due to ID in three male siblings. Molecular analysis of the family was pursued using whole exome sequencing (WES) and subsequent Sanger sequencing. Results Whole exome sequencing analysis brought to the identification of a novel heterozygous truncating mutation (c.556C>T, p.Q186*) in the BRPF1 gene in the affected siblings and their mother. The four affected individuals showed varying degrees of intellectual disability, distinct facial features including downslanted palpebral fissures, ptosis, and/or blepharophimosis. Their clinical characteristics are discussed in the context of previously reported patients with the BRPF1‐related phenotype. Conclusion The reported family contributes to the current knowledge regarding this unique and newly recognized genetic disorder, and further implicates the role of BRPF1 in human brain development.

Background Familial Mediterranean fever (FMF) is a systemic autoinflammatory monogenic disease. It has been previously reported that FMF patients are prone to develop ischaemic heart disease (IHD), 1 2 mostly due to increased inflammatory activity and endothelial dysfunction. 3 4 However, large-scale information regarding the extent and prognosis of IHD among FMF patients is lacking. Objectives To check whether an association exists between FMF and IHD, and to assess the long-term prognostic significance of IHD among FMF patients using a big data registry with a 15 year follow-up period. Methods Utilising the medical records of Clalit Health Services, the largest HMO in Israel, we extracted a cohort of FMF patients along with their age-and-sex matched controls. Dates of registration in the medical records of FMF, IHD and death, as well as anthropometric information and medical comorbidities were extracted from the database. To compare the distribution of variables across the cohort strata, univariate analysis was performed using Chi-square and student t-test. Multivariate analysis using a logistic regression model was used to find variables associated with IHD. Survival analysis using Cox proportional hazards method and a log-rank test was performed to find variables associated with increased risk of all-cause mortality. Results The cohort included 7,670 FMF patients and 7670 age-and-sex matched controls. The mean age of both groups was 39.1, and both consisted 50.1% females. IHD was observed among 491 FMF patients (6.4%) vs 375 controls (4.89%), p Conclusions IHD is associated with worse prognosis among FMF patients compared to controls. Proper screening methods are recommended to assess whether early identification and treatment may improve life expectancy. References [1] Langevitz P, Livneh A, Neumann L, et al. Prevalence of ischemic heart disease in patients with familial Mediterranean fever. Isr Med Assoc J IMAJ 2001;3:9–12. [2] Twig G, Livneh A, Vivante A, et al. Cardiovascular and metabolic risk factors in inherited autoinflammation. J Clin Endocrinol Metab2014;99:E2123–E2128. doi:10.1210/jc.2014-2096 [3] Akdogan A, Calguneri M, Yavuz B, et al. Are Familial Mediterranean Fever (FMF) patients at increased risk for atherosclerosis? Impaired endothelial function and increased intima media thickness are found in FMF. J Am Coll Cardiol2006;48:2351–2353. doi:10.1016/j.jacc.2006.09.013 [4] Sari I, Karaoglu O, Can G, et al. Early ultrasonographic markers of atherosclerosis in patients with familial Mediterranean fever. Clin Rheumatol2007;26:1467–1473. doi:10.1007/s10067-006-0529-2 Disclosure of Interest None declared

BACKGROUND AnWj is a high-incidence blood group antigen associated with three clinical disorders: lymphoid malignancies, immunologic disorders, and autoimmune hemolytic anemia. The aim of this study was to determine the genetic basis of an inherited AnWj-negative phenotype. METHODS We identified a consanguineous family with two AnWj-negative siblings and 4 additional AnWj-negative individuals without known familial relationship to the index family. We performed exome sequencing in search for rare homozygous variants shared by the two AnWj-negative siblings of the index family and searched for these variants in the four non-related AnWj-negative individuals. RESULTS Exome sequencing revealed seven candidate genes that showed complete segregation in the index family and for which the two AnWj-negative siblings were homozygous. However, the four additional non-related AnWj-negative subjects were homozygous for only one of these variants, rs114851602 (R320Q) in the SMYD1 gene. Considering the frequency of the minor allele, the chance of randomly finding 4 consecutive such individuals is 2.56 × 10-18 . CONCLUSION We present genetic and statistical evidence that the R320Q substitution in SMYD1 underlies an inherited form of the AnWj-negative blood group phenotype. The mechanism by which the mutation leads to this phenotype remains to be determined.

Trichothiodystrophy (TTD), also known as sulfur-deficient brittle hair syndrome, is a rare autosomal recessive multisystem disorder, which manifests with brittle hair, mental retardation, ichthyosis and decreased fertility. Mutations in the TTDN1 (C7orf11) gene have been shown to cause a nonphotosensitive type of trichothiodystrophy. We report of a 19 years old male, born to consanguineous parents of Arab-Muslim descent, who presented due to severe renal failure, but exhibited additional unique features, including developmental delay, mental retardation, splenomegaly, pancytopenia, hypogonadism and brittle hair. Following the clinical diagnosis of nonphotosensitive TTD, sequencing of the coding exons of C7orf11 was performed and revealed the patient to be homozygous for a novel c.505dupA mutation. As the severe renal failure following which the proband was referred to our care is not typically characteristic of this disorder, its significance is discussed. Molecular diagnosis of this highly affected family should enable genetic counseling and prenatal diagnosis for future pregnancies.

Two unrelated patients, presenting with significant global developmental delay, severe progressive microcephaly, seizures, spasticity and thin corpus callosum (CC) underwent trio whole-exome sequencing. No candidate variant was found in any known genes related to the phenotype. However, crossing the data of the patients illustrated that they both manifested pathogenic variants in the SLC1A4 gene which codes the ASCT1 transporter of serine and other neutral amino acids. The Ashkenazi patient is homozygous for a deleterious missense c.766G>A, p.(E256K) mutation whereas the Ashkenazi-Iraqi patient is compound heterozygous for this mutation and a nonsense c.945delTT, p.(Leu315Hisfs*42) mutation. Structural prediction demonstrates truncation of significant portion of the protein by the nonsense mutation and speculates functional disruption by the missense mutation. Both mutations are extremely rare in general population databases, however, the missense mutation was found in heterozygous mode in 1:100 Jewish Ashkenazi controls suggesting a higher carrier rate among Ashkenazi Jews. We conclude that SLC1A4 is the disease causing gene of a novel neurologic disorder manifesting with significant intellectual disability, severe postnatal microcephaly, spasticity and thin CC. The role of SLC1A4 in the serine transport from astrocytes to neurons suggests a possible pathomechanism for this disease and implies a potential therapeutic approach.

Amniocentesis is an invasive procedure performed during pregnancy to determine, among other things, whether the fetus has Down syndrome. It is often preceded by screening, which gives a probabilistic risk assessment. Thus, ample information is conveyed to women with the goal to inform their decisions. This study examined the factors that predict amniocentesis uptake among pregnant women of advanced maternal age (older than 35 years old at the time of childbirth). Participants filled out a questionnaire regarding risk estimates, demographics, and attitudes on screening and pregnancy termination before their first genetic counseling appointment and were followed up to 24 weeks of gestation. Findings show that women's decisions are not always informed by screening results or having a medical indication. Psychological factors measured at the beginning of pregnancy: amniocentesis risk tolerance, pregnancy termination tolerance, and age risk perception affected amniocentesis uptake. Although most women thought that screening for Down syndrome risk would inform their decision, they later stated other reasons for screening, such as preparing for the possibility of a child with special needs. Findings suggest that women's decisions regarding amniocentesis are driven not only by medical factors, but also by a priori attitudes. The authors believe that these should be addressed in the dialogue on women's informed use of prenatal tests.

Purpose To explore the molecular basis of familial, early onset, age-related macular degeneration (AMD) with diverse phenotypes, using whole exome sequencing (WES). Methods We performed WES on four patients (two sibs from two families) manifesting early-onset AMD and searched for disease-causing genetic variants in previously identified macular degeneration related genes. Validation studies of the variants included bioinformatics tools, segregation analysis of mutations within the families and mutation screening in an AMD cohort of patients. Results The index patients were in their 50s when diagnosed and displayed a wide variety of clinical AMD presentations: from limited drusen in the posterior pole to multiple basal-laminar drusen extending peripherally. Severe visual impairment due to extensive geographic atrophy and/or choroidal-neovascularisation was common by the age of 75 years. Approximately, 400 000 genomic variants for each DNA sample were included in the downstream bioinformatics analysis, which ended in the discovery of two novel variants; in one family a single bp deletion was identified in the Hemicentin ( HMCN1 ) gene (c.4162delC), whereas in the other, a missense variant (p.V412M) in the Complement Factor-I ( CFI ) gene was found. Screening for these variants in a cohort of patients with AMD identified another family with the CFI variant. Conclusions This report uses WES to uncover rare genetic variants in AMD. A null-variant in HMCN1 has been identified in one AMD family, and a missense variant in CFI was discovered in two other families. These variants confirm the genetic complexity and significance of rare genetic variants in the pathogenesis of AMD.

Background AIFM1 encodes a mitochondrial flavoprotein with a dual role (NADH oxidoreductase and regulator of apoptosis), which uses riboflavin as a cofactor. Mutations in the X-linked AIFM1 were reported in relation to two main phenotypes: a severe infantile mitochondrial encephalomyopathy and an early-onset axonal sensorimotor neuropathy with hearing loss. In this paper we report two unrelated males harboring AIFM1 mutations (one of which is novel) who display distinct phenotypes including progressive ataxia which partially improved with riboflavin treatment. Methods For both patients trio whole exome sequencing was performed. Validation and segregation were performed with Sanger sequencing. Following the diagnosis, patients were treated with up to 200 mg riboflavin/day for 12 months. Ataxia was assessed by the ICARS scale at baseline, and 6 and 12 months following treatment. Results Patient 1 presented at the age of 5 years with auditory neuropathy, followed by progressive ataxia, vermian atrophy and axonal neuropathy. Patient 2 presented at the age of 4.5 years with severe limb and palatal myoclonus, followed by ataxia, cerebellar atrophy, ophthalmoplegia, sensorineural hearing loss, hyporeflexia and cardiomyopathy. Two deleterious missense mutations were found in the AIFM1 gene: p. Met340Thr mutation located in the FAD dependent oxidoreductase domain and the novel p. Thr141Ile mutation located in a highly conserved DNA binding motif. Ataxia score, decreased by 39% in patient 1 and 20% in patient 2 following 12 months of treatment. Conclusion AIFM1 mutations cause childhood cerebellar ataxia, which may be partially treatable in some patients with high dose riboflavin.

Background Risk for foetal Down syndrome (DS) increases as maternal age increases. Non-invasive screening (maternal serum triple test) for DS is routinely offered to pregnant women to provide risk estimates and suggest invasive amniocentesis for definitive pre-natal diagnosis to high-risk women. Objective We examined women's decision process with regard to pre-natal screening, and specifically, the degree to which they take into account triple serum screening results when considering whether or not to undergo amniocentesis. Design Semi-structured phone interviews were conducted to assess recall of DS screening results, understanding of risk estimates and their effect on women's decision whether to undergo amniocentesis. The study included 60 pregnant Israeli women (half younger than 35 and half advanced maternal age – AMA), with normal DS screening results and no known ultrasound abnormalities. Results Age appeared to determine the decision process. The vast majority of AMA women had amniocentesis, many of them before receiving their DS screening results. Most AMA participants knew that their risk estimate was ‘normal’, but still considered themselves at high risk due to their age. Procedure-related risk (miscarriage) and other factors only had a minor effect on their decision. A minority of younger women had amniocentesis. Younger women mentioned procedure-related risk and having normal screening results as the main factors affecting their decision not to have amniocentesis. Conclusion Age 35 is an anchor for the pre-determination regarding performing or avoiding amniocentesis. AMA women mention ‘age’ as their main reason to have amniocentesis and considered it an independent risk factor.

Huntington disease (HD), an autosomal dominant disorder involving HTT, is characterized by chorea, psychiatric illness and cognitive decline. Diagnosis and age of onset depend on the degree of expansion of the trinucleotide CAG repeat within the gene. The prevalence of HD is known for Europeans but has not been studied in the Israeli population. Between 2006 and 2011 we diagnosed in our adult genetics clinic ten HD probands, nine of whom were Caucasus Jews (CJ) (Azerbaijani), and one Ashkenazi Jewish. We performed haplotype analysis to look for evidence of a founder mutation, and found that of the nine CJ, eight shared the same haplotype that was compatible with the A1 haplogroup. We calculated the coalescence age of the mutation to be between 80 and 150 years. Ninety percent of our HD patients are CJ, as are 27% of the HD patients in Israel, although the CJ comprise only 1.4% of the Israeli population. Our findings suggest a higher prevalence of HD among CJ compared to the general Israeli population and are consistent with a recent founder mutation. We recommend a higher degree of suspicion for HD in CJ with subtle clinical findings.

Background Familial restrictive cardiomyopathy (RCM) caused by a single gene mutation is the least common of the inherited cardiomyopathies. Only a few RCM-causing mutations have been described. Most mutations causing RCM are located in sarcomere protein genes which also cause hypertrophic cardiomyopathy (HCM). Other genes associated with RCM include the desmin and familial amyloidosis genes. In the present study we describe familial RCM with severe heart failure triggered by a de novo mutation in TTN , encoding the huge muscle filament protein titin. Methods and results Family members underwent physical examination, ECG and Doppler echocardiogram studies. The family comprised 6 affected individuals aged 12–35years. Linkage to candidate loci was performed, followed by gene sequencing. Candidate loci/gene analysis excluded 18 candidate genes but showed segregation with a common haplotype surrounding the TTN locus. Sequence analysis identified a de novo mutation within exon 266 of the TTN gene, resulting in the replacement of tyrosine by cysteine. p.Y7621C affects a highly conserved region in the protein within a fibronectin-3 domain, belonging to the A/I junction region of titin. No other disease-causing mutation was identified in cardiomyopathy genes by whole exome sequencing. Conclusions Our study shows, for the first time, that mutations in TTN can cause restrictive cardiomyopathy. The giant filament titin is considered to be a determinant of a resting tension of the sarcomere and this report provides genetic evidence of its crucial role in diastolic function.

Background This study summarizes the results of prenatal diagnosis due to a history of de novo mutation in a previous pregnancy, in a tertiary center in Israel, over a 10‐year period. Methods We sorted all cases of de novo mutations from a pool of 2,260 pregnancies for which prenatal molecular diagnosis was applied, between the years 2008 and 2017. We identified 122 molecular prenatal diagnosis performed for de novo mutations, in 90 women. Results While the total number of yearly prenatal diagnoses stayed stable, a linear increase was detected in the number of cases for which the procedure was done due to a previous de novo mutation: from 3 cases in 2008 to 24 cases in 2017. The most common diseases were Rett syndrome (19), neurofibromatosis Type‐1 (12) and Tuberous sclerosis (5). Recurrence occurred in 3 of the 90 women (3.3%) and hotspot mutations were identified in two genes accounting for 11 cases. We did not find a difference in paternal age at first occurrence of the de novo mutation between the study group and the control group. Conclusion The large increase in the annual number of prenatal diagnoses performed due to a previous pregnancy with a de novo mutation reflects the growing understanding regarding the role of these mutations in the pathogenesis of genetic diseases.

Objective To report and discuss the observation of three fragments on polymerase chain reaction (PCR) in routine carrier screening for fragile X. Methods From 2005 through 2010, 34,500 women underwent prenatal screening for fragile X. PCR was carried out to amplify the repeat segment. The resulting fragments were scanned by a genetic analyser. Results Three PCR peaks representing three different-sized fragments were found in 25 of the 34,500 women (1:1380 or 0.072%). Karyotype analysis was performed in 16 subjects. Full triple X was found in three women, while two had triple X mosaicism. Of the 16 karyotyped women, five (31%) had a finding of XXX (full or mosaic). Conclusions Triple X (full or mosaic) is the most frequently encountered mechanism responsible for three peaks on fragile X PCR testing.

Objective Familial Mediterranean fever (FMF) and Crohn's disease are autoinflammatory disorders, associated with genes (MEFV and NOD2/CARD15, respectively) encoding for regulatory proteins, important in innate immunity, apoptosis, cytokine processing, and inflammation. Although mutations in the MEFV gene were shown to modify Crohn's disease, the role of NOD2/CARD15 gene mutations in the FMF disease phenotype was never studied before. Patients and methods The cohort consisted of 103 consecutive children with FMF, followed in a single referral center. NOD2/CARD15 genotypes were analyzed in all patients and 299 ethnically matched unaffected controls. Demographic data, clinical characteristics, and disease course of FMF patients with and without NOD2/CARD15 mutation were compared. Results A single NOD2/CARD15 mutation was detected in 10 (9.7%) FMF patients and 26 (8.7%) controls. No homozygous or compound heterozygous subjects were discovered in the 2 groups. FMF patients carrying a NOD2/CARD15 mutation had a higher rate of erysipelas-like erythema and acute scrotum attacks, a trend for a higher rate of colchicine resistance and a more severe disease as compared with patients without mutations. Conclusions NOD2/CARD15 mutations are not associated with an increased susceptibility to develop FMF. Nevertheless, the presence of these mutations in FMF patients appears to be associated with a trend to a more severe disease.

Familial dilated cardiomyopathy is a major cause of advanced heart failure and heart transplantation. In most families, the disease-causing mutation is unknown, and relatives should therefore undergo periodic screening to facilitate early diagnosis and therapy. In the present study, we describe a novel titin truncation mutation causing adult-onset familial dilated cardiomyopathy in an Israeli Arab family. The family members underwent physical examination, electrocardiography, and Doppler echocardiography. Linkage to candidate loci was performed, followed by gene sequencing. We identified 13 clinically affected family members (8 men and 5 women, mean age 47 ± 12 years). Compared with their healthy first-degree relatives, the affected relatives had a larger end-diastolic left ventricular dimension (60 ± 10 vs 49 ± 4 mm, p

Objective To increase awareness to the possibility of nemaline myopathy (NM) when abnormal prenatal ultrasound findings appear together with a carrier state for the common exon 55 deletion in the nebulin gene (NEB) of an Ashkenazi Jewish parent. Methods We describe four unrelated pregnancies with abnormal prenatal ultrasound findings resulting in the birth of newborns with NM, where one or both parents were of Ashkenazi Jewish origin. Data was collected retrospectively from the patients' medical files. Molecular analysis of NEB was performed on the DNA from the patients and parents. Results Prenatal ultrasound findings included polyhydramnios, decreased fetal movements, club feet, and arthrogryposis. A biopsy from two of the newborns was consistent with NM. In all of the newborns, the common NEB exon 55 deletion was detected in the heterozygote state and in three of them, a second novel mutation was found. Conclusions Ultrasonographic findings suggestive of a myopathy and a carrier state for the NEB exon 55 deletion in one of the parents should trigger a thorough investigation for NM. The extreme size of NEB imposes great difficulties when searching for a second mutation, especially under the time constraints of an ongoing pregnancy. © 2012 John Wiley & Sons, Ltd.

Objective To assess the frequency of the D1152H mutation in the CFTR gene in normal individuals, in cystic fibrosis (CF) patients and in the setting of prenatal diagnosis. Setting A database analysis of sequential screening results seen at the Sheba Medical Center, Israel, between 2001 and 2010. Methods We retrospectively analyzed the frequency of D1152H in a large cohort of healthy individuals who were screened as part of a routine prenatal care programme, in individuals referred due to CF-related symptoms and in the setting of prenatal diagnosis. Results We found one asymptomatic homozygous female and 195 D1152H carriers among 49,940 healthy individuals screened, establishing a carrier rate of 1:255 for this mutation. We detected D1152H in nine of 103 individuals referred due to CF-related symptoms. Four suffered from respiratory symptoms and five from congenital bilateral absence of the vas deferens (CBAVD). During this period D1152H was detected in three pregnancies, two of which were aborted. Conclusion The increased frequency of D1152H in individuals referred due to CF-related symptoms compared with healthy individuals included in the CF carrier screening programme (P < 0.001) clearly indicates that it is a disease-causing mutation.

Congenital cataracts (CCs), responsible for about one-third of blindness in infants, are a major cause of vision loss in children worldwide. Autosomal-recessive congenital cataracts (arCC) form a clinically diverse and genetically heterogeneous group of disorders of the crystalline lens. To identify the genetic cause of arCC in consanguineous Pakistani families, we performed genome-wide linkage analysis and fine mapping and identified linkage to 3p21-p22 with a summed LOD score of 33.42. Mutations in the gene encoding FYVE and coiled-coil domain containing 1 (FYCO1), a PI(3)P-binding protein family member that is associated with the exterior of autophagosomes and mediates microtubule plus-end-directed vesicle transport, were identified in 12 Pakistani families and one Arab Israeli family in which arCC had previously been mapped to the overlapping CATC2 region. Nine different mutations were identified, including c.3755 delC (p.Ala1252AspfsX71), c.3858_3862dupGGAAT (p.Leu1288TrpfsX37), c.1045 C>T (p.Gln349X), c.2206C>T (p.Gln736X), c.2761C>T (p.Arg921X), c.2830C>T (p.Arg944X), c.3150+1 G>T, c.4127T>C (p.Leu1376Pro), and c.1546C>T (p.Gln516X). Fyco1 is expressed in the mouse embryonic and adult lens and peaks at P12d. Expressed mutant proteins p.Leu1288TrpfsX37 and p.Gln736X are truncated on immunoblots. Wild-type and p.L1376P FYCO1, the only missense mutant identified, migrate at the expected molecular mass. Both wild-type and p. Leu1376Pro FYCO1 proteins expressed in human lens epithelial cells partially colocalize to microtubules and are found adjacent to Golgi, but they primarily colocalize to autophagosomes. Thus, FYCO1 is involved in lens development and transparency in humans, and mutations in this gene are one of the most common causes of arCC in the Pakistani population.

Preimplantation genetic diagnosis using fluorescence in-situ hybridization (PGD-FISH) is currently the most common reproductive solution for translocation carriers. However, this technique usually does not differentiate between embryos carrying the balanced form of the translocation and those carrying the homologous normal chromosomes. We developed a new application of preimplantation genetic haplotyping (PGH) that can identify and distinguish between all forms of the translocation status in cleavage stage embryos prior to implantation.Polymorphic markers were used to identify and differentiate between the alleles that carry the translocation and those that are the normal homologous chromosomes.Embryos from two families of robertsonian translocation carriers were successfully analyzed using polymorphic markers haplotyping.Our preliminary results indicate that the PGH is capable of distinguishing between normal, balanced and unbalanced translocation carrier embryos. This method will improve PGD and will enable translocation carriers to avoid transmission of the translocation and the associated medical complications to offspring.

To characterize the clinical and genetic features of familial Mediterranean fever (FMF).Clinical presentation and MEditerranean FeVer mutation type of all patients with FMF, who first manifested the disease ator =2 years of age were analyzed and compared with patients who first presented with FMF between 2 and 16 years.Of 814 patients with FMF, in 254 patients (31.2%) the first FMF attack was ator =2 years of age, with a mean age at onset of 1.1 +/- 0.8 years. They were compared with 242 patients who presented with their first manifestation of FMF at 2 to 16 years. The clinical manifestations of FMF were comparable in the 2 patient groups, but the delay of diagnosis was longer in patients with early presentation (3.2 +/- 3.2 years vs.1.9 +/- 2.7 years in the group with onset at 2-16 years, P.001). A subgroup of patients (60/254), who were diagnosed ator =2 years had the highest rate of attacks of fever alone as their sole manifestation (40.0% vs 8.4%, P.05), and less peritonitis (45% vs 86.1%, P.05) and pleuritis (3.4% vs 32.9%, P.05). Most of these patients were homozygous for the M694V mutation and were of North African (Sephardic Jewish) extraction.In early life, FMF often begins with an atypical presentation, characterized by attacks of fever alone, and its diagnosis and initiation of treatment is therefore significantly delayed.

Background: The largest cluster of familial Creutzfeldt–Jakob disease (fCJD) exists in Jews of Libyan origin. Familial Mediterranean fever (FMF) is an inflammatory disease also common in this population. Objectives: We hypothesized that FMF, as a pro-inflammatory condition, may affect the course of CJD. Methods: Three hundred and seventy-two consecutive patients diagnosed clinically and genetically as CJD were included in the study. Two hundred and thirty-six had fCJD, and 136 had sporadic disease (sCJD). Review of the patient’s records revealed three patients with FMF–CJD co-morbidity. In addition, 50 DNA samples of patients with CJD were genotyped as homozygote, heterozygote, and non-carriers of the FMF mutation. The demographic and clinical variables of the groups were compared. Results: The three patients with FMF had an earlier age of onset and significantly shorter disease duration than the patients without FMF. Heterozygote carriers did not differ in disease onset and duration from patients without FMF. Conclusions: The shorter disease duration of CJD patients with FMF may indicate the importance of pro-inflammatory factors in the disease.

Objective To define the molecular basis of familial Mediterranean fever (FMF) in patients with only 1 mutation in the MEFV gene. Methods Genetic analysis was performed in 20 FMF patients, including full sequencing of complementary DNA (cDNA) samples and multiplex ligation-dependent probe amplification analysis. In patients with first-degree relatives with FMF, haplotype analysis was also performed. Results A second mutation was found in 2 patients. In the other 18 patients, we could not identify additional mutations, large genomic deletions, or duplications. Analysis of single-nucleotide polymorphisms along the cDNA ruled out a lack of expression of 1 of the alleles. In 2 of the 3 families in which more than 1 sibling had FMF, we showed that the affected siblings inherited a different MEFV allele from the parent who did not have the MEFV mutation. Conclusion These findings are highly consistent with the existence of a clinical phenotype among some patients who are heterozygous for FMF and could explain the vertical transmission in some families. A single mutation in the MEFV gene may be much more common than was previously thought and may include up to 25% of patients who are diagnosed as having FMF.

Brittle cornea syndrome (BCS) is an autosomal-recessive disorder characterized by a thin cornea that tends to perforate, causing progressive visual loss and blindness. Additional systemic symptoms such as joint hypermotility, hyperlaxity of the skin, and kyphoscoliosis place BCS among the connective-tissue disorders. Previously, we assigned the disease gene to a 4.7 Mb interval on chromosome 16q24. In order to clone the BCS gene, we first narrowed the disease locus to a 2.8 Mb interval and systematically sequenced genes expressed in connective tissue in this chromosomal segment. We have identified two frameshift mutations in the Zinc-Finger 469 gene (ZNF469). In five unrelated patients of Tunisian Jewish ancestry, we found a 1 bp deletion at position 5943 (5943 delA), and in an inbred Palestinian family we detected a single-nucleotide deletion at position 9527 (9527 delG). The function of ZNF469 is unknown. However, a 30% homology to a number of collagens suggests that it could act as a transcription factor involved in the synthesis and/or organization of collagen fibers.

Somech and colleagues identify two new mutations in STN1 that causes Coats plus syndrome and telomere abnormalities in human, recapitulated in a zebra fish model., The analysis of individuals with telomere defects may shed light on the delicate interplay of factors controlling genome stability, premature aging, and cancer. We herein describe two Coats plus patients with telomere and genomic defects; both harbor distinct, novel mutations in STN1, a member of the human CTC1–STN1–TEN1 (CST) complex, thus linking this gene for the first time to a human telomeropathy. We characterized the patients’ phenotype, recapitulated it in a zebrafish model and rescued cellular and clinical aspects by the ectopic expression of wild-type STN1 or by thalidomide treatment. Interestingly, a significant lengthy control of the gastrointestinal bleeding in one of our patients was achieved by thalidomide treatment, exemplifying a successful bed-to-bench-and-back approach.

Background A primary goal of amniocentesis is the detection of trisomy 21 (Down syndrome- DS) in the fetus. This procedure involves a small risk of miscarriage. As the risk of DS increases with maternal age, screening tests (maternal serum triple test and others) and age are used to generate a risk assessment, and amniocentesis is offered to women with high risk. In Israel, amniocentesis is government funded for women of advanced maternal age (AMA, i.e., ≥35 years), even if their risk assessment is low. The purpose of this study was to explore the reasons AMA women undergo amniocentesis, their knowledge about risk estimates, and to evaluate whether their decision is informed. Methods Shortly after undergoing amniocentesis, 42 consecutive women without a medical indication for amniocentesis other than age, completed a questionnaire that assessed their knowledge and opinions regarding screening tests, pregnancy termination, amniocentesis risks and the factors that affected their decision. Results Women rarely deliberated before undergoing amniocentesis. One third of those who had the screening test did not wait for the results before undergoing amniocentesis. Only one third of those who received the screening results remembered their risk estimation before going ahead with amniocentesis. Almost half (41 %) cited “age” as their main reason for undergoing amniocentesis, though only 44 % of these women could recall their age related DS risk. Sixty percent estimated their DS risk as low or very low but still had amniocentesis. Most participants (74 %) stated that they would consider termination of the pregnancy if the fetus was diagnosed with an intellectual deficit. Conclusions These results cast doubt on whether AMA women’s decision to undergo amniocentesis is based on risk estimates, as women seem to disregard risk estimates, and sometimes not even wait for them when making the decision. The policy of funding amniocentesis solely on the basis of age may have led to the conception that being over 35 alone is sufficient reason to undergo amniocentesis. This finding should inform policy makers, as it raises questions about the link between public funding and the choices of individual women, and has implications for healthcare expenditures.

Monilethrix is a structural defect of the hair shaft usually inherited in an autosomal dominant fashion and caused by mutations in the hHb1, hHb3, and hHb6 keratin genes. Autosomal recessive inheritance in this disease has been sporadically reported. We encountered 12 Jewish families from Iraq, Iran, and Morocco with microscopic findings of monilethrix, but with no evidence of vertical transmission. Since no mutations were found in these three hair keratin genes, we examined nine chromosomal regions containing gene clusters encoding skin and hair genes. On chromosome 18q, a common haplotype in the homozygous state was found among all seven Iraqi patients, but not in 20 controls (P

We hypothesized that there is an association between the angiotensin I-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism with the variability in exercise heat tolerance in humans. Fifty-eight Caucasian men were exposed to a 2-h exercise heat-tolerance test. We analyzed the association between their heat-tolerance levels with the ACE DD ( n = 25) and I+ ( n = 33) genotypes and with various anthropometrical parameters and aerobic fitness. It was found that the relative changes in body core temperature, heat storage, and heart rate during the 120-min exposure to exercise heat stress was consistently lower in the I+ genotype group compared with the DD genotype group (0.8 ± 0.2 vs. 1 ± 0.1°C, P < 0.05; 17.7 ± 1.8 vs. 19.8 ± 1.3 W/M2, P < 0.05; and 33 ± 7 vs. 44 ± 5 beats/min, respectively, P = 0.06). No significant association was found between heat strain response and the anthropometrical measurements or aerobic fitness in the various genotype groups. We suggest that the ACE I+ polymorphism may be considered as a possible candidate marker for increased heat tolerance.

Catecholamine-induced polymorphic ventricular tachycardia (CPVT), a rare disease that occurs in subjects without obvious organic heart disease, is characterized by episodes of syncope, seizures, or sudden death in response to physiologic or emotional stress. This report reviews evidence that a missense mutation in the CASQ2 gene is associated with autosomal-recessive CPVT.

Many factors predict the intention to disclose genetic information to relatives. The article examines the impact of patients' socio-demographic factors on their intention to disclose genetic testing results to their relatives. Data were collected in eight genetic clinics in Israel. Patients were requested to fill in a questionnaire after counseling. A convenience sample of 564 participants who visited these clinics was collected for a response rate of 85 %. Of them, 282 participants came for susceptibility testing for hereditary cancers (cancer group), and 282 for genetic screening tests (prenatal group). In the cancer group, being secular and having more years of education correlated positively with the intention to disclose test results to relatives. In the prenatal group, being married and female correlated positively with the intention to disclose. In the cancer group, being religious and with less years of education correlated positively with the view that the clinician should deliver the results to the family. In the prenatal group, being male and unmarried correlated positively with this belief. In both groups, being of young age correlated with the perception that genetic information is private. Varied sociodemographic factors affect the intention to inform family members. Thus, knowing the social background of patients will shed light on people's attitudes to genetic information and will help clinicians provide effective counseling in discussions with patients about the implications of test results for relatives.

BACKGROUND: Polyarteritis nodosa is a systemic necrotizing vasculitis with a pathogenesis that is poorly understood. We identified six families with multiple cases of systemic and cutaneous polyarteritis nodosa, consistent with autosomal recessive inheritance. In most cases, onset of the disease occurred during childhood. METHODS: We carried out exome sequencing in persons from multiply affected families of Georgian Jewish or German ancestry. We performed targeted sequencing in additional family members and in unrelated affected persons, 3 of Georgian Jewish ancestry and 14 of Turkish ancestry. Mutations were assessed by testing their effect on enzymatic activity in serum specimens from patients, analysis of protein structure, expression in mammalian cells, and biophysical analysis of purified protein. RESULTS: In all the families, vasculitis was caused by recessive mutations in CECR1, the gene encoding adenosine deaminase 2 (ADA2). All the Georgian Jewish patients were homozygous for a mutation encoding a Gly47Arg substitution, the German patients were compound heterozygous for Arg169Gln and Pro251Leu mutations, and one Turkish patient was compound heterozygous for Gly47Val and Trp264Ser mutations. In the endogamous Georgian Jewish population, the Gly47Arg carrier frequency was 0.102, which is consistent with the high prevalence of disease. The other mutations either were found in only one family member or patient or were extremely rare. ADA2 activity was significantly reduced in serum specimens from patients. Expression in human embryonic kidney 293T cells revealed low amounts of mutant secreted protein. CONCLUSIONS: Recessive loss-of-function mutations of ADA2, a growth factor that is the major extracellular adenosine deaminase, can cause polyarteritis nodosa vasculopathy with highly varied clinical expression. (Funded by the Shaare Zedek Medical Center and others.).

SummaryPremature ovarian failure and diminished ovarian reserve have been noted both in female BRCA1/BRCA2 mutation carriers and in carriers of the Fragile X syndrome FMR1 gene CGG repeat size premutation. Based on the observation that BRCA mutation carriers do not harbour long CGG repeats in the FMR1 gene, it was hypothesized that BRCA-associated premature ovarian failure is mediated via FMR1. To test this notion, we evaluated the distribution of constitutional FMR1 genotypes in 188 BRCA1/BRCA2 mutation-positive Jewish Ashkenazi women and 15 708 female, mostly Ashkenazi controls in Israel. BRCA1/BRCA2 mutation carriers displayed a unique distribution of FMR1 genotypes compared with controls (p = 0·018) with a prominence of the shorter CGG alleles (BRCA carriers when comparing cancer free (n = 95) and breast cancer affected women (n = 93) (p = 0·43). In conclusion, BRCA mutation carriers exhibit a distinct CGG FMR1 repeat size pattern compared with the general population, but it is unlikely to account for the reported diminished ovarian reserve or act as a modifier breast cancer gene in BRCA mutation carriers.