Primary lymphoedema describes a chronic, frequently progressive, failure of lymphatic drainage. We ascertained a multigenerational family in which eight individuals developed post natal lymphoedema of all four limbs. Linkage analysis revealed cosegregation of a 16.1Mb haplotype on chromosome 1q42 that contained 173 known or predicted genes. We undertook whole exome sequencing in a single affected individual and focused the search for the causative variant to within the linkage interval. This approach revealed two novel nonsynonymous single nucleotide substitutions within the chromosome 1 locus, in NVL and GJC2. We sequenced NVL and GJC2 in an additional cohort of individuals with a similar phenotype and found nonsynonymous variants in GJC2 in four additional families. This report demonstrates the power of exome sequencing efficiently applied to a traditional positional cloning pipeline in disease gene discovery.

Objective Marfan syndrome (MS) is a multisystem disorder caused by a mutation in FBN1 gene. It shares some phenotypic features with hypermobile Ehlers-Danlos syndrome (EDS) such as joint hypermobility. EDS is a group of inherited heterogenous multisystem disorders characterized by skin hyperextensibility, atrophic scarring, joint hypermobility, and generalized tissue fragility. Hypermobile EDS (hEDS) is thought to be the most common type. Recent studies have suggested an association between connective tissue hypermobility and functional gastrointestinal disorders (FGDs). The aim of this study is to determine the prevalence of gastrointestinal symptoms in patients with Marfan syndrome and hypermobile EDS. Method Patients with a diagnosis of either MS or hEDS attending cardiology or rheumatology outpatients at our hospital were asked to complete SF36 RAND and Rome IV Diagnostic questionnaires. Questionnaires were also completed by patients who are members of Marfan Association UK. The same questionnaires were also completed by age- and gender-matched controls attending fracture clinic without existing diagnoses of MS or hEDS. Results Data were collected from 45 MS patients (12 males and 33 females, age range 19–41 years, mean 28 years) and 45 hEDS patients (6 males and 39 females, age range 18–32 years, mean 24 years). None had a previous organic gastrointestinal diagnosis. The control group was matched for age and sex (18 males and 72 females, age range 18–45, mean 29 years). Both MS and hEDS groups showed a higher prevalence of abdominal symptoms compared to the control group; however, the hEDS group not only showed a higher prevalence but more frequent and severe symptoms meeting Rome IV criteria for diagnosis of FGIDs. Nearly half of the hEDS patients met the criteria for more than one FGID. The hEDS group also scored lower on quality of life (QOL) scores in comparison to either of the other groups with a mean score of 48.6 as compared to 54.2 in the Marfan group and 78.6 in the control group. Conclusion FGIDs are reported in both Marfan syndrome and hypermobile Ehlers-Danlos syndrome but appear to be more common and severe in hEDS. These patients score lower on quality of life scores as well despite hypermobility being a common feature of both conditions. Further work is needed to understand the impact of connective tissue disorders on gastrointestinal symptoms.

The diagnosis of Marfan syndrome (MFS) is challenging and international criteria have been proposed. The 1996 Ghent criteria were adopted worldwide, but new diagnostic criteria for MFS were released in 2010, giving more weight to aortic root aneurysm and ectopia lentis. We aimed to compare the diagnosis reached by applying this new nosology vs the Ghent nosology in a well-known series of 1009 probands defined by the presence of an FBN1 mutation. A total of 842 patients could be classified as MFS according to the new nosology (83%) as compared to 894 (89%) according to the 1996 Ghent criteria. The remaining 17% would be classified as ectopia lentis syndrome (ELS), mitral valve prolapse syndrome or mitral valve, aorta, skeleton and skin (MASS) syndrome, or potential MFS in patients aged less than 20 years. Taking into account the median age at last follow-up (29 years), the possibility has to be considered that these patients would go on to develop classic MFS with time. Although the number of patients for a given diagnosis differed only slightly, the new nosology led to a different diagnosis in 15% of cases. Indeed, 10% of MFS patients were reclassified as ELS or MASS in the absence of aortic dilatation; conversely, 5% were reclassified as MFS in the presence of aortic dilatation. The nosology is easier to apply because the systemic score is helpful to reach the diagnosis of MFS only in a minority of patients. Diagnostic criteria should be a flexible and dynamic tool so that reclassification of patients with alternative diagnosis is possible, requiring regular clinical and aortic follow-up.

Mutations in the FBN1 gene cause Marfan syndrome (MFS) and have been associated with a wide range of milder overlapping phenotypes. A proportion of patients carrying a FBN1 mutation does not meet diagnostic criteria for MFS, and are diagnosed with "other type I fibrillinopathy." In order to better describe this entity, we analyzed a subgroup of 146 out of 689 adult propositi with incomplete "clinical" international criteria (Ghent nosology) from a large collaborative international study including 1,009 propositi with a pathogenic FBN1 mutation. We focused on patients with only one major clinical criterion, [including isolated ectopia lentis (EL; 12 patients), isolated ascending aortic dilatation (17 patients), and isolated major skeletal manifestations (1 patient)] or with no major criterion but only minor criteria in 1 or more organ systems (16 patients). At least one component of the Ghent nosology, insufficient alone to make a minor criterion, was found in the majority of patients with isolated ascending aortic dilatation and isolated EL. In patients with isolated EL, missense mutations involving a cysteine were predominant, mutations in exons 24-32 were underrepresented, and no mutations leading to a premature truncation were found. Studies of recurrent mutations and affected family members of propositi with only one major clinical criterion argue for a clinical continuum between such phenotypes and classical MFS. Using strict definitions, we conclude that patients with FBN1 mutation and only one major clinical criterion or with only minor clinical criteria of one or more organ system do exist but represent only 5% of the adult cohort.

Background: The diagnosis of Marfan syndrome (MFS) is usually initially based on clinical criteria according to the number of major and minor systems affected following international nosology. The number of FBN1 mutation carriers, at risk of aortic complications who would not be properly diagnosed based only on clinical grounds, is of growing importance owing to the increased availability of molecular screening. The aim of the study was to identify patients who should be considered for FBN1 mutation screening. Methods: Our international series included 1009 probands with a known FBN1 mutation. Patients were classified as either fulfilling or not fulfilling “clinical” criteria. In patients with unfulfilled “clinical” criteria, we evaluated the percentage of additional patients who became positive for international criteria when the FBN1 mutation was considered. The aortic risk was evaluated and compared in patients fulfilling or not fulfilling the “clinical” international criteria. Results: Diagnosis of MFS was possible on clinical grounds in 79% of the adults, whereas 90% fulfilled the international criteria when including the FBN1 mutation. Corresponding figures for children were 56% and 85%, respectively. Aortic dilatation occurred later in adults with unfulfilled “clinical criteria” when compared to the Marfan syndrome group (44% vs 73% at 40 years, p<0.001), but the lifelong risk for ascending aortic dissection or surgery was not significantly different in both groups. Conclusions: Because of its implications for aortic follow-up, FBN1 molecular analysis is recommended in newly suspected MFS when two systems are involved with at least one major system affected. This is of utmost importance in patients without aortic dilatation and in children.

Mutations in the FBN1 gene cause Marfan syndrome (MFS) and a wide range of overlapping phenotypes. The severe end of the spectrum is represented by neonatal MFS, the vast majority of probands carrying a mutation within exons 24-32. We previously showed that a mutation in exons 24-32 is predictive of a severe cardiovascular phenotype even in non-neonatal cases, and that mutations leading to premature truncation codons are under-represented in this region. To describe patients carrying a mutation in this so-called 'neonatal' region, we studied the clinical and molecular characteristics of 198 probands with a mutation in exons 24-32 from a series of 1013 probands with a FBN1 mutation (20%). When comparing patients with mutations leading to a premature termination codon (PTC) within exons 24-32 to patients with an in-frame mutation within the same region, a significantly higher probability of developing ectopia lentis and mitral insufficiency were found in the second group. Patients with a PTC within exons 24-32 rarely displayed a neonatal or severe MFS presentation. We also found a higher probability of neonatal presentations associated with exon 25 mutations, as well as a higher probability of cardiovascular manifestations. A high phenotypic heterogeneity could be described for recurrent mutations, ranging from neonatal to classical MFS phenotype. In conclusion, even if the exons 24-32 location appears as a major cause of the severity of the phenotype in patients with a mutation in this region, other factors such as the type of mutation or modifier genes might also be relevant.

Aims: Marfan syndrome (MFS) is a dominantly inherited connective tissue disorder caused by mutations in the fibrillin-1 gene. Past research has focused on younger patients as lifespan was known to be significantly reduced. This study aims to describe the complications, including those affecting the eyes, heart and musculoskeletal system, faced by older survivors. Methods: All 2500 patient records from the National Marfan Syndrome Clinical Database were searched for suitable participants aged 50 or older. One hundred and fifty-six questionnaires were posted to patients with MFS. These patients were sent a detailed questionnaire regarding medical aspects of their disease. Those included in the study were sent questionnaires for spouses and friends (not blood relatives) to complete, to provide control data. Other age- and sex-matched controls were recruited locally. Results: Sixty questionnaires from patients with MFS (35%) were returned and eligible for inclusion in the study, comprising 28 female patients and 32 male patients with a median age of 57. We recruited 56 eligible controls. Our results revealed that patients over 50 years of age with MFS may be at a higher risk than previously assumed for retinal detachment (reported by 24% of our respondents) and cardiovascular abnormalities (42% have had past aortic surgery; 53% report palpitation). Lesser known complications were also reported, including cataract (reported by 27%). Conclusions: Medical practitioners should be aware of the range of complications that can occur in patients with MFS in addition to the normal ageing process. Health problems in MFS patients over 50 may require investigation and specific therapy earlier than in the normal ageing population, because of the degenerative nature of this genetic condition.

Mutations in the fibrillin-1 (FBN1) gene cause Marfan syndrome (MFS) and have been associated with a wide range of overlapping phenotypes. Clinical care is complicated by variable age at onset and the wide range of severity of aortic features. The factors that modulate phenotypical severity, both among and within families, remain to be determined. The availability of international FBN1 mutation Universal Mutation Database (UMD-FBN1) has allowed us to perform the largest collaborative study ever reported, to investigate the correlation between the FBN1 genotype and the nature and severity of the clinical phenotype. A range of qualitative and quantitative clinical parameters (skeletal, cardiovascular, ophthalmologic, skin, pulmonary, and dural) was compared for different classes of mutation (types and locations) in 1,013 probands with a pathogenic FBN1 mutation. A higher probability of ectopia lentis was found for patients with a missense mutation substituting or producing a cysteine, when compared with other missense mutations. Patients with an FBN1 premature termination codon had a more severe skeletal and skin phenotype than did patients with an inframe mutation. Mutations in exons 24-32 were associated with a more severe and complete phenotype, including younger age at diagnosis of type I fibrillinopathy and higher probability of developing ectopia lentis, ascending aortic dilatation, aortic surgery, mitral valve abnormalities, scoliosis, and shorter survival; the majority of these results were replicated even when cases of neonatal MFS were excluded. These correlations, found between different mutation types and clinical manifestations, might be explained by different underlying genetic mechanisms (dominant negative versus haploinsufficiency) and by consideration of the two main physiological functions of fibrillin-1 (structural versus mediator of TGF beta signalling). Exon 24-32 mutations define a high-risk group for cardiac manifestations associated with severe prognosis at all ages.

Glaucoma is a leading cause of blindness in virtually every country. Development of an accurate diagnostic test for presymptomatic detection of individuals at risk is an urgent requisition for this condition. Herein, we report mapping of a new adult-onset primary open-angle glaucoma (POAG) locus on 5q22.1 (GLC1G) and identification of its defective gene. Mutation screening of seven candidate genes from the GLC1G critical region (approximately 2 Mb between D5S1466 and D5S2051) identified only one significant alteration in the WDR36 (WD40-repeat 36) gene. This mutation (i.e. D658G) was segregated in all affected members of our first GLC1G-linked family but it was absent in 476 normal control chromosomes. Further screening of WDR36 in a total of 130 POAG families revealed 24 DNA variations. Overall, four mutations (N355S, A449T, R529Q and D658G) were identified in 17 (5.02-6.92%) unrelated POAG subjects, 11 with high-pressure and six with low-pressure glaucoma. These mutations were absent in a minimum of 200 normal control chromosomes and, further they were conserved between WDR36 orthologues in mouse, rat, dog, chimp and human. WDR36 is a novel gene with 23 exons, which encodes for 951 amino acids and a protein with multiple G-beta WD40 repeats. By northern blotting, two distinct mRNA transcripts of 5.9 and 2.5 kb were observed in human heart, placenta, liver, skeletal muscle, kidney and pancreas. WDR36 gene expression in lens, iris, sclera, ciliary muscles, ciliary body, trabecular meshwork, retina and optic nerve were established by RT-PCR. In mouse, two transcripts of 3.5 and 2.9 kb showed analogous expression patterns to human. mRNA expressions were detected in 7-, 11-, 15- and 17-day-old developing mouse embryos. In summary, WDR36 is a novel causative gene for adult-onset POAG at the GLC1G locus. Specific ocular expressions and observed mutations are consistent with WDR36 role in etiology of both high- and low-pressure glaucoma.