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Shprintzen-Goldberg syndrome (SGS) is characterized by severe marfanoid habitus, intellectual disability, camptodactyly, typical facial dysmorphism, and craniosynostosis. Using family-based exome sequencing, we identified a dominantly inherited heterozygous in-frame deletion in exon 1 of SKI. Direct sequencing of SKI further identified one overlapping heterozygous in-frame deletion and ten heterozygous missense mutations affecting recurrent residues in 18 of the 19 individuals screened for SGS; these individuals included one family affected by somatic mosaicism. All mutations were located in a restricted area of exon 1, within the R-SMAD binding domain of SKI. No mutation was found in a cohort of 11 individuals with other marfanoid-craniosynostosis phenotypes. The interaction between SKI and Smad2/3 and Smad 4 regulates TGF-β signaling, and the pattern of anomalies in Ski-deficient mice corresponds to the clinical manifestations of SGS. These findings define SGS as a member of the family of diseases associated with the TGF-β-signaling pathway., (Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

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., (© 2011 John Wiley & Sons A/S.)

Aims: In patients with Marfan syndrome and other type-1 fibrillinopathies, genetic testing is becoming more easily available, leading to the identification of mutations early in the course of the disease. This study evaluates the cardiovascular (CV) risk associated with the discovery of a fibrillin-1 (FBN1) mutation., Methods and Results: A total of 1,013 probands with pathogenic FBN1 mutations were included, among whom 965 patients [median age: 22 years (11-34), male gender 53%] had data suitable for analysis. The percentage of patients with an ascending aortic (AA) dilatation increased steadily with increasing age and reached 96% (95% CI: 94-97%) by 60 years. The presence of aortic events (dissection or prophylactic surgery) was rare before 20 years and then increased progressively, reaching 74% (95% CI: 67-81%) by 60 years. Compared with women, men were at higher risk for AA dilatation [≤ 30 years: 57% (95% CI: 52-63) vs. 50% (95% CI: 45-55), P = 0.0076] and aortic events [≤ 30 years: 21% (95% CI: 17-26) vs. 11% (95% CI: 8-16), P < 0.0001; adjusted HR: 1.4 (1.1-1.8), P = 0.005]. The prevalence of mitral valve (MV) prolapse [≤ 60 years: 77% (95% CI: 72-82)] and MV regurgitation [≤ 60 years: 61% (95% CI: 53-69)] also increased steadily with age, but surgery limited to the MV remained rare [≤ 60 years: 13% (95% CI: 8-21)]. No difference between genders was observed (for all P> 0.20). From 1985 to 2005 the prevalence of AA dilatation remained stable (P for trend = 0.88), whereas the percentage of patients with AA dissection significantly decreased (P for trend = 0.01)., Conclusion: The CV risk remains important in patients with an FBN1 gene mutation and is present throughout life, justifying regular aortic monitoring. Aortic dilatation or dissection should always trigger suspicion of a genetic background leading to thorough examination for extra-aortic features and comprehensive pedigree investigation.

Background: TGFBR2 mutations were recognized recently among patients with a Marfan-like phenotype. The associated clinical and prognostic spectra remain unclear., Methods and Results: Clinical features and outcomes of 71 patients with a TGFBR2 mutation (TGFBR2 group) were compared with 50 age- and sex-matched unaffected family members (control subjects) and 243 patients harboring FBN1 mutations (FBN1 group). Aortic dilatation was present in a similar proportion of patients in both the TGFBR2 and FBN1 groups (78% versus 79%, respectively) but was highly variable. The incidence and average age for thoracic aortic surgery (31% versus 27% and 35+/-16 versus 39+/-13 years, respectively) and aortic dissection (14% versus 10% and 38+/-12 versus 39+/-9 years) were also similar in the 2 groups. Mitral valve involvement (myxomatous, prolapse, mitral regurgitation) was less frequent in the TGFBR2 than in the FBN1 group (all P<0.05). Aortic dilatation, dissection, or sudden death was the index event leading to genetic diagnosis in 65% of families with TGFBR2 mutations, versus 32% with FBN1 mutations (P=0.002). The rate of death was greater in TGFBR2 families before diagnosis but similar once the disease had been recognized. Most pregnancies were uneventful (without death or aortic dissection) in both TGFBR2 and FBN1 families (38 of 39 versus 213 of 217; P=1). Seven patients (10%) with a TGFBR2 mutation fulfilled international criteria for Marfan syndrome, 3 of whom presented with features specific for Loeys-Dietz syndrome., Conclusions: Clinical outcomes appear similar between treated patients with TGFBR2 mutations and individuals with FBN1 mutations. Prognosis depends on clinical disease expression and treatment rather than simply the presence of a TGFBR2 gene mutation.

The 3M syndrome is a rare autosomal recessive disorder recently ascribed to mutations in the CUL7 gene and characterized by severe pre- and postnatal growth retardation. Studying a series of 33 novel cases of 3M syndrome, we have identified deleterious CUL7 mutations in 23/33 patients, including 19 novel mutations and one paternal isodisomy of chromosome 6 encompassing a CUL7 mutation. Lack of mutations in 10/33 cases and exclusion of the CUL7 locus on chromosome 6p21.1 in six consanguineous families strongly support the genetic heterogeneity of the 3M syndrome.

TGFBR1 and TGFBR2 gene mutations have been associated with Marfan syndrome types 1 and 2, Loeys-Dietz syndrome and isolated familial thoracic aortic aneurysms or dissection. In order to investigate the molecular and clinical spectrum of TGFBR2 mutations we screened the gene in 457 probands suspected of being affected with Marfan syndrome or related disorders that had been referred to our laboratory for molecular diagnosis. We identified and report 23 mutations and 20 polymorphisms. Subsequently, we screened the TGFBR1 gene in the first 74 patients for whom no defect had been found, and identified 6 novel mutations and 12 polymorphisms. Mutation-carrying probands displayed at referral a large clinical spectrum ranging from the Loeys-Dietz syndrome and neonatal Marfan syndrome to isolated aortic aneurysm. Furthermore, a TGFBR1 gene mutation was found in a Shprintzen-Goldberg syndrome patient. Finally, we observed that the yield of mutation detection within the two genes was very low : 4.8% for classical MFS, 4.6% for incomplete MFS and 1% for TAAD in the TGFBR2 gene; 6.2%, 6.2% and 7% respectively in the TGFBR1 gene; in contrast to LDS, where the yield was exceptionally high (87.5%)., ((c) 2008 Wiley-Liss, Inc.)

Purpose: Hereditary hemorrhagic telangiectasia is an autosomal dominant disorder characterized by arteriovenous malformations (AVM), mostly cutaneous and mucous (telangiectases), but also involving the lungs (PAVM), liver (HAVM) and brain (CAVM). We studied the relationship between the phenotype and genotype in patients with a proven mutation in either ENG (HHT1) or ACVRL1 (HHT2)., Methods: Clinical features and their age of onset were compared between HHT1 and HHT2. The type of mutation was also analyzed. Clinical manifestations were distinguished from lesions found by screening., Results: Ninety-three HHT1 patients and 250 HHT2 patients were included. Epistaxis occurred later in HHT2, with incomplete penetrance (P<0.0001). Symptomatic PAVMs were more frequent in HHT1 (34.4 vs. 5.2%, P<0.001), as were cerebral abscesses (7.5 vs. 0.8%, P=0.002). Gastrointestinal bleeding occurred more frequently in HHT2 (16.4 vs. 6.5%, P=0.017). Symptomatic hepatic involvement was only seen in HHT2 patients. PAVMs were more frequently detected in asymptomatic HHT1 patients (54 vs. 12.8%, P<0.0001). PAVMs and HAVMs were often family clustered in HHT1 and HHT2, respectively. Truncating mutations were associated with a higher frequency of epistaxis and telangiectasis, in HHT2., Conclusion: This study shows major differences between HHT1 and HHT2 phenotypes, which should be taken into account for future clinical studies.

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disease characterized by arteriovenous malformations and resulting from mutations in two major genes: ENG and ACVRL1. The aim of the present study was to estimate the prevalence of the mutations of ENG and ACVRL1 in HHT, based on the largest series of patients reported so far, recruited through a national network. We previously reported the first mutation screening of both genes, in French HHT patients, using heteroduplex analysis. This previous study, bringing 60 novel mutations, provided a significant improvement to the knowledge of molecular pathology in HHT. However, 32% (n=48) of the patients with a confirmed clinical diagnosis remained without mutation. In these patients, we performed an extensive molecular analysis that included the sequencing of the whole coding sequence, the search for large rearrangements, and screening of the potential 5' regulatory regions. Additionally, due to the lack of large pedigrees suitable for linkage analysis, and since SMAD4 germline mutations have been reported in families with combined HHT and juvenile polyposis, we screened this gene and five other genes involved in the TGF-beta/BMP pathway in the patients without mutation of ENG or ACVRL1. Only a novel SMAD1 non-conservative substitution was found in one patient, changing a poorly conserved methionine to an isoleucin. Twenty-three mutations were found in ACVRL1 and 8 in ENG (including a duplication of exons 4 to 8 and deletions of exons 1 to 3 and 9 to 14). Our results, combined with our previous data, increase the mutation rate to 88% (n=119/136) in French patients with a confirmed clinical diagnosis. Our results also emphasize the higher prevalence of large insertions/deletions in ENG and the predominance of ACVRL1 over ENG mutations.

Hereditary hemmorrhagic telangiectasia (HHT, or Osler-Rendu-Weber syndrome) is an autosomal dominant disease characterized by arteriovenous malformations, affecting 1 out of 10,000 individuals in France. The disease is caused by mutations of two genes: ENG and ALK1 (ACVRL1). We screened the coding sequence of ENG and ALK1 in 160 unrelated French index cases. A germline mutation was identified in 100 individuals (62.5%). A total of 36 mutations were found in ENG, including three nonsense mutations, 19 small insertions/deletions leading to a frameshift, two inframe deletions, seven missense mutations, and five intronic or splice-site mutations. Of the 36 mutations, 33 were novel mutations. A total of 64 mutations were found in ALK1, including six nonsense mutations, 28 small insertions/deletions leading to a frameshift, one inframe deletion, 27 missense mutations, and two intronic or splice-site mutations. Of the 64 mutations, 27 were novel mutations. Mutations were found in most parts of the coding sequence for both genes, except ALK1 exon 5 and ENG exons 12 to 14. Missense mutations in ALK1 were more frequent in exons 7, 8, and 10. ENG cDNA was sequenced for three intronic mutations: c.689+2T>C produced an abnormal transcript excluding exon 5, c.1103+3&#95;1103+8del activated a cryptic splice site 22 bp upstream, and c.1428G>A produced two abnormal transcripts, one including intron 11 and the other excluding exon 10. Although most of the mutations were private, some recurrent mutations in ALK1 were of particular interest. Mutation c.1112&#95;1113dupG (p.Gly371fsX391) was found in 17 unrelated individuals sharing a common haplotype, strongly suggesting a founder effect related to the concentration of patients previously reported in a specific French region (Rhône-Alpes). Three missense mutations involved the same codon: c.1231C>T (p.Arg411Trp), c.1232G>C (p.Arg411Pro), and c.1232G>A (p.Arg411Gln) were found in seven, two, and one patients, respectively. Haplotype analysis was in favor of both a founder effect and a mutation hot-spot., (Copyright 2004 Wiley-Liss, Inc.)

The aim of this prospective study was to evaluate the consequences of the disclosure of a positive genetic test result to patients affected with cancer. Personal repercussions and patients' behavior with the transmission of their results to relatives were considered. We conducted semistructured interviews with 23 cancer patients identified as carriers of a cancer-predisposing mutation for hereditary breast ovarian or nonpolyposis colorectal cancers, 1 month after the disclosure of the test result. Eight patients spontaneously expressed distressed reactions ("you no longer feel cured"), and 14 patients reported at least one negative feeling (dissatisfied, discouraged, unhappy, or worried), despite expecting to be a carrier. Sixteen patients expressed concerns about the risk of developing another cancer, and 18 were concerned for their children's future, in that they may carry the mutation and develop a cancer. Although 8 patients found that disadvantages of knowing their genetic status outweighed the advantages, all but 1 did not regret having undergone genetic testing. All of the patients transmitted their results to at least one close relative. Although 6 of them expressed difficulties in being the only person who could transmit the information and 9 said it was a heavy responsibility, all except 1 did not want someone else to have to inform their families. Our results illustrate the potential negative impact of diagnostic genetic testing in patients with cancer. This includes distressed reactions and difficulties in transmitting their results to relatives. Future large-scale studies are warranted to confirm our findings.

Mutations in the GJB2 gene encoding connexin26 (CX26) account for up to 50% of cases of autosomal recessive hearing loss. In contrast, only one GJB2 mutation has been reported to date in an autosomal dominant form of isolated prelingual hearing loss. We report here a novel heterozygous 605G-->T mutation in GJB2 in all affected members of a large family with late childhood onset of autosomal dominant isolated hearing loss. The resulting C202F substitution, which lies in the fourth (M4) transmembrane domain of CX26, may impair connexin oligomerisation. Finally, our study suggests that GJB2 should be screened for heterozygous mutations in patients with autosomal dominant isolated hearing impairment, whatever the severity of the disease.

A gene responsible for autosomal dominant non-syndromic hearing impairment in two families (DFNA8 and DFNA12) has recently been identified as TECTA encoding alpha-tectorin, a major component of the tectorial membrane. In these families, missense mutations within the zona pellucida domain of alpha-tectorin were associated with stable severe mid-frequency hearing loss. The present study reports linkage to DFNA12 in a new family with autosomal dominant high frequency hearing loss progressing from mild to moderate severity. The candidate region refined to 3.8 cM still contained the TECTA gene. A missense mutation (C1619S) was identified in the zonadhesin-like domain. This mutation abolishes the first of the vicinal cysteines (1619Cys-Gly-Leu- 1622Cys) present in the D4 von Willebrand factor (vWf) type D repeat. These results further support the involvement of TECTA mutations in autosomal dominant hearing impairment, and suggest that vicinal cysteines are involved in tectorial membrane matrix assembly.

Hypophosphatasia is an inherited disorder characterised by defective bone mineralisation and deficiency of serum and tissue liver/bone/kidney alkaline phosphatase (L/B/K ALP) activity. We report the characterisation of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutations in a series of 13 European families affected by perinatal, infantile or childhood hypophosphatasia. Eighteen distinct mutations were found, only three of which had been reported previously in North American and Japanese populations. Most of the 15 new mutations were missense mutations, but we also found two mutations affecting donor splice sites and a nonsense mutation. A missense mutation in the last codon of the putative signal peptide probably affects the final maturation of the protein. Despite extensive sequencing of the gene and its promotor region, only one mutation was identified in two cases, one of which was compatible with a possible dominant effect of certain mutations and the putative role of polymorphisms of the TNSALP gene. In 12 of the 13 tested families, genetic diagnosis was possible by characterisation of the mutations or by use of polymorphisms as genetic markers. Hypophosphatasia diagnosis was assigned in two families where clinical, laboratory and radiographic data were unclear and prenatal diagnosis was performed in one case. The results also show that severe hypophosphatasia is due to a very large spectrum of mutations in European populations with no prevalent mutation and that genetic diagnosis of the disease must be performed by extensive analysis of the gene.