Role of TGFBR1 and TGFBR2 genetic variants in Marfan syndrome.

OBJECTIVE: Genetic variants in transforming growth factor beta (TGF-ß) receptors type 1 (TGFBR1) and type 2 (TGFBR2) genes have been associated with different hereditary connective tissue disorders sharing thoracic aortic aneurysm and dissection (TAA/D). Mutations in both TGFBR1/2 genes have been described in patients with TAA/D and Marfan syndrome (MFS), and they are associated consistently with Loeys-Dietz syndrome. The existing literature shows discordant data resulting from mutational screening of TGFBR1/2 genes in patients with MFS. The aim of the study was to investigate the role of TGFBR1/2 genetic variants in determining and/or modulating MFS clinical phenotype. METHODS: We investigated 75 unrelated patients with MFS referred to the Center for Marfan Syndrome and Related Disorders (Careggi University Hospital, Florence) who were subjected to FBN1 and TGFBR1/2 Sanger mutational screening. RESULTS: Forty-seven patients with MFS (63%) carried a pathogenetic FBN1 mutation. No pathogenetic mutations were detected in TGFBR1/2 genes. Ten common polymorphisms were identified in TGFBR2 and 6 in TGFBR1. Their association with cardiovascular manifestations was evaluated. Carriers of the A allele of rs11466512, delA allele of c.383delA or delT allele of c.1256-15del1T polymorphisms had a trend toward or significantly reduced z-scores (median [interquartile range (IQR)], 2.2 [1.13-4.77]; 2.1 [1.72-3.48]; 2.5 [1.85-3.86]) with respect to homozygous patients with wild-type MFS (median [IQR], 4.20 [2.39-7.25]; 3.9 [2.19-7.00]; 3.9 [2.14-6.93]). Carriers of the A allele of the rs2276767 polymorphism showed a trend toward increased z-score (median [IQR], 4.9 [2.14-7.16]) with respect to patients with wild-type MFS (median [IQR], 3.3 [1.75-5.45]). The protective effect of TGFBR1/2 genetic score including all the 4 variants was also evaluated. Patients with MFS with two or more protective alleles included in the score had statistically significant reduced aortic z-scores (median [IQR], 2.20 [1.48-3.37]) with respect to patients with 1 or no protective alleles (median [IQR], 4.20 [2.48-7.12]; P = .007). Patients with severe aortic manifestations (aortic z-score ≥ 2 or aortic surgery) showed a significantly lower prevalence of subjects with two or more protective alleles included in the genetic score (29.7%) than patients with no or milder cardiovascular involvement (63.6%; P = .029). The genetic score protective effect on global aortic manifestations severity (aortic z-score ≥ 2 or aortic surgery) was also observed at the logistic regression analysis adjusted for the presence of FBN1 gene mutations (odds ratio, 0.21; 95% CI, 0.05-0.84; P = .028). CONCLUSIONS: In conclusion, our data reappraise the role of TGFBR1 and TGFBR2 as major genes in patients with MFS, and suggest that TGFBR1/2 genetic variants (in particular when evaluated as a burden by score) might play a role in modulating the severity of cardiovascular manifestation in MFS.

Identification of fibrillin 1 gene mutations in patients with bicuspid aortic valve (BAV) without Marfan syndrome.

BACKGROUND: Bicuspid aortic valve (BAV) is the most frequent congenital heart disease with frequent involvement in thoracic aortic dilatation, aneurysm and dissection. Although BAV and Marfan syndrome (MFS) share some clinical features, and some MFS patients with BAV display mutations in FBN1, the gene encoding fibrillin-1, the genetic background of isolated BAV is poorly defined. METHODS: Ten consecutive BAV patients [8 men, age range 24-42 years] without MFS were clinically characterized. BAV phenotype and function, together with evaluation of aortic morphology, were comprehensively assessed by Doppler echocardiography. Direct sequencing of each FBN1 exon with flanking intron sequences was performed on eight patients. RESULTS: We detected three FBN1 mutations in two patients (aged 24 and 25 years) displaying aortic root aneurysm ≥50 mm and moderate aortic regurgitation. In particular, one patient had two mutations (p.Arg2726Trp and p.Arg636Gly) one of which has been previously associated with variable Marfanoid phenotypes. The other patient showed a pArg529Gln substitution reported to be associated with an incomplete MFS phenotype. CONCLUSIONS: The present findings enlarge the clinical spectrum of isolated BAV to include patients with BAV without MFS who have involvement of FBN1 gene. These results underscore the importance of accurate phenotyping of BAV aortopathy and of clinical characterization of BAV patients, including investigation of systemic connective tissue manifestations and genetic testing.

Atherosclerosis and Endometriosis: The Role of Diet and Oxidative Stress in a Gender-Specific Disorder.

Background: Accelerated atherosclerosis in patients with endometriosis has been hypothesised, and lifestyle improvement might control cardiovascular risk. We explored cardiometabolic markers and oxidative stress and evaluated the effects of the Mediterranean Diet (MD) in modulating these markers. Methods: In this prospective study, we included 35 women with endometriosis. At baseline (T0) and after 3 (T1) and 6 (T2) months from the start of the diet, we investigated cardiometabolic parameters, lifestyle and oxidative stress. Results: After a 3-month intervention with MD, we observed a significant reduction in total cholesterol (p = 0.01) and LDL-c (p = 0.003). We observed at T1 an increase in B12 and E vitamins, folate and zinc. After 6 months, zinc (p = 0.04) and folate (p = 0.08) increased in comparison to T0. A reduction in homocysteine from T0 to T1 (p = 0.01) was found. After 3 months, an increase in Rapid Assessment of Physical Activity tool 1 (RAPA) (p < 0.001) and RAPA 2 was observed (p = 0.009). We observed high levels of oxidative stress markers at baseline. After 6 months of MD, a significant improvement in lymphocyte Reactive Oxygen Species (ROS) (p < 0.001) and total antioxidant capacity was observed (p = 0.02). Conclusions: The improvement of lifestyle, and in particular the Mediterranean dietary intervention, allowed the improvement of the metabolic and oxidative profile and overall health-related quality of life.

Safe and Successful Surgical Outcome in Persons with Hemophilia A with and without Inhibitors Treated with Emicizumab: A Large, Single Center, Real-World Experience.

Emicizumab is a humanized recombinant bispecific antibody, bridging together activated factor IX (FIXa) and factor X (FX), thus mimicking the activity of FVIII in vivo. Emicizumab is designed for long-term prophylaxis in patients with severe hemophilia A with and without inhibitors. This approach provides constant protection, with significant reduction in bleeding rate and improved quality of life. However, protection provided by emicizumab is not absolute, and clotting factor concentrates (FVIII, rFVIIa, aPCC) may be necessary for post-traumatic bleeding or surgery, with a potential thrombotic risk or difficulty in preventing bleeding. Real world evidence is still scanty, especially for managing major surgery. In this study, 75 surgeries were managed in 28 patients (27 major procedures in 15 patients and 48 minor procedures in 20 patients. In 17 patients without inhibitors, 30 minor surgeries were carried out by using FVIII in 5, with only a bleeding event, which was successfully treated with FVIII concentrate. Six major surgeries were uneventfully performed with FVIII concentrate. Eleven PWHA and high-titer inhibitors underwent 39 surgical procedures (18 minor and 21 major surgeries). Minor surgeries were mostly performed without prophylaxis with rFVIIa, with only a single bleeding complication. All 21 major surgeries were covered with a homogeneous protocol using rFVIIa. In four instances, bleeding complications occurred, treated with rFVIIa. Of them, a single patient only failed to respond and died because of an uncontrollable bleeding from a large ruptured retroperitoneal pseudotumor. Surgery in patients with emicizumab can be safely carried out with the use of appropriate replacement therapy protocols.

Ectopic Fat Depots and Cardiometabolic Burden: A Possible Dangerous Liaison in Women Planning Assisted Reproduction.

Objective: We evaluated cardiometabolic burden in women planning assisted reproduction in order to identify subgroups at higher risk of pregnancy complications and cardiovascular disease. Materials and methods: In this cross-sectional study we investigated 60 infertile women with BMI≥25 kg/m2 referred to the Center for Assisted Reproduction. All women underwent metabolic, anthropometric parameters and ultrasound evaluation of ectopic fat depots. Results: All women had waist ≥80 cm. We found that 93.3% of women had pathological subcutaneous, 58.3% visceral and 80% para-perirenal fat; all women had fatty liver. Visceral fat and severity of steatosis were significantly related to the presence of metabolic syndrome (OR =5.7; p=0.03).A significant negative correlation between low HDL-c and para-perirenal fat (p<0.0001), a significant positive correlation with fasting plasma glucose and para-perirenal fat (p=0.001) were found. We observed a significant positive correlation between visceral fat and hs-CRP (p=0.002), HOMA-IR (p=0.04) and triglycerides (p=0.002), a significant negative correlation with HDL-c (p=0.05). Conclusion: This study by highlighting a clinically "dangerous liaison" between ectopic fat depots and metabolic/inflammatory markers, might permit to identify women with a worse metabolic phenotype and encourage lifestyle changes for improving their general and reproductive health together.

Homocysteine, vitamin B status and MTHFR polymorphisms in Italian infertile women.

OBJECTIVE: The purpose of this study was to evaluate the vitamin B status related to the homocysteine pathway and the prevalence of polymorphisms of the MTHFR gene in infertile women programming homologous or heterologous ART. STUDY DESIGN: We investigated 393 consecutive Caucasian women, referred to the Internal Medicine Clinic at the Center for Assisted Reproductive Technology, in order to be framed for their vascular risk before starting homologous or heterologous (oocyte donation) procedures. Total homocysteine, Vitamin B12, folate and vitamin B6 were measured. The women were divided into quartiles of serum concentration of folate, vitamin B12 and vitamin B6. The C677T and A1298C polymorphisms of the MTHFR gene were genotyped by an electronic microchip technology. RESULTS: Sixty-one women (15.5%) had hyperhomocysteinemia, 22.9% had reduced levels of vitamin B12, 4.1% had reduced levels of serum folate and 0.1% had a deficiency of vitamin B6. Women in the highest quartile of vitamin B12 and folates had lower homocysteine ​​levels than women in the first and second quartiles (p < 0.0001). The homozygosity for MTHFR C677T polymorphism was detected in 33.3% (131), and heterozygosity for MTHFR C677T polymorphism in 45.3% (178) of women. We observed a significant association between hyperhomocysteinemia and 677T allele, but not 1298C, of the MTHFR polymorphisms (p = 0.04). CONCLUSIONS: We found inadequate vitamin B status related to the homocysteine ​​pathway in women planning Assisted Reproductive Technology. Moreover, interesting association was found regarding hyperhomocysteinemia in women carrying T allele of the C677T MTHFR polymorphism. A specific supplementation with 5-MTHF and adequate vitamin B12 concentrations before Assisted Reproductive Technology warrant serious consideration, in particular in women carrying T allele of the C677T MTHFR polymorphism.

Impact of cardiovascular burden on coagulation pathway in apparently healthy women planning oocyte donation.

BACKGROUND: Hormonal fertility treatments are associated with increased coagulation factors inducing procoagulant milieu and possibly thrombotic risk. OBJECTIVE: To assess coagulation by ROTEM and coagulation tests in apparently healthy infertile women before oocyte donation procedure. METHODS: We enrolled 51 women (Assisted Reproductive Technology Centre, Florence). ROTEM and coagulation parameters were assessed before the start of infertility treatment. RESULTS: We divided women in 3 groups according to the number of cardiovascular risk factors: Group A (n = 10), Group B (n = 16), and Group C (n = 25). By considering ROTEM Extem test, a significantly increased of MCF, TPI, and G were observed in groups B (p = 0.005, p = 0.03, and p = 0.007) and C (p = 0.01, p = 0.05, and p = 0.005) in comparison to group A. As regards ROTEM Intem test, the TPI and G values were significantly higher in groups B and C in comparison to group A (p < 0.01). MCF by Fibtem test significantly increased in groups B and C than in group A (p = 0.004 and p = 0.002, respectively). FVIII, vWF:Ag and D-dimer values significantly increase according to the presence of≥2 risk factors. CONCLUSIONS: Data from coagulative assessment permit to sensitively identify women with potentially procoagulable state, which represents a risk factor of thromboembolic event during hormone treatment.

Fibroblast autofluorescence in connective tissue disorders: a future tool for clinical and differential diagnosis?

Marfan syndrome (MFS) is an inherited disorder of connective tissue due to mutations in FBN1 (90%) and TGFBR1 and TGFBR2 (5 to 10%) genes. Clinical and differential diagnosis is difficult because of the inter- and intrafamiliar marked heterogeneity and the variable onset age of clinical manifestations. Among the disorders, in differential diagnosis, thoracic aortic aneurysm (TAA) and Ullrich scleroatonic muscular dystrophy (UCMD) are reported. We evaluate the possibility of utilizing autofluorescence (AF) analysis as a diagnostic tool in the clinical and/or differential diagnosis of MFS and related disorders and in the investigation of the molecular mechanisms involved. Both multispectral imaging autofluorescence microscopy (MIAM) and autofluorescence microspectroscopy (AMS) have been used to characterize AF emission of fibroblasts from patients affected by inherited connective tissue disorders. Our preliminary results show significant differences in AF emission between normal and pathological fibroblasts, suggesting possible improvement in diagnostics of connective tissue disorders by AF analysis.

Thrombin potential and traditional coagulation assay: are they useful in exploring recurrent pregnancy loss risk?

: An adequate hemostatic balance is mandatory to get successful pregnancy. Obstetric complications, such as recurrent pregnancy loss (RPL), might be due to an impairment of placental perfusion possibly related to an underlying prothrombotic status. In this study, we used the global coagulation assay, calibrated automated thrombography and traditional coagulation assay to search for a possible underlying hypercoagulable status in women with history of RPL compared with uneventful pregnancy women. Thrombin generation, Fibrinogen, factor VIII (FVIII), Plasminogen Activator Inhibitor-1 (PAI-1) and von Willebrand factor levels were analyzed in 92 not pregnant unexplained RPL and 64 uneventful pregnancy women. In RPL women, significantly higher fibrinogen, FVIII and PAI-1 levels, and thrombin generation with respect to those observed in uneventful pregnancy women were found. By dividing the study population into quartiles of endogenous thrombin potential (ETP), a lower percentage of RPL women than uneventful pregnancy women in the second quartile was observed, whereas a higher percentage of RPL in comparison with uneventful pregnancy women in the third and fourth quartile was found (P = 0.009). Accordingly, the cut-off ETP of 1222.1 nmol/l was chosen; ETP above cut-off concentration was associated with more than two-fold increased risk of RPL (P = 0.008), also after adjustment for traditional risk factors (P = 0.009). We provided evidence of an underlying alteration of vascular network related to increased coagulation components, and fibrinolysis inhibitor levels in healthy women with history RPL; therefore, calibrated automated thrombography global assay and testing for FVIII and PAI-1 would be advisable in clinical practice to evaluate the hypercoagulable status in RPL women planning future pregnancy.

Is ectopia lentis in some cases a mild phenotypic expression of Marfan syndrome? Need for a long-term follow-up.

PURPOSE: Ectopia lentis (EL) and Marfan syndrome (MFS) are considered two distinct clinical entities. We performed genetic and clinical studies to investigate whether EL is actually distinct from MFS or if it is a mild phenotypic expression of it. METHODS: Seven patients with EL were followed for 5-10 years. Mutation screening analysis of the 65 exons of FBN1 was performed by polymerase chain reaction (PCR) amplification of genomic DNA, denaturing high pressure liquid chromatography analysis, and direct sequencing of heteroduplexes. RESULTS: Yearly examinations during the 10 years of follow-up allowed the detection of a late onset of dural ectasia in six out of seven patients (age range: 32-64 years versus 8-55 years in MFS previously reported). We also detected the onset of mild thoracic aortic dilatation in a sporadic case (age 45). Six out of seven index cases of EL turned out to be mild forms of Marfan syndrome with possible late cardiovascular involvement as detected in one case. Four novel missense mutations and one known splicing mutation were detected in five out of seven (71%) patients. Their localization confirmed the presence of a first hot spot within exons 1-15 and suggested the presence of a second one between exons 31-39. CONCLUSIONS: The presence of a second major criterion in six EL patients shifted the clinical diagnosis from EL to MFS. These data demonstrate that some cases, which are initially diagnosed as EL, turn out to be mild Marfan patients. A clinical cardiovascular follow-up is therefore highly recommended for all EL patients since they may develop thoracic aortic aneurysm (TAA) or dissection later in life. Also magnetic resonance imaging (MRI) for dural ectasia (DE) should be performed in a complete follow up for a MFS diagnosis.

Searching for a common mechanism for placenta-mediated pregnancy complications and cardiovascular disease: role of lipoprotein(a).

OBJECTIVE: To investigate lipoprotein(a) [Lp(a)], a well known cardiovascular risk factor, in women with history of placenta-mediated pregnancy complications (PMPC) compared with healthy uneventful-pregnancy women (HW), and the role of LPA gene functional polymorphisms in modulating both Lp(a) levels and PMPC risk. DESIGN: Retrospective observational study. SETTING: University hospital. PATIENT(S): A total of 360 women with history of PMPC (154 preeclampsia [PE], 121 stillbirth [SB], and 85 small for gestational age [SGA]) and 270 HW. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Lp(a) levels measurement and LPA +93C >T and +121G>A polymorphisms genotyping. RESULT(S): In PMPCs we observed higher Lp(a) levels than those found in HW and an association with PMPC risk, also after adjustment for age, familial history of cardiovascular disease, and traditional risk factors. By analyzing Lp(a) concentrations according to each pregnancy complication, we observed significantly higher Lp(a) levels in women with history of SB and PE, conferring 2.5-fold and 2-fold increased risks, respectively; no association with SGA was observed. Lp(a) concentrations progressively and significantly increased as LPA unfavorable allelic burden increased; unfavorable allelic burden influenced SB and PE risk. CONCLUSION(S): We evidenced, for the first time, an association between high Lp(a) concentrations and history of SB, and we confirmed the role of Lp(a) in PE risk; this well known atherothrombotic marker might represent one of the possible mechanisms shared by PMPC and cardiovascular disease.

Residual thrombin potential predicts cardiovascular death in acute coronary syndrome patients undergoing percutaneous coronary intervention.

INTRODUCTION: Thrombin generation (TG) is a central step of the coagulation system involved in hemostatic and thrombotic roles. Scarce data evaluating in the acute phase the association between TG and the risk of cardiovascular death of acute coronary syndrome (ACS) patients are available, in the era of percutaneous coronary intervention (PCI) and stenting with the use of dual antiplatelet treatment. MATERIALS AND METHODS: We investigated TG in 292 ACS patients undergoing PCI with stent implantation on dual antiplatelet treatment. Venous samples were obtained 12-24h after PCI. TG was assessed using the Calibrated Automated Thrombogram (CAT). RESULTS: At two years of follow-up, 57 out of 292 patients (19.5%) died from cardiovascular causes. Higher values of endogenous thrombin potential (ETP) [1115.9 (705-1441.3) vs 940.2 (666.0-1253.1), p=0.049], peak [176.1 (80.5-259.4) vs 107.3 (59.9-181.1), p=0.002] and velocity index [61.75 (21.03-97.88) vs 25.64 (11.95-50.90), p<0.001] were observed in relation to survival patients. At the multivariate model adjusted for the Global Registry of Acute Coronary Events risk score, the association between TG and cardiovascular death remained significant for ETP [OR (95% CI): 2.58 (1.10-6.03), p=0.029], peak [OR (95%CI): 3.27 (1.35-7.92), p=0.009] and velocity index [OR (95% CI): 3.06 (1.27-7.39), p=0.013]. This result was confirmed after adjustment for high on-treatment platelet reactivity [ETP: OR (95% CI) 2.35 (1.11-5.00), p=0.027; peak: OR (95% CI) 2.42 (1.13-5.15), p=0.022; velocity index: OR (95% CI) 2.43 (1.14-5.20), p=0.022]. CONCLUSIONS: ACS patients with a residual TG after PCI and stent implantation have a significantly higher risk of long-term cardiovascular death. These results might be useful in improving risk stratification for ACS patients and support the need of a tailored antithrombotic therapy.

Diastolic subclinical primary alterations in Marfan syndrome and Marfan-related disorders.

BACKGROUND: The extracellular matrix tissue of the myocardium importantly contributes to left ventricular (LV) performance. Inherited connective tissue disorders related to the FBN1 gene could involve cardiac interstitium resulting in functional abnormalities. HYPOTHESIS: To disclose a primary involvement of myocardium, LV function was studied in 28 patients affected by Marfan syndrome or Marfan-related disorders: 20 Marfan and 8 MASS (Mitral valve prolapse, Myopia, Aortic dilatation, Skeletal involvement, Skin striae) and in 28 healthy, age and gender-matched controls. No valvular regurgitation or any other cardiac alterations were present. METHODS: Echocardiographic study was performed to investigate LV systolic and diastolic function. RESULTS: No statistically significant differences were observed between patients and the control group in LV dimensions, systolic function parameters (ejection and shortening fraction), and some diastolic function parameters (E peak, A peak, E/A), while statistically significant differences were found between patients and the control group in LV mass (128.7 +/- 46.6 vs. 83.7 +/- 14.5 g/m2, p<0.008), in isovolumic relaxation time (102.0 +/- 24.0 vs. 80.1 +/- 11.2 ms, p<0.016), and in deceleration time of the E wave (127.5 +/- 19.3 vs. 208.6 +/- 24.5 ms, p<0.001) and the A wave (66.4 +/- 8.2 vs. 87.5 +/- 23.4 ms, p <0.008). CONCLUSIONS: These data show an unusual pattern of transmitral diastolic flow in which a decreased ventricular compliance and reduced myocardial relaxation coexist. Thus, in Marfan syndrome and in Marfan-related disorders, subclinical diastolic alterations are present independent of valvular disease and might represent an early marker of primary myocardial involvement.

[Prevalence of cardiovascular manifestations in Marfan syndrome]. / Prevalenza delle manifestazioni cardiovascolari nella sindrome di Marfan.

BACKGROUND: Marfan syndrome is an inherited connective tissue disorder with an autosomic dominant transmission. The prevalence is 1:5000-10 000 and the clinical major criteria involve the skeletal and ocular apparatus and the cardiovascular and central nervous system. The main cause of morbidity is represented by the thoracic aortic dissection/aneurysm that is responsible for 80% of the deaths. METHODS: We performed a clinical study on 227 patients enrolled at our Clinical and Research Marfan and Related Disorders Center. The aim of this study was to describe the prevalence of cardiovascular manifestation in this cohort of patients. RESULTS: Aortic dilation was present in 172 patients (75.8%), mitral valve prolapse in 179 (78.9%). Aortic insufficiency was present in 83 patients (36.6%), mitral insufficiency in 165 (72.7%). When analyzed separately, in < 10-year and > 40-year patients aortic dilation was more prevalent than mitral valve prolapse. Three patients presented with interatrial septal defect, 4 aortic bicuspid valve; 23 had a history of ventricular and supraventricular arrhythmias, and in 2 patients an implantable cardioverter device had been implanted. Fifty-seven patients were treated with beta-blockers and 28 had been operated for aortic aneurysmal dilation. CONCLUSIONS: In Marfan syndrome mitral valve prolapse and aortic dilation are the main cardiovascular manifestations, interatrial septal defect and aortic bicuspid valve had the same prevalence than in subjects without Marfan syndrome. These data refer to our first patient evaluation; further studies are needed to evaluate the progression and the natural history of cardiovascular manifestations in Marfan syndrome.

Dural ectasia and FBN1 mutation screening of 40 patients with Marfan syndrome and related disorders: role of dural ectasia for the diagnosis.

Marfan syndrome is an autosomal dominant disorder of connective tissue caused by mutations in the gene encoding fibrillin-1 (FBN1), a matrix component of microfibrils. Dural ectasia, i.e. enlargement of the neural canal mainly located in the lower lumbar and sacral region, frequently occurs in Marfan patients. The aim of our study was to investigate the role of dural ectasia in raising the diagnosis of Marfan syndrome and its association with FBN1 mutations. We studied 40 unrelated patients suspected for MFS, who underwent magnetic resonance imaging searching for dural ectasia. In all of them FBN1 gene analysis was also performed. Thirty-seven patients resulted affected by Marfan syndrome according to the '96 Ghent criteria; in 30 of them the diagnosis was confirmed when revaluated by the recently revised criteria (2010). Thirty-six patients resulted positive for dural ectasia. The degree of dural ectasia was grade 1 in 19 patients, grade 2 in 11 patients, and grade 3 in 6 patients. In 7 (24%) patients, the presence of dural ectasia allowed to reach a positive score for systemic feature criterion. Twenty-four patients carried an FBN1 mutation, that were represented by 13 missense (54%), and 11 (46%) mutations generating a premature termination codon (PTC, frameshifts and stop codons). No mutation was detected in the remaining 16 (6 patients with MFS and 10 with related disorders according to revised Ghent criteria). The prevalence of severe (grade 2 and grade 3) involvement of dura mater was higher in patients harbouring premature termination codon (PTC) mutations than those carrying missense-mutations (8/11 vs 2/13, P = 0.0111). Our data emphasizes the importance of dural ectasia screening to reach the diagnosis of Marfan syndrome especially when it is uncertain and indicates an association between PTC mutations and severe dural ectasia in Marfan patients.

May TGFBR1 act also as low penetrance allele in Marfan syndrome?

Marfan syndrome, a human disease involving cardiovascular and skeletal apparatuses and ocular and central nervous systems, is associated to mutations in FBN1 gene; heterozygous mutations in TGFBR2 and TGFBR1 genes were found associated to MFS type 2, characterized by the presence of skeletal and cardiovascular major criteria and absence of eye major criterion. We screened the TGFBR1 gene in 46 Marfan patients in whom mutations in FBN1 and TGFBR2 genes were excluded and the analysis of Ex1 was extended to additional 114 Marfan patients and 237 controls. We detected two potentially pathological sequence variants: the TGFBR1 6Ala allele whose frequency was higher in the group of Marfan patients (0.13) than in the controls (0.08) (p=0.013; OR=1.69) and an insertion of 20 nucleotides in the 5'UTR that turned out to be a familial silent rare polymorphism. We hypothesize that TGFBR1 sequence variants may act not only as major, but also as low penetrance alleles of the clinical phenotype in Marfan syndrome.

Vascular and connective tissue features in 5 Italian patients with homocystinuria.

Homocystinuria is a metabolic disorder associated with defects in genes encoding for methionine metabolism enzymes. Vascular and connective tissue manifestations such as deep venous thrombosis, ectopia lentis and skeletal alterations are the major clinical features. We investigated the clinical manifestations of 5 Italian homocystinuric patients, performed mutation screening analysis on cystationine beta-synthase (CBS) gene and searched for genotype/phenotype correlations. We detected mild cardiovascular and skin connective tissue stigmas in these patients, never reported in homocystinuric patients before. We found 1 novel and 7 known mutations. Our patients carried no other mutation associated with venous thrombosis. Our data stress the importance of extending the clinical investigation for connective tissue manifestations in homocystinuric patients to all the organs/systems involved in Marfan syndrome, also suggesting long term follow-ups for cardiovascular manifestations.

AGT and ACE genes influence classic mitral valve prolapse predisposition in Marfan patients.

BACKGROUND: In Marfan syndrome, the mitral valve prolapse, ranging from nonclassic to classic form on the basis of the leaflet thickness, is a common condition characterized by a highly variable structural abnormality. We investigated the role of angiotensinogen (AGT) M235T, angiotensin converting enzyme (ACE) I/D and angiotensin II type 1 receptor (AT1R) A1166C polymorphisms in influencing the susceptibility to classic or non-classic mitral valve prolapse in Marfan patients. METHODS: We studied 135 Marfan patients with mitral valve prolapse, diagnosed by echocardiography. AGT, ACE, and AT1R polymorphisms were identified by polymerase chain reaction-based restriction analysis. RESULTS: The frequency of the ACE D, but not AGT 235T and AT1R 1166C allele, was significantly higher in patients with classic mitral valve prolapse in comparison to that observed in the non-classic one (p=0.03). The percentage of subjects with the contemporaneous presence of ACE D and AGT 235T alleles was significantly higher in the classic mitral valve prolapse group in comparison to the non-classic one (79% vs. 55%, respectively; p=0.008). The concomitant presence of these two alleles was associated with increased susceptibility to the classic mitral valve prolapse (OR 3.02, p=0.016). CONCLUSIONS: Our findings show a possible role of ACE and AGT genes as predisposing factors to classic mitral valve prolapse in Marfan patients, thus suggesting a role of renin angiotensin system genes in modulating mitral valve abnormality, and the need for an interventional study with angiotensin II type 1 receptor antagonists, which considers the leaflet thickness progression in Marfan patients with MVP.