HHT is an autosomal dominant disease with an estimated prevalence of at least 1/5000 which can frequently be complicated by the presence of clinically significant arteriovenous malformations in the ...brain, lung, gastrointestinal tract and liver. HHT is under-diagnosed and families may be unaware of the available screening and treatment, leading to unnecessary stroke and life-threatening hemorrhage in children and adults.
The goal of this international HHT guidelines process was to develop evidence-informed consensus guidelines regarding the diagnosis of HHT and the prevention of HHT-related complications and treatment of symptomatic disease.
The overall guidelines process was developed using the AGREE framework, using a systematic search strategy and literature retrieval with incorporation of expert evidence in a structured consensus process where published literature was lacking. The Guidelines Working Group included experts (clinical and genetic) from eleven countries, in all aspects of HHT, guidelines methodologists, health care workers, health care administrators, HHT clinic staff, medical trainees, patient advocacy representatives and patients with HHT. The Working Group determined clinically relevant questions during the pre-conference process. The literature search was conducted using the OVID MEDLINE database, from 1966 to October 2006. The Working Group subsequently convened at the Guidelines Conference to partake in a structured consensus process using the evidence tables generated from the systematic searches.
The outcome of the conference was the generation of 33 recommendations for the diagnosis and management of HHT, with at least 80% agreement amongst the expert panel for 30 of the 33 recommendations.
The Marfan Syndrome Pyeritz, Reed E
Annual review of medicine,
01/2000, Letnik:
51, Številka:
1
Journal Article
Recenzirano
The Marfan syndrome (MFS), initially described just over 100 years ago, was
among the first conditions classified as a heritable disorder of connective
tissue. MFS lies at one end of a phenotypic ...continuum, with people in the
general population who have one or another of the features of MFS at the other
end, and those with a variety of other conditions in between. Diagnosis of MFS
and these other conditions remains based on clinical features. Mutations in
FBN1,
the gene that encodes fibrillin-1, are responsible for MFS and (in
a few patients) other disorders in the continuum. In addition to skeletal,
ocular, and cardiovascular features, patients with MFS have involvement of the
skin, integument, lungs, and muscle tissue. Over the past 30 years, evolution
of aggressive medical and surgical management of the cardiovascular problems,
especially mitral valve prolapse, aortic dilatation, and aortic dissection, has
resulted in considerable improvement in life expectancy.
Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) is a disorder of development of the vasculature characterized by telangiectases and arteriovenous malformations in specific ...locations. It is one of most common monogenic disorders, but affected individuals are frequently not diagnosed. The most common features of the disorder, nosebleeds, and telangiectases on the lips, hands, and oral mucosa are often quite subtle. Optimal management requires an understanding of the specific presentations of these vascular malformations, especially their locations and timing during life. Telangiectases in the nasal and gastrointestinal mucosa and brain arteriovenous malformations generally present with hemorrhage. However, complications of arteriovenous malformations in the lungs and liver are generally the consequence of blood shunting through these abnormal blood vessels, which lack a capillary bed and thus result in a direct artery-to-vein connection. Mutations in at least five genes are thought to result in hereditary hemorrhagic telangiectasia, but mutations in two genes (ENG and ACVRL1/ALK1) cause approximately 85% of cases. The frequency of arteriovenous malformations in particular organs and the occurrence of certain rare symptoms are dependent on the gene involved. Molecular genetic testing is used to establish the genetic subtype of hereditary hemorrhagic telangiectasia in a clinically affected individual and family, and for early diagnosis to allow for appropriate screening and preventive treatment.
Somatic mosaicism -- the presence of genetically distinct populations of somatic cells in a given organism -- is frequently masked, but it can also result in major phenotypic changes and reveal the ...expression of otherwise lethal genetic mutations. Mosaicism can be caused by DNA mutations, epigenetic alterations of DNA, chromosomal abnormalities and the spontaneous reversion of inherited mutations. In this review, we discuss the human disorders that result from somatic mosaicism, as well as the molecular genetic mechanisms by which they arise. Specifically, we emphasize the role of selection in the phenotypic manifestations of mosaicism.
Chromosomal microarray analysis (CMA) has improved the diagnostic rate of genomic disorders in pediatric populations, but can produce uncertain and unexpected findings. This article explores ...clinicians' perspectives and identifies challenges in effectively interpreting results and communicating with families about CMA. Responses to an online survey were obtained from 40 clinicians who had ordered CMA. Content included practice characteristics and perceptions, and queries about a hypothetical case involving uncertain and incidental findings. Data were analyzed using nonparametric statistical tests. Clinicians' comfort levels differed significantly for explaining uncertain, abnormal, and normal CMA results, with lowest levels for uncertain results. Despite clinical guidelines recommending informed consent, many clinicians did not consider it pertinent to discuss the potential for CMA to reveal information concerning biological parentage or predisposition to late‐onset disease, in a hypothetical case. Many non‐genetics professionals ordering CMA did not feel equipped to interpret the results for patients, and articulated needs for education and access to genetics professionals. This exploratory study highlights key challenges in the practice of genomic medicine, and identifies needs for education, disseminated practice guidelines, and access to genetics professionals, especially when dealing with uncertain or unexpected findings.
The diagnosis of Marfan syndrome (MFS) relies on defined clinical criteria (Ghent nosology), outlined by international expert opinion to facilitate accurate recognition of this genetic aneurysm ...syndrome and to improve patient management and counselling. These Ghent criteria, comprising a set of major and minor manifestations in different body systems, have proven to work well since with improving molecular techniques, confirmation of the diagnosis is possible in over 95% of patients. However, concerns with the current nosology are that some of the diagnostic criteria have not been sufficiently validated, are not applicable in children or necessitate expensive and specialised investigations. The recognition of variable clinical expression and the recently extended differential diagnosis further confound accurate diagnostic decision making. Moreover, the diagnosis of MFS--whether or not established correctly--can be stigmatising, hamper career aspirations, restrict life insurance opportunities, and cause psychosocial burden. An international expert panel has established a revised Ghent nosology, which puts more weight on the cardiovascular manifestations and in which aortic root aneurysm and ectopia lentis are the cardinal clinical features. In the absence of any family history, the presence of these two manifestations is sufficient for the unequivocal diagnosis of MFS. In absence of either of these two, the presence of a bonafide FBN1 mutation or a combination of systemic manifestations is required. For the latter a new scoring system has been designed. In this revised nosology, FBN1 testing, although not mandatory, has greater weight in the diagnostic assessment. Special considerations are given to the diagnosis of MFS in children and alternative diagnoses in adults. We anticipate that these new guidelines may delay a definitive diagnosis of MFS but will decrease the risk of premature or misdiagnosis and facilitate worldwide discussion of risk and follow-up/management guidelines.
Background/Aims: To predict the potential public health impact of personal genomics, empirical research on public perceptions of these services is needed. In this study, ‘early adopters’ of personal ...genomics were surveyed to assess their motivations, perceptions and intentions. Methods: Participants were recruited from everyone who registered to attend an enrollment event for the Coriell Personalized Medicine Collaborative, a United States-based (Camden, N.J.) research study of the utility of personalized medicine, between March 31, 2009 and April 1, 2010 (n = 369). Participants completed an Internet-based survey about their motivations, awareness of personalized medicine, perceptions of study risks and benefits, and intentions to share results with health care providers. Results: Respondents were motivated to participate for their own curiosity and to find out their disease risk to improve their health. Fewer than 10% expressed deterministic perspectives about genetic risk, but 32% had misperceptions about the research study or personal genomic testing. Most respondents perceived the study to have health-related benefits. Nearly all (92%) intended to share their results with physicians, primarily to request specific medical recommendations. Conclusion: Early adopters of personal genomics are prospectively enthusiastic about using genomic profiling information to improve their health, in close consultation with their physicians. This suggests that early users (i.e. through direct-to-consumer companies or research) may follow up with the health care system. Further research should address whether intentions to seek care match actual behaviors.
The family history has its origins in genealogy and over the past century has become embedded in clinical practice. Its importance in specialized circumstances is unquestioned but largely untested. ...Moreover, the relevance of the family history to common diseases, especially in an era of genomic markers that convey risk and the emphasis on "personalized medicine," must be given careful scrutiny. Given the time and expertise needed to obtain and interpret the family history, without a clearer sense of clinical validity and utility, its role will likely diminish. The time to perform the requisite investigations is now.
Replacement of the aortic root with a prosthetic graft and valve in patients with Marfan's syndrome may prevent premature death from rupture of an aneurysm or aortic dissection. We reviewed the ...results of this surgical procedure at 10 experienced surgical centers.
A total of 675 patients with Marfan's syndrome underwent replacement of the aortic root. Survival and morbidity-free survival curves were calculated, and risk factors were determined from a multivariable regression analysis.
The 30-day mortality rate was 1.5 percent among the 455 patients who underwent elective repair, 2.6 percent among the 117 patients who underwent urgent repair (within 7 days after a surgical consultation), and 11.7 percent among the 103 patients who underwent emergency repair (within 24 hours after a surgical consultation). Of the 675 patients, 202 (30 percent) had aortic dissection involving the ascending aorta. Forty-six percent of the 158 adult patients with aortic dissection and a documented aortic diameter had an aneurysm with a diameter of 6.5 cm or less. There were 114 late deaths (more than 30 days after surgery); dissection or rupture of the residual aorta (22 patients) and arrhythmia (21 patients) were the principal causes of late death. The risk of death was greatest within the first 60 days after surgery, then rapidly decreased to a constant level by the end of the first year.
Elective aortic-root replacement has a low operative mortality. In contrast, emergency repair, usually for acute aortic dissection, is associated with a much higher early mortality. Because nearly half the adult patients with aortic dissection had an aortic-root diameter of 6.5 cm or less at the time of operation, it may be prudent to undertake prophylactic repair of aortic aneurysms in patients with Marfan's syndrome when the diameter of the aorta is well below that size.
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