Marfan Syndrome, A Review Pals, Gerard
Journal of biomedicine and translational research (Semarang),
12/2018, Volume:
4, Issue:
2
Journal Article
Peer reviewed
Open access
Marfan syndrome is named after the French pediatrician Antoine Bernard-Jean Marfan who described in 1896 a girl with arachnodactyly and long limbs1. The patient also had congenital contractures of ...the elbows and would not fulfill the current criteria for Marfan syndrome. She probably was suffering from a condition that we now call contractural arachnodactyly, caused by mutations in the FBN2 gene.The clinical features of Marfan syndrome affect many systems of the body. The most obvious are the skeletal features, long limbs, tall stature, long thin fingers (arachnodactyly or spider fingers). The skeletal features can be scored objectively as: arm span more than 1.05 x body length; wrist sign (thumb and index finger can encircle the wrist of the other hand with at least one digit overlap) and thumb sign (when making a fist around the thumb, one digit of the thumb sticks out). The main neurological symptom is dural ectasias. The most severe symptoms are cardiovascular: mitralis valve prolapse, aortic dilatation and thoracic aortic aneurysms and dissections, which may lead to sudden death5. However, I noticed in discussions with patients that they often consider the ocular symptoms, severe myopia and lens luxation, the worst for themselves, because the latter may lead to blindness.
The effect of
mutation type on the severity of cardiovascular manifestations in patients with Marfan syndrome (MFS) has been reported with disparity results.
This study aims to determine the impact ...of the
mutation type on aortic diameters, aortic dilation rates and on cardiovascular events (ie, aortic dissection and cardiovascular mortality).
MFS patients with a pathogenic
mutation followed at two specialised units were included.
mutations were classified as being dominant negative (DN; incorporation of non-mutated and mutated fibrillin-1 in the extracellular matrix) or having haploinsufficiency (HI; only incorporation of non-mutated fibrillin-1, thus a decreased amount of fibrillin-1 protein). Aortic diameters and the aortic dilation rate at the level of the aortic root, ascending aorta, arch, descending thoracic aorta and abdominal aorta by echocardiography and clinical endpoints comprising dissection and death were compared between HI and DN patients.
Two hundred and ninety patients with MFS were included: 113 (39%) with an HI-
mutation and 177 (61%) with a DN-
. At baseline, patients with HI-
had a larger aortic root diameter than patients with DN-
(HI: 39.3±7.2 mm vs DN: 37.3±6.8 mm, p=0.022), with no differences in age or body surface area. After a mean follow-up of 4.9±2.0 years, aortic root and ascending dilation rates were increased in patients with HI-
(HI: 0.57±0.8 vs DN: 0.28±0.5 mm/year, p=0.004 and HI: 0.59±0.9 vs DN: 0.30±0.7 mm/year, p=0.032, respectively). Furthermore, patients with HI-
tended to be at increased risk for the combined endpoint of dissection and death compared with patients with DN-
(HR: 3.3, 95% CI 1.0 to 11.4, p=0.060).
Patients with an HI mutation had a more severely affected aortic phenotype, with larger aortic root diameters and a more rapid dilation rate, and tended to have an increased risk of death and dissections compared with patients with a DN mutation.
Abstract With the advance of genomic technologies, we are now able to detect genetic variations in patients with high accuracy, whole genome scale and relatively cost-effective. This offers an ...opportunity for altering medical practice fundamentally as well as insurance policy. Although clinicians, scientists, and health policy makers still have to deal how to interpret and handle the results that sometimes come with ambiguity and uncertainty, recent advances especially in the western world have integrated genetic tests and molecular genetic analysis for clinical management of patients. In this session, we will discuss and review the range of methods currently used in clinical setting as well as potential emerging methods in clinical molecular genetic diagnostics. Advantages and disadvantages of each methods will be carefully discussed especially application in regions of the world that have more limited access for molecular genetic tests including next generation sequencing. Outline of implementation challenges for molecular genetic tests both in term of health economics and clinical management will also be discussed. Keywords: molecular genetics, diagnostics, next generation sequencing
The Risk for Type B Aortic Dissection in Marfan Syndrome den Hartog, Alexander W., MD; Franken, Romy, MD; Zwinderman, Aeilko H., PhD ...
Journal of the American College of Cardiology,
01/2015, Volume:
65, Issue:
3
Journal Article
Peer reviewed
Open access
Abstract Background Aortic dissections involving the descending aorta are a major clinical problem in patients with Marfan syndrome. Objectives The purpose of this study was to identify clinical ...parameters associated with type B aortic dissection and to develop a risk model to predict type B aortic dissection in patients with Marfan syndrome. Methods Patients with the diagnosis of Marfan syndrome and magnetic resonance imaging or computed tomographic imaging of the aorta were followed for a median of 6 years for the occurrence of type B dissection or the combined end point of type B aortic dissection, distal aortic surgery, and death. A model using various clinical parameters as well as genotyping was developed to predict the risk for type B dissection in patients with Marfan syndrome. Results Between 1998 and 2013, 54 type B aortic dissections occurred in 600 patients with Marfan syndrome (mean age 36 ± 14 years, 52% male). Independent variables associated with type B aortic dissection were prior prophylactic aortic surgery (hazard ratio: 2.1; 95% confidence interval: 1.2 to 3.8; p = 0.010) and a proximal descending aorta diameter ≥27 mm (hazard ratio: 2.2; 95% confidence interval: 1.1 to 4.3; p = 0.020). In the risk model, the 10-year occurrence of type B aortic dissection in low-, moderate-, and high-risk patients was 6%, 19%, and 34%, respectively. Angiotensin II receptor blocker therapy was associated with fewer type B aortic dissections (hazard ratio: 0.3; 95% confidence interval: 0.1 to 0.9; p = 0.030). Conclusions Patients with Marfan syndrome with prior prophylactic aortic surgery are at substantial risk for type B aortic dissection, even when the descending aorta is only slightly dilated. Angiotensin II receptor blocker therapy may be protective in the prevention of type B aortic dissections.
(1) Mesenchymal stem cells (MSCs) are a valuable cell model to study the bone pathology of Osteogenesis Imperfecta (OI), a rare genetic collagen-related disorder characterized by bone fragility and ...skeletal dysplasia. We aimed to generate a novel OI induced mesenchymal stem cell (iMSC) model from induced pluripotent stem cells (iPSCs) derived from human dermal fibroblasts. For the first time, OI iMSCs generation was based on an intermediate neural crest cell (iNCC) stage. (2) Skin fibroblasts from healthy individuals and OI patients were reprogrammed into iPSCs and subsequently differentiated into iMSCs via iNCCs. (3) Successful generation of iPSCs from acquired fibroblasts was confirmed with changes in cell morphology, expression of iPSC markers
,
, and
and three germ-layer tests. Following differentiation into iNCCs, cells presented increased iNCC markers including
,
, and
and decreased iPSC markers, shown to reach the iNCC stage. Induction into iMSCs was confirmed by the presence of
,
, and
markers, low expression of the hematopoietic, and reduced expression of the iNCC markers. iMSCs were trilineage differentiation-competent, confirmed using molecular analyses and staining for cell-type-specific osteoblast, adipocyte, and chondrocyte markers. (4) In the current study, we have developed a multipotent in vitro iMSC model of OI patients and healthy controls able to differentiate into osteoblast-like cells.
Defects in motile cilia and sperm flagella cause primary ciliary dyskinesia (PCD), characterized by chronic airway disease, infertility, and left-right laterality disturbances, usually as a result of ...loss of the outer dynein arms (ODAs) that power cilia/flagella beating. Here, we identify loss-of-function mutations in CCDC114 causing PCD with laterality malformations involving complex heart defects. CCDC114 is homologous to DCC2, an ODA microtubule-docking complex component of the biflagellate alga Chlamydomonas. We show that CCDC114 localizes along the entire length of human cilia and that its deficiency causes a complete absence of ciliary ODAs, resulting in immotile cilia. Thus, CCDC114 is an essential ciliary protein required for microtubular attachment of ODAs in the axoneme. Fertility is apparently not greatly affected by CCDC114 deficiency, and qPCR shows that this may explained by low transcript expression in testis compared to ciliated respiratory epithelium. One CCDC114 mutation, c.742G>A, dating back to at least the 1400s, presents an important diagnostic and therapeutic target in the isolated Dutch Volendam population.
Primary ciliary dyskinesia (PCD) is a ciliopathy characterized by airway disease, infertility, and laterality defects, often caused by dual loss of the inner dynein arms (IDAs) and outer dynein arms ...(ODAs), which power cilia and flagella beating. Using whole-exome and candidate-gene Sanger resequencing in PCD-affected families afflicted with combined IDA and ODA defects, we found that 6/38 (16%) carried biallelic mutations in the conserved zinc-finger gene BLU (ZMYND10). ZMYND10 mutations conferred dynein-arm loss seen at the ultrastructural and immunofluorescence level and complete cilia immotility, except in hypomorphic p.Val16Gly (c.47T>G) homozygote individuals, whose cilia retained a stiff and slowed beat. In mice, Zmynd10 mRNA is restricted to regions containing motile cilia. In a Drosophila model of PCD, Zmynd10 is exclusively expressed in cells with motile cilia: chordotonal sensory neurons and sperm. In these cells, P-element-mediated gene silencing caused IDA and ODA defects, proprioception deficits, and sterility due to immotile sperm. Drosophila Zmynd10 with an equivalent c.47T>G (p.Val16Gly) missense change rescued mutant male sterility less than the wild-type did. Tagged Drosophila ZMYND10 is localized primarily to the cytoplasm, and human ZMYND10 interacts with LRRC6, another cytoplasmically localized protein altered in PCD. Using a fly model of PCD, we conclude that ZMYND10 is a cytoplasmic protein required for IDA and ODA assembly and that its variants cause ciliary dysmotility and PCD with laterality defects.
Abstract
Inherited bone disorders account for about 10% of documented Mendelian disorders and are associated with high financial burden. Their study requires osteoblasts which play a critical role in ...regulating the development and maintenance of bone tissue. However, bone tissue is not always available from patients. We developed a highly efficient platelet lysate-based approach to directly transdifferentiate skin-derived human fibroblasts to osteoblast-like cells. We extensively characterized our in vitro model by examining the expression of osteoblast-specific markers during the transdifferentiation process both at the mRNA and protein level. The transdifferentiated osteoblast-like cells showed significantly increased expression of a panel of osteogenic markers. Mineral deposition and ALP activity were also shown, confirming their osteogenic properties. RNA-seq analysis allowed the global study of changes in the transcriptome of the transdifferentiated cells. The transdifferentiated cells clustered separately from the primary fibroblasts with regard to the significantly upregulated genes indicating a distinct transcriptome profile; transdifferentiated osteoblasts also showed significant enrichment in gene expression related to skeletal development and bone mineralization. Our presented in vitro model may potentially contribute to the prospect of studying osteoblast-dependent disorders in patient-derived cells.
Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disease with a progressive course characterized by episodically local flare-ups, which often but not always leads to heterotopic bone ...formation (HO).
Recently, we showed that 18FNaF PET/CT may be the first tool to monitor progression of a posttraumatic flare-up leading to new HO, which was demonstrated in a patient with FOP who underwent a maxillofacial surgery.
This paper evaluates 18FNaF PET/CT as a marker of FOP disease activity, comparing its use with other imaging modalities known in literature. In addition, the follow-up of a spontaneous flare-up in a 19-year old patient is presented showing high muscle 18FNaF uptake in one defined part within the flare-up area after three weeks. During follow-up 18FNaF PET /CT scan revealed newly formed heterotopic bone but only in this previously active 18FNaF region. In conclusion, increased muscle 18FNaF uptake may predict future HO development in FOP patients. At present 18FNaF PET/CT appears to be a sensitive imaging modality to serve as a noninvasive marker for bone formation and to monitor disease activity during flare-ups in FOP.
•18FNaF PET/CT is the first marker of (early) HO formation in FOP.•HO may start 3 weeks after a new flare-up•18FNaF PET/CT can quantify the HO process
Since our discovery in 2013 that genetic defects in
lead to bone fragility, the mechanistic details of this process have remained obscure. It has been established that
variants cause syndromic and ...nonsyndromic osteoporosis as well as osteoarthritis. PLS3 codes for an actin-bundling protein with a broad pattern of expression. As such, it is puzzling how PLS3 specifically leads to bone-related disease presentation. Our review aims to summarize the current state of knowledge regarding the function of PLS3 in the predominant cell types in the bone tissue, the osteocytes, osteoblasts and osteoclasts. This is related to the role of PLS3 in regulating mechanotransduction, calcium regulation, vesicle trafficking, cell differentiation and mineralization as part of the complex bone pathology presented by PLS3 defects. Considering the consequences of PLS3 defects on multiple aspects of bone tissue metabolism, our review motivates the study of its mechanism in bone diseases which can potentially help in the design of suitable therapy.
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![[18F]NaF PET/CT scan as an ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/8756-3282/small "[18F]NaF PET/CT scan as an early marker of heterotopic ossification in fibrodysplasia ossificans progressiva")
