Heritable Disorders Of Connective Tissue Research Articles

Impact of heritable disorders of connective tissue on daily life of children: Parent perspectives.

The aim of this study was to investigate parent perspectives on how heritable disorders of connective tissue (HDCT) affect a child's everyday life. In addition, this study aimed to determine if parents seeking health professional services perceive their children with HDCT to have difficulties with activities reliant on hand function. This cross-sectional study used a questionnaire for parents to explore the impact of an HDCT on a child's ability to carry out everyday activities. Parents of children (8-18 years) attending a tertiary connective tissue dysplasia clinic, over a 12-month period, were invited to participate. We analysed 100 surveys completed by parents. Children with Ehlers-Danlos syndrome-hypermobile type, joint hypermobility syndrome (48%) and osteogenesis imperfecta (42%) were the largest diagnostic groups represented. Pain (73%) and fatigue (68%) were the most common symptoms parents perceived to affect day-to-day activities. More parents were satisfied with their child's self-care (61%) than school participation (33%). Keeping up with handwriting (71%) and gross motor activities (70%) were the most frequently reported difficulties at school. Most parents (65%) reported leisure activity difficulties, with pain (64%) and fatigue (60%) as the main contributing factors. This study has provided new knowledge about the concerns of parents with their child's engagement in everyday life including the impact of HDCT on hand function. Further research is needed on effective management strategies to reduce symptoms and improve hand function for these children.

A Heterozygous Missense Variant in the COL5A2 in Holstein Cattle Resembling the Classical Ehlers-Danlos Syndrome.

Simple SummaryGenodermatoses represent inherited disorders of the skin that mostly follow a monogenic mode of inheritance. Heritable connective tissue disorders such as classical Ehlers–Danlos syndrome (cEDS) belong to this group of human rare diseases that sporadically occur in other species. Herein, affected cattle are reported showing skin lesions including cutis laxa clinically and pathologically resembling cEDS in humans. Microscopic findings in the deeper dermis were consistent with collagen dysplasia. Whole-genome sequencing (WGS) identified a most likely disease-causing mutation in the COL5A2 gene. The COL5A2 gene is known to be associated with dominant inherited cEDS forms in mice and humans, but so far, it was not shown to cause a similar phenotype in domestic animals. The disease phenotype examined herein showed co-segregation with the identified missense variant within the maternal line across two generations and is most likely due to a spontaneous mutation event. Rare non-lethal disorders such as cEDS in livestock are mostly not diagnosed, but might affect animal welfare and thus lower the value of affected animals. WGS-based precision diagnostics allows understanding rare disorders and supports the value of surveillance of cattle breeding populations for harmful genetic disorders.Classical Ehlers–Danlos syndrome (cEDS) is a heritable connective tissue disorder characterized by variable degrees of skin hyperextensibility and fragility, atrophic scarring, and generalized joint hypermobility. The purpose of this study was to characterize the clinicopathological phenotype of a cEDS-affected Holstein calf and to identify the causative genetic variant associated with the disorder by whole-genome sequencing (WGS). A 3-day-old female Holstein calf was referred because of easily induced skin detachment and hyperextensibility in the neck. A complete clinical investigation was performed in the calf, dam, and maternal-grandmother. The calf and dam showed hyperextensibility of the neck skin and atrophic scarring; additionally, the calf presented skin fragility. Moreover, the histopathology of biopsies from the calf and its dam showed that the collagen bundles in affected skin areas were wavy, short, thin, and surrounded by edema and moderate to severe acute hemorrhages. Genetic analysis revealed a private heterozygous missense variant in COL5A2 (c.2366G>T; p.Gly789Val) that was present only in the calf and dam. This confirmed the diagnosis of cEDS and represents the first report of a causal variant for cEDS in cattle and the first COL5A2-related large animal model.

Clinical and genetic analysis in 185 Chinese probands of osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a well-known heritable disorder of connective tissue characterized by skeletal fragility and low bone mass. Nearly 90% of patients with OI have disease variants in COL1A1 and COL1A2 that encode for the α1 and α2 chains of type I collagen. A retrospective analysis of 185 probands who were diagnosed with OI in Shanghai Jiao Tong University Affiliated Sixth People's Hospital from March 2005 to December 2019 was performed. A total of 140 mutations in COL1A1 and 45 mutations in COL1A2 were identified, of which 18 variations were novel. In the phenotype analysis, there were more sporadic cases than familial OI cases in China (54.6% vs. 45.4%, P < 0.001). A total of 98.9% of patients presented with a fracture history. The most common fracture sites were extremity long bones (femur, tibia-fibula and radius-ulna accounted for 36.6%, 17.1% and 11.7%, respectively). Patients with OI types III and IV, especially type III, had a higher proportion of dentinogenesis imperfecta (DI) than patients with OI type I (55% vs. 28%, P < 0.001). Interestingly, G767S and D1219N in COL1A1 and G337S in COL1A2 were the most frequent (3.52%, 2.11% and 8.89%, respectively), which seem to be hotspot mutations in the COL1A1 and COL1A2 genes in Chinese patients. This study describes the mutations in the main pathogenic genes, COL1A1 and COL1A2, and the clinical characteristics of osteogenesis imperfecta in China. Furthermore, these findings help reveal the genetic basis of Asian OI patients and contribute to genetic counselling.

Urgent Endovascular Treatment of Iliac Artery Pseudoaneurysm in Patient with Ehlers-Danlos Syndrome: A Case Report

BACKGROUND: Ehlers-Danlos syndrome (EDS) type IV is a heritable disorder of connective tissue that is mainly associated with vascular maladies such as aneurysms, pseudoaneurysms, and dissections with or without spontaneous rupture. Historically, vascular complications in EDS IV have been treated conservatively whenever possible, due to the high morbidity and mortality after vascular interventions, whether open or endovascular. We present a case of a ruptured pseudoaneurysm of the right common iliac artery in a 18-year-old male, who was successfully treated by endovascular approach and later diagnosed with EDS type IV.&#x0D; CASE PRESENTATION: A 18-year-old male patient was admitted in ER with sharp pain in the right hypogastrium, hypotensive and with reduced blood parameters. Multiphasic modern computed tomography (MDCT) scan of abdomen and pelvis revealed massive ride sided pelvic and retroperitoneal hematoma. The presence of pseudoaneurysms on both common iliac arteries (CIA) was detected, with small ulcer on the right side and a focal dissection on the left side. An urgent endovascular repair of the ruptured pseudoaneurysm on the right CIA with covered stent was performed. Patient’s laboratory parameters and clinical status improved significantly within the next few days.&#x0D; CONCLUSIONS: Vascular repair in EDS-IV patients carries significant risk and should be indicated very carefully. Endovascular treatment for these patients is feasible and should be considered as an alternative to open surgery in some challenging cases as this one.

Respiratory impairment impacts QOL in osteogenesis imperfecta independent of skeletal abnormalities.

Respiratory insufficiency is the leading cause of mortality in osteogenesis imperfecta (OI), a heterogeneous group of heritable connective tissue disorders characterized by fractures, bone fragility, and scoliosis. There is little research on how respiratory health influences daily life in this population. This study explores the relationship between respiratory function and quality of life in adults with OI. One hundred fifty-seven adults with OI completed the St. George's Respiratory Questionnaire (SGRQ) and provided demographic and health information through REDCap. SGRQ scores were compared to reference scores for the general population, and comparisons were made between OI type, presence of scoliosis, stature, and other factors such as age or comorbidities. Average age was 45.87 years (range 19-81). Respondents scored worse on average (32 ± 23) than the normative data (6 ± 1). Those with type I OI scored better than those with type IV (p = 0.002) or type III (p = 0.024). Total scores correlated with age, activity level, assistive device use, and presence of pulmonary or cardiac comorbidities but did not correlate with stature or degree of scoliosis. Respiratory symptoms negatively impact both psychosocial wellbeing in the OI population and limit daily physical activity. These limitations occur irrespective of their OI type, age, stature, or scoliosis and reflect the dramatic impact of respiratory status on quality of life for people with OI. Future studies should examine the etiology of respiratory insufficiency in this population so guidelines for management can be established.

Diversity in heritable disorders of connective tissue at a single center

ABSTRACT Background Heritable disorders of connective tissue (HDCT) is a heterogeneous group of conditions caused by defects in genes responsible for extracellular matrix elements. Although next-generation sequencing (NGS) technology can be used to analyze many genes at a time, precisely diagnosing HDCT is still challenging because of the overlapping phenotypes and genotypes. Methods A 67-gene NGS targeted panel or whole-exome sequencing was employed for the diagnosis of HDCT over 4 years. Phenotypes and genotypes of patients were analyzed retrospectively. Results Mutations in 16 genes were discovered in 34 patients with the suspicion of Ehlers-Danlos syndrome (n = 7), Marfan syndrome (n = 2), osteogenesis imperfecta (n = 3), skeletal dysplasia (n = 18), and others (n = 4). Eighteen patients were found to have mutations in collagen genes, three had SERPINF1 mutations, two had TRPV4 mutations, two had FBN1 mutations, two had COMP mutations, and mutations in seven other genes were found in one patient each. The eight patients with COL1A1 mutations had a wide variation in phenotype. Patients with COL3A1 and COL5A1 mutations presented with classic EDS, those with SERPINF1 mutations presented with typical OI type VI, those with TRPV4 mutations presented with severe spinal deformity, and those with COL2A1 mutations presented with syndromic or nonsyndromic bone dysplasia or only short stature. Conclusion A wide diversity in HDCT was observed. Therefore, knowledge about the phenotype-genotype correlation in HDCT is still crucial in the diagnosis of this group of diseases, and an improvement in the screening tool will be needed.

The effectiveness of conservative interventions for the management of syndromic hypermobility: a systematic literature review

Introduction‘Syndromic hypermobility’ encompasses heritable connective tissue disorders such as hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders which are characterised by excessive joint range of motion and pain. Conservative interventions such as exercise are the cornerstone of management, yet their effectiveness is unclear.AimTo systematically appraise the effectiveness of conservative management for people with syndromic hypermobility.MethodA systematic online database search was conducted (AMED, BND, CINAHL Plus, MEDLINE, PEDro, PsychINFO and SportDiscus). Potential articles were assessed for eligibility by two researchers against the following criteria: adults and children with a hEDS/HSD diagnosis (or equivalent diagnosis using specific criteria); non-pharmacological or non-surgical interventions; outcomes related to pain, physical function, psychological well-being or quality of life. Controlled trials and cohort studies were included. Critical Appraisal Skills Programme checklists were used to assess methodological quality.ResultsEleven studies were included, comprising eight controlled trials and three cohort studies. All studies investigated interventions that had exercise as the primary component. Three small controlled studies demonstrated superior effects of conservative management relative to a control group. However, those studies only focused on a single area of the body, only recruited women, and had no long-term follow-up. All studies reported improvements in a wide range of outcomes over time.ConclusionControlled trial evidence for the superiority of conservative management over comparators is weak. There is some evidence that people improve over time. Robust randomised controlled trial research of the long-term effectiveness of ‘whole-body’ (rather than individual joints or body areas) conservative management is required.Key Points• Conservative management is the cornerstone of management of syndromic hypermobility.• The review found that evidence for the effectiveness of conservative management relative to no treatment or other conservative comparators was weak.• However, there was consistent evidence for effectiveness from pre- to post-treatment.• Further robust randomised controlled trial evidence is required.

Atlanto-axial rotary instability (Fielding type 1): characteristic clinical and radiological findings, and treatment outcomes following alignment, fusion, and stabilization

Atlanto-axial instability (AAI) is common in the connective tissue disorders, such as rheumatoid arthritis, and increasingly recognized in the heritable disorders of Stickler, Loeys-Dietz, Marfan, Morquio, and Ehlers-Danlos (EDS) syndromes, where it typically presents as a rotary subluxation due to incompetence of the alar ligament. This retrospective, IRB-approved study examines 20 subjects with Fielding type 1 rotary subluxation, characterized by anterior subluxation of the facet on one side, with a normal atlanto-dental interval. Subjects diagnosed with a heritable connective tissue disorder, and AAI had failed non-operative treatment and presented with severe headache, neck pain, and characteristic neurological findings. Subjects underwent a modified Goel-Harms posterior C1-C2 screw fixation and fusion without complication. At 15 months, two subjects underwent reoperation following a fall (one) and occipito-atlantal instability (one). Patients reported improvement in the frequency or severity of neck pain (P < 0.001), numbness in the hands and lower extremities (P = 0.001), headaches, pre-syncope, and lightheadedness (all P < 0.01), vertigo and arm weakness (both P = 0.01), and syncope, nausea, joint pain, and exercise tolerance (all P < 0.05). The diagnosis of Fielding type 1 AAI requires directed investigation with dynamic imaging. Alignment and stabilization is associated with improvement of pain, syncopal and near-syncopal episodes, sensorimotor function, and exercise tolerance.

Enhanced Notch3 signaling contributes to pulmonary emphysema in a Murine Model of Marfan syndrome

Marfan syndrome (MFS) is a heritable disorder of connective tissue, caused by mutations in the fibrillin-1 gene. Pulmonary functional abnormalities, such as emphysema and restrictive lung diseases, are frequently observed in patients with MFS. However, the pathogenesis and molecular mechanism of pulmonary involvement in MFS patients are underexplored. Notch signaling is essential for lung development and the airway epithelium regeneration and repair. Therefore, we investigated whether Notch3 signaling plays a role in pulmonary emphysema in MFS. By using a murine model of MFS, fibrillin-1 hypomorphic mgR mice, we found pulmonary emphysematous-appearing alveolar patterns in the lungs of mgR mice. The septation in terminal alveoli of lungs in mgR mice was reduced compared to wild type controls in the early lung development. These changes were associated with increased Notch3 activation. To confirm that the increased Notch3 signaling in mgR mice was responsible for structure alterations in the lungs, mice were treated with N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglucine t-butyl ester (DAPT), a gamma-secretase inhibitor, which inhibits Notch signaling. DAPT treatment reduced lung cell apoptosis and attenuated pulmonary alteration in mice with MFS. This study indicates that Notch3 signaling contributes to pulmonary emphysema in mgR mice. Our results may have the potential to lead to novel strategies to prevent and treat pulmonary manifestations in patients with MFS.

Valve-sparing versus valve-replacing aortic root operations in patients with Marfan syndrome

Aortic root dissection and rupture is the leading cause of death in patients with Marfan syndrome, a heritable connective tissue disorder that affects 1 in 10,000 individuals. Approximately 80% of those with Marfan syndrome experience annuloaortic ectasia, a distinctive form of aortic root dilation that often leads to aortic or mitral valve regurgitation, congestive heart failure, or aortic dissection or rupture. The cornerstone of care for preventing and managing such complications is replacement of the aortic root. Surgical procedures have evolved since Bentall and De Bono’s first aortic root replacement (ARR) in 1968, largely in response to late complications. Today, ARR is low-risk, systematic, and easily reproducible and has all but normalized life expectancy in Marfan syndrome. Nevertheless, long-term effects and durability remain important concerns. ARR surgical approaches include valve-replacement surgery (VRARR) with either a mechanical or tissue prosthetic aortic valve, and valve-sparing surgery (VSARR). VRARR with a mechanical valve is considered a permanent method of repair but requires lifelong anticoagulation, and the durability of bioprosthetic (tissue) valves is unclear. VSARR carries risk for adverse outcomes as well, including a higher likelihood of aortic valve regurgitation and the need for late reoperation; the method also typically involves repair of the valve leaflet, which requires advanced surgical skills and experience. The choice between VSARR and VRARR is often made intraoperatively; whether VSARR is feasible and durable is ultimately determined on the basis of the native aortic valve’s performance. For patients with leaflet fenestration, excessive tissue, annular dilation, or free margin elongation, VSARR is rarely applicable. Nonetheless, VSARR has been shown to be superior in terms of hemorrhage, thromboembolism, endocarditis, and re- exploration. Today, valve-sparing procedures are more commonly used than valve-replacement approaches in patients with Marfan syndrome.

A synonymous mutation in exon 39 of FBN1 causes exon skipping leading to Marfan syndrome

Marfan syndrome is a heritable autosomal-dominant connective tissue disorder and it was typically caused by mutations in FBN1. However, the synonymous mutation was seldom recorded to be related to Marfan syndrome. Hereon, Multiplex ligation-dependent probe amplification failed to detect a copy number variant involving FBN1 but a synonymous mutation c.4773A > G (p.Gly1591Gly) was identified by NGS in exon 39. RNA was extracted from patient's aortic tissue and reverse polymerase chain reaction demonstrated the presence of a shortened mRNA transcript. Results of minigene models indicated that c.4773A > G was bona fide responsibility for the aberrant splicing pattern, and artificial mutations of c.4773A > C and c.4773A > T also gave rise to fragments with exon 39 entire skipped. Together, the novel synonymous mutations in c.4773 position (A > G, C, T), middle of exon 39 of FBN1 gene, was found to be associated with Marfan syndrome by altering the splicing pattern of pre-mRNA.

Audit of Gastrointestinal Manifestations in Patients with Loeys–Dietz Syndrome and Vascular Ehlers–Danlos Syndrome

Loeys-Dietz syndrome (LDS) and vascular Ehlers-Danlos Syndrome (vEDS) are genetically heterogeneous heritable disorders of connective tissue. Both are multi-system disorders with dominant vascular pathology and associated gastrointestinal manifestations. To summarize the abdominal manifestations found in these two disorders in a cohort of patients seen at Mayo Clinic during a period of 25years. Data were collected via the advanced cohort explorer (ACE) of Mayo Clinic records from 1994 to 2018 in patients with vEDS or LDS confirmed by genetic testing and/or medical genetics consultation. We extracted information concerning gastrointestinal symptoms, abdominal hernias, and vascular manifestations or complications. We identified and reviewed records of 68 vEDS and 13 LDS patients. Patients were similar in age at diagnosis and gender distribution. Gastrointestinal symptoms were frequently reported in both disorders and largely similar, although altered bowel function was more prevalent in LDS patients. Hernias were present in similar proportions of patients with vEDS and LDS; however, ventral hernias were more frequent and more likely to be postoperative in vEDS than LDS. LDS patients had more arterial aneurysms overall (76.9% LDS vs. 58% vEDS, p = 0.02) and a higher proportion required arterial repair (69.2% LDS vs. 32.7% vEDS S, p = 0.03). Co-morbidities of autonomic dysfunction, psychopathology (most commonly anxiety, depression, adjustment disorder), and allergy were more prevalent in LDS than vEDS. Patients with vEDS and LDS had a propensity for gastrointestinal symptoms, abdominal hernias, and aneurysm formation, but repair for arterial rupture was more prevalent in LDS than EDS.

Marfan Syndrome: Using genetic maps to lead the way to new diagnostics and treatments

Marfan Syndrome is a heritable disorder of connective tissue caused by a mutated extracellular matrix glycoprotein protein, affecting 1 in 5,000 people worldwide. This protein is responsible for support and elasticity meaning that people affected by this disorder manifest with weakened tendons, ligaments and other connective tissues. Patients exhibit a wide variety of symptoms including, scoliosis, abnormally slender digits, vision problems and enlarged blood vessels. Marfan’s follows an autosomal dominant pattern of inheritance and has a penetrance of 100%, meaning that anyone inheriting the gene will be affected by the disease. This study focuses on the developments in the field of DNA mapping and how these advancements have improved the diagnostic tools and treatments for this disease. After exploring the methodology of DNA mapping, the LOD scores for Marfan Syndrome are discussed and compared in order to conclude which chromosome carried the mutation; it was found that chromosome 15 carries. Additionally, the results compare and contrast different genetic markers and identifies a link between markers D15529 and D15545. Although this technology is fairly recent and has thus not been studied as extensively as traditional methods, the information gathered in this research illustrates the methodology of DNA mapping and how; by understanding the gene expression and mutation at a biochemical level, diagnostics and treatments for patients can be tailored specifically to the disease and not just management of the symptoms.

Symptomatic joint hypermobility.

Joint hypermobility is relatively common and has many influences such as age, gender, training, and ethnicity among many. Joint hypermobility may be asymptomatic or symptomatic. It may also be non-syndromic or syndromic. However, "asymptomatic" joint hypermobility may result in repetitive use injury, alter biomechanics of joints at other body sites, or become symptomatic later in life. Symptomatic joint hypermobility can result from soft-tissue rheumatism (e.g. bursitis, tendonitis, etc.) or muscular tension pain due to muscular imbalance. Generalized joint hypermobility (GJH) can be easily assessed using a standardized, quick, in-office examination. Management is relatively straight forward once joint hypermobility is recognized using neuromuscular re-training. It is important to recognize that GJH may also be a feature of a heritable connective tissue disorder with other systemic findings. Therefore, assessing joint hypermobility in those with musculoskeletal complaints may lead to recognizing systemic manifestations and allow the appropriate management.

Craniofacial Morphology of Juvenile Mice with Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a heritable connective tissue disorder affecting the synthesis and structure of type I collagen (Col1) due to autosomal dominant mutations in proa1(I) or proa2(I) collagen genes (COL1A1 and COL1A2). Clinical manifestations of the severe OI type III include bone fragility, reduced physical stature, low bone mineral density, and midface hypoplasia resulting in a “triangle face” phenotype. To investigate the influence of Col1 on juvenile craniofacial morphology, we used the homozygous OI murine (OIM−/−) mouse model at the weaning stage (21 days).The OIM−/− mouse has a nonlethal recessively inherited mutation of the COL1A2 gene and exhibits adult cranial and post‐cranial phenotypes similar to humans with severe OI type III. OIM−/− and wild type (WT) littermates were weaned at 21 days and scanned in‐vivo with a Skyscan 1176 micro‐CT system. Craniofacial landmarks were collected using 3D Slicer software. Interlandmark distances (ILDs) and centroid sizes were calculated using Past 2.17 software. ILDS were scaled against skull/mandible centroid size to account for the effect of overall body size on shape analyses. Mann‐Whitney U‐tests were used to compare both absolute and relative (scaled) ILDs between the genotypes.Craniomandibular centroid sizes and absolute linear distances (skull, rostrum, palate, and mandible lengths) demonstrate that the OIM−/− mice are smaller overall than their WT littermates. When scaled to centroid size, juvenile OIM−/− mice have a decrease in nasal length, midface height, and mandibular diastema length and an increase in hemimandible length compared to WT mice. For a given skull length, OIM−/− mice have shorter faces in both the anteroposterior and dorsoventral dimensions.The morphometric changes seen in the juvenile OIM−/− mice replicate the “triangle face” that is commonly seen in human pediatric populations with OI. This suggests that this mouse model can potentially be used to investigate the structural changes underlying the human OI phenotype and potential therapeutic interventions. The results of this study can be used to inform future studies of craniofacial developmental in older OIM−/− mice.Support or Funding InformationThis research was supported by an Indiana University Collaborative Research Grant and the Ralph W. and Grace Showalter Trust.

Features of heritable disorders of connective tissue in children with acute rheumatic fever and rheumatic heart disease.

ObjectivesHeritable disorders of connective tissue (HDCT) are associated with morphological and functional disorders of different organs and systems. The aim of our study was to determine the clinical signs of heritable disorders of connective tissue and oxyproline levels in children with acute rheumatic fever (ARF) and rheumatic heart disease (RHD).Material and methodsA total of 155 patients aged 4 to 17 years participated in the study: 23 with ARF, 78 with RHD, and 54 healthy patients with a history of ARF. All patients underwent a standardized examination protocol, which consisted of a detailed medical history recorded by the physician, general and special laboratory tests, electrocardiogram, echocardiography, and Doppler echocardiography. Special attention was paid to the clinical signs of HDCT. The intensity of the metabolic processes in the connective tissue was evaluated by serum oxyproline levels.ResultsThe signs of HDCT were revealed in 121 (78.1%) of the patients with ARF and RHD. Among cardiovascular manifestations, we observed mitral valve prolapse most often – in 91 (58.7%) patients. Musculoskeletal anomalies were observed in 94 (60.7%) patients. Both groups of patients with ARF and RHD had elevated mean serum oxyproline levels.ConclusionsChildren with acute rheumatic fever and rheumatic heart disease presented with a number of signs characteristic of heritable connective tissue disorders. The cardiovascular and musculoskeletal system changes are the most frequent among all features of HDCT. Elevated levels of serum oxyproline in patients with ARF and RHD confirm connective tissue disorders. Children with manifestations of HDCT are at the risk of ARF and RHD development.

Genetic Burden Contributing to Extremely Low or High Bone Mineral Density in a Senior Male Population From the Osteoporotic Fractures in Men Study (MrOS).

ABSTRACTWorldwide, one in five men aged over 50 years will experience osteoporosis or a clinical bone fracture, with a greater fracture‐related mortality rate than women. However, the genetic etiology of osteoporosis in men is still poorly understood. We aimed to identify the genetic variants and candidate genes associated with extremely low or high BMD for a better understanding of the biology underlying low bone density that may point to potential therapeutic targets for increasing bone mass. Subjects from the Osteoporotic Fractures in Men Study (MrOS) cohort were evaluated by age and BMI‐adjusted total hip BMD. Those with BMD values 3 SDs away from the mean were selected and the remaining individuals whose adjusted BMD ranked at the highest or lowest 100 were included. Men with the lowest adjusted BMD (N = 98) and highest adjusted BMD (N = 110) were chosen for exome sequencing. Controls (N = 82) were men of Northern and Western European descent from the US Utah population of the 1000 Genomes Project. Fisher's exact test was performed to compare low‐ or high‐BMD subjects with controls for single‐gene associations. Additionally, sets of candidate genes causative of heritable disorders of connective tissue, including osteogenesis imperfecta (OI) and Ehlers‐Danlos syndrome (EDS), were grouped for multigene and mutation burden analyses. No single‐gene associations with rare variants were found for either the low BMD group (33 genes) or high BMD group (18 genes). In the group of OI genes, we detected a significant threefold increased accumulation of rare variants in low‐BMD subjects compared with controls (p = 0.009). Additionally, genes associated with EDS had a twofold increased frequency in low‐BMD subjects compared with controls (p = 0.03). These findings reveal a rare variant burden in OI and EDS disease genes at low BMD, which suggests a potential gene‐panel approach to screen for multivariant associations in larger cohorts. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

A case of Marfan syndrome with massive haemoptysis from collaterals of the lateral thoracic artery

BackgroundMarfan Syndrome (MFS) is a heritable connective tissue disorder with a high degree of clinical variability including respiratory diseases; a rare case of MFS with massive intrathoracic bleeding has been reported recently.Case presentationA 32-year-old man who had been diagnosed with MFS underwent a Bentall operation with artificial valve replacement for aortic dissection and regurgitation of an aortic valve in 2012. Warfarin was started postoperatively, and the dosage was gradually increased until 2017, when the patient was transported to our hospital due to sudden massive haemoptysis. Computed tomography (CT) with a maximum intensity projection (MIP) revealed several giant pulmonary cysts with fluid levels in the apex of the right lung with an abnormal vessel from the right subclavian artery. Transcatheter arterial embolization was performed with angiography and haemostasis was achieved, which suggested that the bleeding vessel was the lateral thoracic artery (LTA) branch. CT taken before the incident indicated thickening of the cystic wall adjacent to the thorax; therefore, it was postulated that the bleeding originated from fragile anastomoses between the LTA and pulmonary or bronchial arteries. It appears that the vessels exhibited inflammation that began postoperatively, which extended to the cysts.ConclusionWe experienced a case of MFS with massive haemoptysis from the right LTA. We have to be aware of the possibility that massive haemoptysis could be induced in MFS with inflamed pulmonary cysts.

A Multicenter Study of Intramedullary Rodding in Osteogenesis Imperfecta.

Background:Osteogenesis imperfecta (OI), a heritable connective tissue disorder with wide clinical variability, predisposes to recurrent fractures and bone deformity. Management requires a multidisciplinary approach in which intramedullary rodding plays an important role, especially for moderate and severe forms. We investigated the patterns of surgical procedures in OI in order to establish the benefits of rodding. The main hypothesis that guided this study was that rodded participants with moderate and severe OI would have lower fracture rates and better mobility.Methods:With data from the Linked Clinical Research Centers, we analyzed rodding status in 558 individuals. Mobility and fracture data in OI Types III and IV were compared between rodded and non-rodded groups. Univariate regression analyses were used to test the association of mobility outcomes with various covariates pertinent to rodding.Results:Of the individuals with OI, 42.1% had undergone rodding (10.7% of those with Type I, 66.4% with Type III, and 67.3% with Type IV). Rodding was performed more frequently and at a younger age in femora compared with tibiae. Expanding intramedullary rods were used more frequently in femora. In Type III, the rate of fractures per year was significantly lower (p ≤ 0.05) for rodded bones. In Type III, the mean scores on the Gillette Functional Assessment Questionnaire (GFAQ) and Brief Assessment of Motor Function (BAMF) were higher in the rodded group. However, Type-IV non-rodded subjects had higher mean scores in nearly all mobility outcomes. OI type, the use of expanding rods in tibiae, and anthropometric measurements were associated with mobility outcomes scores.Conclusions:Current practice in 5 orthopaedic centers with extensive experience treating OI demonstrates that most individuals with moderate and severe types of OI undergo rodding procedures. Individuals with severe OI have improved mobility outcomes and lower fracture rates compared with their non-rodded peers, which suggests that early bilateral rodding benefits OI Type III. Our analysis showed a change in practice patterns in the final years of the study in the severe forms, with earlier and more simultaneous rodding procedures performed.Level of Evidence:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A 45-year-old Italian male with p.(Gly1815Ser) FBN1 mutation causing a mild variant of Marfan syndrome: A case study

A 45-year-old Italian male was referred as suspected of having a heritable connective tissue disorders by clinical findings, including joint hyperlaxity and soft, smooth, velvety, and slightly elastic skin. Using a specific custom panel including genes involved in these disorders, next-generation sequencing (NGS) analysis led to the identification of the c. 5443G>A, p.(Gly1815Ser), (rs745680336) variant in fibrillin-1 (FBN1) gene, encoding the FBN1. Mutations in this protein are responsible for different connective tissue disorders, collectively known as type 1 fibrillinopathies, including Marfan syndrome (MFS). Multiple sequencing alignment of human FBN1 protein with various species revealed that the mutation occurred within a highly conserved region of the calcium-binding epidermal growth factor-like domain and affected the protein structure/function, suggesting its pathogenic role. NGS techniques successfully identified the molecular defect in this patient, clinically resembling as MFS, even if a clear genotype–phenotype correlation remains still challenging.