A new type of Ehlers-Danlos syndrome associated with tortuous systemic arteries in a large kindred from Qatar

Clinical and Radiographic Predictors of Successful Coronary Angiography Through Right Radial Artery Access

Background: One of the limitations of the right radial access approach is complex vessel anatomy, such as subclavian tortuosity. Several clinical predictors have been proposed for tortuosities, such as older age, female sex and hypertension. In this study, we hypothesised that chest radiography would add predictive value to the traditional predictors. Methods: This prospective blinded study included patients who underwent transradial access coronary angiography. They were classified into four groups according to difficulty: Group I, Group II, Group III and Group IV. Different groups were compared according to clinical and radiographic characteristics. Results: The study included 108 patients (54, 27, 17 and 10 patients in Groups I, II, III and IV, respectively). The rate of crossover to transfemoral access was 9.26%. Age, hypertension and female sex were associated with a greater difficulty and failure rates. Regarding radiographic parameters, a higher failure rate was associated with a higher diameter of the aortic knuckle (Group IV, 4.09 ± 1.32 cm versus Groups I, II and III combined, 3.26 ± 0.98 cm; p=0.015) and the width of the mediastinum (Group IV, 8.96 ± 2.88 cm versus Groups I, II and III combined, 7.28 ± 1.78 cm; p=0.009). The cut-off value for prominent aortic knuckle was 3.55 cm (sensitivity 70% and specificity 67.35%) and the width of mediastinum was 6.59 cm (sensitivity 90% and specificity 42.86%). Conclusion: Radiographic prominent aortic knuckle and wide mediastinum are valuable clinical parameters and useful predictors for transradial access failure caused by tortuosity of the right subclavian/brachiocephalic arteries or aorta.

Ultrastructure abnormalities of collagen and elastin in Arab patients with arterial tortuosity syndrome

Arterial tortuosity syndrome (ATS) is a rare autosomal recessive disease characterized by elongation and tortuosity of the large and medium sized arteries. ATS patients display features that are also found in Ehlers-Danlos syndromes (EDS) patients. ATS is caused by pathogenic mutations in the SLC2A10 gene, which encodes for the glucose transporter, GLUT10. The study aimed at examining the ultrastructure of skin for abnormalities that can explain the loose skin and arterial phenotypes of Arab patients with the p.S81R mutation in SLC2A10. Forty eight patients with SLC2A10 mutation were recruited for this study. Skin biopsy specimens from 3 children with ATS and a healthy child were examined by electron microscopy to determine the ultrastructure of collagen and elastin. Histopathologic staining of sections from tissue biopsy specimens were also performed. In the skin from ATS patients, large spaces are discovered among collagen fibrils suggesting disorganization of the collagen structures. Furthermore, elastin fiber contents and their thickness are reduced in the skin. In small muscular arteries in the skin from ATS patients, discontinued internal elastic lamina, lack of myofilaments, and disorganized medial smooth muscle cells with vacuolated cytoplasm are present. The disorganization of collagen fibrils and reduced elastin contents in the skin may explain the loose skin phenotype of ATS patients similar to the EDS patients. The lack of elastin in small muscular arteries may have contributed to the development of arterial tortuosity in these patients. This article is protected by copyright. All rights reserved.

Clinical genetics and genomic medicine in Qatar

Clinical genetics and genomic medicine in Qatar.

Mitral Prolapse: An Old Mysterious Entity - The Incremental Role of Multimodality Imaging in Sports Eligibility

Mitral valve prolapse is generally a benign condition characterized by fibromyxomatous changes of the mitral leaflet with displacement into the left atrium and late-systolic regurgitation. Although it is an old clinical entity, it still arouses perplexity in diagnosis and clinical management. Complications, such as mitral regurgitation (MR), atrial fibrillation, congestive heart failure, endocarditis, ventricular arrhythmias, and sudden cardiac death (SCD), have been reported. A large proportion of the overall causes of SCD in young competitive athletes is explained by mitral valve prolapse. Recent studies have shown the fibrosis of the papillary muscles and inferobasal left ventricular wall in mitral valve prolapse, suggesting a possible origin of ventricular fatal arrhythmias. Athletes with mitral valve prolapse and MR should undergo annual evaluations including physical examination, echocardiogram, and exercise stress testing to evaluate the cardiovascular risks of competitive sports and obtain the eligibility. In this setting, multimodality imaging techniques – echocardiography, cardiac magnetic resonance, and cardiac computed tomography – should provide a broad spectrum of information, from diagnosis to clinical management of the major clinical profiles of the disease.

Ascending Aortic Aneurysm in a Case of Arterial Tortuosity Syndrome: A Rare Tortuous Disorder

Aortic aneurysms are a common entity among adults but very rare in the pediatric age-group. Association with autosomal inheritance is well established. We describe the unusual clinical presentation of a large ascending aortic aneurysm in a young child who was ultimately found to have severe diffuse arterial tortuosity.

Arterial Tortuosity Syndrome: An Approach through Imaging Perspective

This pictorial illustration demonstrates various aspects of arterial tortuosity syndrome (ATS) obtained predominantly from a multiple detector computed tomography (MDCT) examination of a patient. In addition, a comprehensive review of typical multi-modality imaging observations in patients with ATS is presented along with a description of a few imaging signs. Non-invasively obtained, conclusive information is required in patients with ATS in view of the fragile vascular structures involved. An amazing wealth of information can be obtained by reviewing the volumetric data sets of MDCT examination. In the context of incomplete clinical information or remote reading of radiographic examination with inadequate clinical details, ability to “image data mine” the hidden, unexplored information may be vastly useful. The role of MDCT as a single modality of evaluation in ATS is highlighted.

Characterization of a distinct lethal arteriopathy syndrome in twenty-two infants associated with an identical, novel mutation in FBLN4 gene, confirms fibulin-4 as a critical determinant of human vascular elastogenesis

BACKGROUND

Vascular elasticity is crucial for maintaining hemodynamics. Molecular mechanisms involved in human elastogenesis are incompletely understood. We describe a syndrome of lethal arteriopathy associated with a novel, identical mutation in the fibulin 4 gene (FBLN4) in a unique cohort of infants from South India.

METHODS

Clinical characteristics, cardiovascular findings, outcomes and molecular genetics of twenty-two infants from a distinct population subgroup, presenting with characteristic arterial dilatation and tortuosity during the period August 2004 to June 2011 were studied.

RESULTS

Patients (11 males, 11 females) presented at median age of 1.5 months, belonging to unrelated families from identical ethno-geographical background; eight had a history of consanguinity. Cardiovascular features included aneurysmal dilatation, elongation, tortuosity and narrowing of the aorta, pulmonary artery and their branches. The phenotype included a variable combination of cutis laxa (52%), long philtrum-thin vermillion (90%), micrognathia (43%), hypertelorism (57%), prominent eyes (43%), sagging cheeks (43%), long slender digits (48%), and visible arterial pulsations (38%). Genetic studies revealed an identical c.608A > C (p. Asp203Ala) mutation in exon 7 of the FBLN4 gene in all 22 patients, homozygous in 21, and compound heterozygous in one patient with a p. Arg227Cys mutation in the same conserved cbEGF sequence. Homozygosity was lethal (17/21 died, median age 4 months). Isthmic hypoplasia (n = 9) correlated with early death (≤4 months).

CONCLUSIONS

A lethal, genetic disorder characterized by severe deformation of elastic arteries, was linked to novel mutations in the FBLN4 gene. While describing a hitherto unreported syndrome in this population subgroup, this study emphasizes the critical role of fibulin-4 in human elastogenesis.

Arterial tortuosity syndrome: A rare entity

We present a 5 month old baby who was referred for an incidental detection of a murmur and was found to have tortuous pulmonary arteries with multiple peripheral pulmonary stenoses and bilateral inguinal hernia pointing towards the diagnosis of arterial tortuosity syndrome.

Ehlers-Danlos syndrome and neurological features: a review

Ehlers-Danlos Syndrome is a term that comprises a variety of inherited connective tissue disorders characterized primarily by skin hyperextensibility, joints hypermobility and excessive dislocations, easy bruisability, generalized fragility. If much is known about orthopedic or physiatric features of this syndrome, poor is known about the neurological ones. Thus neurological assessment is very important due to the possible various clinical manifestations in this syndrome.

A novel non-sense mutation in the SLC2A10 gene of an arterial tortuosity syndrome patient of Kurdish origin

Arterial tortuosity syndrome (ATS) is a rare autosomal recessive disorder in which patients display tortuosity of arteries in addition to hyperextensible skin, joint laxity, and other connective tissue features. This syndrome is caused by mutations in the SLC2A10 gene. In this article we describe an ATS girl of Kurdish origin who, in addition to arterial tortuosity and connective tissue features, displays stomach displacement within the thorax and bilateral hip dislocation. Clinical details of this patient have been reported previously. Sequencing of the SLC2A10 gene identified a novel homozygous non-sense c.756C>A mutation in this patient's DNA. This mutation in the SLC2A10 gene replaces a cysteine encoding codon with a stop signal. This is believed to cause a premature truncation of GLUT10 protein in this patient. We conclude that patients of Kurdish origin who display arterial tortuosity associated with skin hyperextensibility, joint hypermobility, and characteristic facial features may carry mutations in the SLC2A10 gene.

Single gene disorders associated with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth defect with a high pre- and postnatal mortality. Although the majority of diaphragmatic hernias occur as isolated malformations, additional major and minor anomalies are common and are present in more than 40% of patients. There are compelling data for the importance of genetic factors in the etiology of CDH, but the pathogenesis and the causative genes for CDH in humans remain elusive. There are more than 70 syndromes in which diaphragmatic hernias have been described, and several of these syndromes are single gene disorders for which the gene is known. One method for identifying the causative genes in isolated CDH is to study syndromes with known genes in which CDH is a recognized feature, with the rationale that those genes have a role in diaphragm development. This review discusses the syndromes that are most commonly associated with CDH, with greater attention towards syndromes in which the causative genes have been identified, including Simpson-Golabi-Behmel syndrome, Denys-Drash syndrome, spondylocostal dysostosis, craniofrontonasal syndrome, Cornelia de Lange syndrome and Marfan syndrome.

Molecular genetics of congenital diaphragmatic defects

Congenital diaphragmatic hernia (CDH) is a severe birth defect that is accompanied by malformations of the lung, heart, testis, and other organs. Patients with CDH may have any combination of these extradiaphragmatic defects, suggesting that CDH is often a manifestation of a global embryopathy. This review highlights recent advances in human and mouse genetics that have led to the identification of genes involved in CDH. These include genes for transcription factors, molecules involved in cell migration, and extracellular matrix components. The expression patterns of these genes in the developing embryo suggest that mesenchymal cell function is compromised in the diaphragm and other affected organs in patients with CDH. We discuss potential mechanisms underlying the seemingly random combination of diaphragmatic, pulmonary, cardiovascular, and gonadal defects in these patients.

Recurrent congenital diaphragmatic hernia in Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) includes a group of connective tissue disorders with abnormal collagen metabolism and a diverse clinical spectrum. We report two siblings with EDS who both presented with congenital diaphragmatic hernia (CDH). The elder sister suffered from recurrent diaphragmatic hernia twice and EDS was overlooked initially. Echocardiography as well as contrast-enhanced magnetic resonance angiography (MRA) showed dilatation of the pulmonary artery, and marked elongation and tortuosity of the aorta and its branches. A diagnosis of EDS was eventually established when these findings were coupled with the clinical features of hyperelastic skin. Her younger brother also had similar features. This report emphasizes that EDS may present as CDH in a small child which could easily be overlooked. Without appropriate surgery, diaphragmatic hernia might occur. Echocardiographic screening is recommended in patients with CDH. Contrast-enhanced MRA can be helpful in delineation of abnormally tortuous aortic great vessels that are an important clue to the early diagnosis of EDS.

The genetics of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth defect with a high mortality and morbidity. A clear understanding of the pathogenesis of CDH is critical for determining prognosis and planning treatment, but to date, information on the genetic etiology of both nonsyndromic and syndromic CDH is limited. This paper summarizes the current knowledge concerning the genes, syndromes, and chromosome aberrations associated with CDH in humans and in animal model systems. Mutations in several different genes have been described in syndromic CDH, but there is only one mutation that has been reported in non-syndromic CDH to date. However, animal models suggest that genes involved in cell migration, myogenesis, and connective tissue formation are critical to normal diaphragm formation, and these data provide a starting point for the search for other genes involved in the pathogenesis of CDH.

A family exhibiting arterial tortuosity syndrome displays homozygosity for markers in the arterial tortuosity locus at chromosome 20q13

Arterial tortuosity associated with hyperextensible skin and hypermobility of joints, features that are characteristics of Ehlers-Danlos syndrome (EDS), has been described in several families. An arterial tortuosity locus has recently been mapped to chromosome 20q13. Here, we report a consanguineous Kurdish family in which an affected child manifested elongation and severe tortuosity of the aorta, carotid, and other arteries. Additional clinical symptoms include loose skin, hypermobile joints, hernias, and facial features that resemble EDS individuals. To examine whether the arterial tortuosity locus was involved in this child, homozygosity analysis was performed using microsatellite markers on 20q13. The affected child was found homozygous, whereas the unaffected parents and three siblings were heterozygous. Additional typing defined the genomic interval to a 37-cm region within which the arterial tortuosity locus is located. Three functional candidate genes (B4GALT5, KCNB1, and PTGIS) were sequenced. No mutations were discovered in the coding regions of these three genes and the promoter regions of B4GALT5 and KCNB1 genes. Moreover, the B4GALT5 mRNA expression was unaltered in patient-derived lymphoblastoid cells. In the PTGIS gene promoter, the affected child was homozygous for eight variable number of tandem repeats, while parents and unaffected siblings carried six repeats.