Combination therapy of DDAVP and conjugated estrogens for a recurrent large subcutaneous hematoma in Ehlers-Danlos syndrome

Rhegmatogenous Retinal Detachment in Musculocontractural Ehlers-Danlos Syndrome Caused by Biallelic Loss-of-Function Variants of Gene for Dermatan Sulfate Epimerase

Musculocontractural Ehlers-Danlos syndrome, caused by biallelic loss-of-function variants for dermatan sulfate epimerase (mcEDS-DSE), is a rare connective tissue disorder. Eight patients with mcEDS-DSE have been described with ocular complications, including blue sclera, strabismus, high refractive errors, and elevated intraocular pressure. However, a case with rhegmatogenous retinal detachment (RRD) has not been reported. We report our findings in a 24-year-old woman who was diagnosed with mcEDS-DSE in childhood and presented to our clinic with an RRD in the left eye. The RRD extended to the macula and was associated with an atrophic hole. The patient underwent scleral buckling surgery and cryopexy with drainage of subretinal fluid through a sclerotomy under local anesthesia. The sclera did not appear blue but was very thin at the sclerotomy site. The patient developed frequent bradycardia during the surgery. Subretinal or choroidal hemorrhages were not observed intraoperatively; however, a peripapillary hemorrhage was observed one day after operation. The retina was reattached postoperatively, and the peripapillary hemorrhage was absorbed after one month. The peripapillary retinal hemorrhages, thin sclera, and bradycardia were most likely due to the fragility of the eye. The genetic diagnosis of mcEDS-DSE played an important role before and during the surgery by alerting the surgeons to possible surgical complications due to the thin sclera.

Ehlers Danlos Syndrome with Glycosaminoglycan Abnormalities

Ehlers-Danlos syndrome (EDS) is a genetically and clinically heterogeneous group of connective tissue disorders that typically present with skin hyperextensibility, joint hypermobility, and tissue fragility. The major cause of EDS appears to be impaired biosynthesis and enzymatic modification of collagen. In this chapter, we discuss two types of EDS that are associated with proteoglycan abnormalities: spondylodysplastic EDS and musculocontractural EDS. Spondylodysplastic EDS is caused by pathogenic variants in B4GALT7 or B3GALT6, both of which encode key enzymes that initiate glycosaminoglycan synthesis. Musculocontractural EDS is caused by mutations in CHST14 or DSE, both of which encode enzymes responsible for the post-translational biosynthesis of dermatan sulfate. The clinical and molecular characteristics of both types of EDS are described in this chapter.

Clinical and molecular features of 66 patients with musculocontractural Ehlers-Danlos syndrome caused by pathogenic variants in CHST14 (mcEDS-CHST14)

BACKGROUND

Musculocontractural Ehlers-Danlos syndrome is caused by biallelic loss-of-function variants in CHST14 (mcEDS-CHST14) or DSE (mcEDS-DSE). Although 48 patients in 33 families with mcEDS-CHST14 have been reported, the spectrum of pathogenic variants, accurate prevalence of various manifestations and detailed natural history have not been systematically investigated.

METHODS

We collected detailed and comprehensive clinical and molecular information regarding previously reported and newly identified patients with mcEDS-CHST14 through international collaborations.

RESULTS

Sixty-six patients in 48 families (33 males/females; 0-59 years), including 18 newly reported patients, were evaluated. Japanese was the predominant ethnicity (27 families), associated with three recurrent variants. No apparent genotype-phenotype correlation was noted. Specific craniofacial (large fontanelle with delayed closure, downslanting palpebral fissures and hypertelorism), skeletal (characteristic finger morphologies, joint hypermobility, multiple congenital contractures, progressive talipes deformities and recurrent joint dislocation), cutaneous (hyperextensibility, fine/acrogeria-like/wrinkling palmar creases and bruisability) and ocular (refractive errors) features were observed in most patients (>90%). Large subcutaneous haematomas, constipation, cryptorchidism, hypotonia and motor developmental delay were also common (>80%). Median ages at the initial episode of dislocation or large subcutaneous haematoma were both 6 years. Nine patients died; their median age was 12 years. Several features, including joint and skin characteristics (hypermobility/extensibility and fragility), were significantly more frequent in patients with mcEDS-CHST14 than in eight reported patients with mcEDS-DSE.

CONCLUSION

This first international collaborative study of mcEDS-CHST14 demonstrated that the subtype represents a multisystem disorder with unique set of clinical phenotypes consisting of multiple malformations and progressive fragility-related manifestations; these require lifelong, multidisciplinary healthcare approaches.

Systematic investigation of the skin in Chst14-/- mice: A model for skin fragility in musculocontractural Ehlers-Danlos syndrome caused by CHST14 variants (mcEDS-CHST14)

Loss-of-function variants in CHST14 cause a dermatan 4-O-sulfotransferase deficiency named musculocontractural Ehlers-Danlos syndrome-CHST14 (mcEDS-CHST14), resulting in complete depletion of the dermatan sulfate moiety of decorin glycosaminoglycan (GAG) chains, which is replaced by chondroitin sulfate. Recently, we uncovered structural alteration of GAG chains in the skin of patients with mcEDS-CHST14. Here, we conducted the first systematic investigation of Chst14 gene-deleted homozygote (Chst14-/-) mice. We used skin samples of wild-type (Chst14+/+) and Chst14-/- mice. Mechanical fragility of the skin was measured with a tensile test. Pathology was observed using light microscopy, decorin immunohistochemistry and electron microscopy (EM) including cupromeronic blue (CB) staining. Quantification of chondroitin sulfate and dermatan sulfate was performed using enzymatic digestion followed by anion-exchange HPLC. In Chst14-/- mice, skin tensile strength was significantly decreased compared with that in Chst14+/+ mice. EM showed that collagen fibrils were oriented in various directions to form disorganized collagen fibers in the reticular layer. Through EM-based CB staining, rod-shaped linear GAG chains were found to be attached at one end to collagen fibrils and protruded outside of the fibrils, in contrast to them being round and wrapping the collagen fibrils in Chst14+/+ mice. A very low level of dermatan sulfate disaccharides was detected in the skin of Chst14-/- mice by anion-exchange chromatography. Chst14-/- mice, exhibiting similar abnormalities in the GAG structure of decorin and collagen networks in the skin, could be a reasonable model for skin fragility of patients with mcEDS-CHST14, shedding light on the role of dermatan sulfate in maintaining skin strength.

Recent Advances in the Pathophysiology of Musculocontractural Ehlers-Danlos Syndrome

Musculocontractural Ehlers–Danlos Syndome (mcEDS) is a type of EDS caused by biallelic pathogenic variants in the gene for carbohydrate sulfotransferase 14/dermatan 4-O-sulfotransferase 1 (CHST14/D4ST1, mcEDS-CHST14), or in the gene for dermatan sulfate epimerase (DSE, mcEDS-DSE). Thus far, 41 patients from 28 families with mcEDS-CHST14 and five patients from four families with mcEDS-DSE have been described in the literature. Clinical features comprise multisystem congenital malformations and progressive connective tissue fragility-related manifestations. This review outlines recent advances in understanding the pathophysiology of mcEDS. Pathogenic variants in CHST14 or DSE lead to reduced activities of relevant enzymes, resulting in a negligible amount of dermatan sulfate (DS) and an excessive amount of chondroitin sulfate. Connective tissue fragility is presumably attributable to a compositional change in the glycosaminoglycan chains of decorin, a major DS-proteoglycan in the skin that contributes to collagen fibril assembly. Collagen fibrils in affected skin are dispersed in the papillary to reticular dermis, whereas those in normal skin are regularly and tightly assembled. Glycosaminoglycan chains are linear in affected skin, stretching from the outer surface of collagen fibrils to adjacent fibrils; glycosaminoglycan chains are curved in normal skin, maintaining close contact with attached collagen fibrils. Homozygous (Chst14^−/−) mice have been shown perinatal lethality, shorter fetal length and vessel-related placental abnormalities. Milder phenotypes in mcEDS-DSE might be related to a smaller fraction of decorin DS, potentially through residual DSE activity or compensation by DSE2 activity. These findings suggest critical roles of DS and DS-proteoglycans in the multisystem development and maintenance of connective tissues, and provide fundamental evidence to support future etiology-based therapies.

Spinal manifestations in 12 patients with musculocontractural Ehlers-Danlos syndrome caused by CHST14/D4ST1 deficiency (mcEDS-CHST14)

Musculocontractural Ehlers-Danlos syndrome caused by mutations in CHST14 (mcEDS-CHST14) is a recently delineated disorder, characterized by craniofacial, skeletal, visceral, and ocular malformations; and progressive cutaneous, skeletal, vascular, and visceral fragility-related manifestations. Spinal lesions, though one of the most serious complications, have not been investigated systematically. In this study, we report detailed and comprehensive information about spinal lesions of 12 patients with a mean age at the first visit of 13.4 years. Eight patients (66.7%) had scoliosis with a Cobb angle ≥10°, including one with severe scoliosis with a Cobb angle ≥45°. Five patients (41.7%) had kyphosis at the thoracolumbar junction with a kyphotic angle ≥20°. Three patients (25%) developed severe thoracolumbar kyphosis with a kyphotic angle ≥50° accompanied by thoracic lordosis with a wedge-like vertebral deformity and anterior vertebral osteophyte at the thoracolumbar junction, and two of them underwent surgical correction: complicated by fistula formation in one and performed safely and effectively through two-staged operation in the other. Six patients (50.0%) had cervical kyphosis, all of whom except one had kyphosis ≥20° at the thoracolumbar level. Two patients (16.7%) had atlantoaxial subluxation, and 10 patients (83.3%) had cervical vertebral malformations. Patients with mcEDS-CHST14 are susceptible to develop scoliosis, thoracolumbar kyphosis, and cervical kyphosis; and are recommended to have regular surveillance including total spine radiology. The present findings also suggest the critical role of dermatan sulfate in the development and maintenance of the spine.

Testicular torsion in a patient with Ehlers-Danlos syndrome

We present a 19-year-old man with a diagnosis of Ehlers-Danlos syndrome (EDS) and a delayed presentation of testicular torsion. EDS is a rare and heterogeneous condition affecting collagen synthesis and presents multiple difficulties in a surgical setting. Management of this case of testicular torsion was complicated by impaired cognition of the patient, difficulty with intubation, a contralateral undescended testis and postoperative bleeding. We discuss the specific challenges faced in this case of testicular torsion with longstanding ischaemia and perioperative considerations of EDS.

The Ehlers-Danlos syndromes, rare types

The Ehlers-Danlos syndromes comprise a clinically and genetically heterogeneous group of heritable connective tissue disorders, which are characterized by joint hypermobility, skin hyperextensibility, and tissue friability. In the Villefranche Nosology, six subtypes were recognized: The classical, hypermobile, vascular, kyphoscoliotic, arthrochalasis, and dermatosparaxis subtypes of EDS. Except for the hypermobile subtype, defects had been identified in fibrillar collagens or in collagen-modifying enzymes. Since 1997, a whole spectrum of novel, clinically overlapping, rare EDS-variants have been delineated and genetic defects have been identified in an array of other extracellular matrix genes. Advances in molecular testing have made it possible to now identify the causative mutation for many patients presenting these phenotypes. The aim of this literature review is to summarize the current knowledge on the rare EDS subtypes and highlight areas for future research. © 2017 Wiley Periodicals, Inc.

CHST14/D4ST1 deficiency: New form of Ehlers-Danlos syndrome

Carbohydrate sulfotransferase 14/dermatan 4-O-sulfotransferase-1 (CHST14/D4ST1) deficiency represents a specific form of Ehlers-Danlos syndrome (EDS) caused by recessive loss-of-function mutations in CHST14. The disorder has been independently termed "adducted thumb-clubfoot syndrome", "EDS, Kosho type", and "EDS, musculocontractural type". To date, 31 affected patients from 21 families have been described. Clinically, CHST14/D4ST1 deficiency is characterized by multiple congenital malformations (craniofacial features including large fontanelle, hypertelorism, short and downslanting palpebral fissures, blue sclerae, short nose with hypoplastic columella, low-set and rotated ears, high palate, long philtrum, thin upper lip vermilion, small mouth, and micro-retrognathia; multiple congenital contractures including adduction-flexion contractures and talipes equinovarus as well as other visceral or ophthalmological malformations) and progressive multisystem fragility-related complications (skin hyperextensibility, bruisability, and fragility with atrophic scars; recurrent dislocations; progressive talipes or spinal deformities; pneumothorax or pneumohemothorax; large subcutaneous hematomas; and diverticular perforation). Etiologically, multisystem fragility is presumably caused by impaired assembly of collagen fibrils resulting from loss of dermatan sulfate (DS) in the decorin glycosaminoglycan side chain that promotes electrostatic binding between collagen fibrils. This is the first reported human disorder that specifically affects biosynthesis of DS. Its clinical characteristics indicate that CHST14/D4ST1 and, more fundamentally, DS, play a critical role in fetal development and maintenance of connective tissues in multiple organs. Considering that patients with CHST14/D4ST1 deficiency develop progressive multisystem fragility-related manifestations, establishment of a comprehensive and detailed natural history and health-care guidelines as well as further elucidation of the pathophysiology in view of future etiology-based therapy are crucial.

Genetic heterogeneity and clinical variability in musculocontractural Ehlers-Danlos syndrome caused by impaired dermatan sulfate biosynthesis

Bi-allelic variants in CHST14, encoding dermatan 4-O-sulfotransferase-1 (D4ST1), cause musculocontractural Ehlers-Danlos syndrome (MC-EDS), a recessive disorder characterized by connective tissue fragility, craniofacial abnormalities, congenital contractures, and developmental anomalies. Recently, the identification of bi-allelic variants in DSE, encoding dermatan sulfate epimerase-1 (DS-epi1), in a child with MC-EDS features, suggested locus heterogeneity for this condition. DS-epi1 and D4ST1 are crucial for biosynthesis of dermatan sulfate (DS) moieties in the hybrid chondroitin sulfate (CS)/DS glycosaminoglycans (GAGs). Here, we report four novel families with severe MC-EDS caused by unique homozygous CHST14 variants and the second family with a homozygous DSE missense variant, presenting a somewhat milder MC-EDS phenotype. The glycanation of the dermal DS proteoglycan decorin is impaired in fibroblasts from D4ST1- as well as DS-epi1-deficient patients. However, in D4ST1-deficiency, the decorin GAG is completely replaced by CS, whereas in DS-epi1-deficiency, still some DS moieties are present. The multisystemic abnormalities observed in our patients support a tight spatiotemporal control of the balance between CS and DS, which is crucial for multiple processes including cell differentiation, organ development, cell migration, coagulation, and connective tissue integrity.

Recommendations for anesthesia and perioperative management in patients with Ehlers-Danlos syndrome(s)

Ehlers-Danlos syndrome (EDS, ORPHA98249) comprises a group of clinically and genetically heterogeneous heritable connective tissue disorders, chiefly characterized by joint hypermobility and instability, skin texture anomalies, and vascular and soft tissue fragility. As many tissues can be involved, the underlying molecular defect can manifest itself in many organs and with varying degrees of severity, with widespread implications for anesthesia and perioperative management. This review focuses on issues relevant for anesthesia for elective and emergency surgery in EDS. We searched the literature for papers related to all EDS variants; at the moment most of the published data deals with the vascular subtype and, to a lesser extent, classic and hypermobility EDS. Knowledge is fragmented and consists mostly of case reports, small case series and expert opinion. Because EDS patients commonly require surgery, we have summarized some recommendations for general, obstetrical and regional anesthesia, as well as for hemostatic therapy.

A new Ehlers-Danlos syndrome with craniofacial characteristics, multiple congenital contractures, progressive joint and skin laxity, and multisystem fragility-related manifestations

We previously described two unrelated patients showing characteristic facial and skeletal features, overlapping with the kyphoscoliosis type Ehlers-Danlos syndrome (EDS) but without lysyl hydroxylase deficiency [Kosho et al. (2005) Am J Med Genet Part A 138A:282-287]. After observations of them over time and encounter with four additional unrelated patients, we have concluded that they represent a new clinically recognizable type of EDS with distinct craniofacial characteristics, multiple congenital contractures, progressive joint and skin laxity, and multisystem fragility-related manifestations. The patients exhibited strikingly similar features according to their age: craniofacial, large fontanelle, hypertelorism, short and downslanting palpebral fissures, blue sclerae, short nose with hypoplastic columella, low-set and rotated ears, high palate, long philtrum, thin vermilion of the upper lip, small mouth, and micro-retrognathia in infancy; slender and asymmetric face with protruding jaw from adolescence; skeletal, congenital contractures of fingers, wrists, and hips, and talipes equinovarus with anomalous insertions of flexor muscles; progressive joint laxity with recurrent dislocations; slender and/or cylindrical fingers and progressive talipes valgus and cavum or planus, with diaphyseal narrowing of phalanges, metacarpals, and metatarsals; pectus deformities; scoliosis or kyphoscoliosis with decreased physiological curvatures of thoracic spines and tall vertebrae; cutaneous, progressive hyperextensibility, bruisability, and fragility with atrophic scars; fine palmar creases in childhood to acrogeria-like prominent wrinkles in adulthood, recurrent subcutaneous infections with fistula formation; cardiovascular, cardiac valve abnormalities, recurrent large subcutaneous hematomas from childhood; gastrointestinal, constipation, diverticula perforation; respiratory, (hemo)pneumothorax; and ophthalmological, strabismus, glaucoma, refractive errors.

Loss-of-function mutations of CHST14 in a new type of Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) is a heterogeneous connective tissue disorder involving skin and joint laxity and tissue fragility. A new type of EDS, similar to kyphoscoliosis type but without lysyl hydroxylase deficiency, has been investigated. We have identified a homozygous CHST14 (carbohydrate sulfotransferase 14) mutation in the two familial cases and compound heterozygous mutations in four sporadic cases. CHST14 encodes dermatan 4-O-sulfotransferase 1 (D4ST1), which transfers active sulfate from 3'-phosphoadenosine 5'-phosphosulfate to position 4 of the N-acetyl-D-galactosamine (GalNAc) residues of dermatan sulfate (DS). Transfection experiments of mutants and enzyme assays using fibroblast lysates of patients showed the loss of D4ST1 activity. CHST14 mutations altered the glycosaminoglycan (GAG) components in patients' fibroblasts. Interestingly, DS of decorin proteoglycan, a key regulator of collagen fibril assembly, was completely lost and replaced by chondroitin sulfate (CS) in the patients' fibroblasts, leading to decreased flexibility of GAG chains. The loss of the decorin DS proteoglycan due to CHST14 mutations may preclude proper collagen bundle formation or maintenance of collagen bundles while the sizes and shapes of collagen fibrils are unchanged as observed in the patients' dermal tissues. These findings indicate the important role of decorin DS in the extracellular matrix and a novel pathomechanism in EDS.

The use of desmopressin as a hemostatic agent: a concise review

Desmopressin, a synthetic derivative of the antidiuretic hormone vasopressin, is the treatment of choice for most patients with von Willebrand disease and mild hemophilia A. Moreover, the compound has been shown to be useful in a variety of inherited and acquired hemorrhagic conditions, including some congenital platelet function defects, chronic liver disease, uremia, and hemostatic defects induced by the therapeutic use of antithrombotic drugs such as aspirin and ticlopidine. Finally, desmopressin has been used as a blood saving agent in patients undergoing operations characterized by large blood loss and transfusion requirements, but studies suggest that this is not as effective as other methods. This review briefly summarizes the current clinical indications on the use of desmopressin as a hemostatic agent.

The vascular Ehlers-Danlos syndrome

Vascular Ehlers-Danlos syndrome (EDS) is a life-threatening inherited disorder of connective tissue causing severe arterial and gastrointestinal fragility and rupture, as well as complications of surgical and radiologic interventions. The diagnosis should be considered in patients under the age of 45 years who present with arterial tearing or dissection, colonic perforation, or visceral rupture. As for many orphan diseases, delayed diagnosis can lead to inaccurate care. Therefore, vascular EDS is particularly important to surgeons, radiologists, and obstetricians because knowledge of the diagnosis may help in the management of visceral complications. There are currently no specific treatments for this genetic condition, and medical intervention is limited to symptomatic treatment, precautionary measures, genetic counseling, and prenatal diagnosis. A clinical trial is ongoing to study the effectiveness of beta blockers with vasodilating properties in vascular EDS. Complications require hospitalization, observation in an intensive care unit, and sometimes emergency surgical intervention. CT, echography, and MRI are the most useful imaging modalities. Arteriography is contraindicated. Whenever possible, a wait-and-see attitude with close surveillance is preferable to unwarranted surgery. Surgical treatment carries a high mortality, whereas the mortality rate associated with endovascular treatment is unknown. To improve the likelihood of good surgical outcome, the surgeon must be informed of the patient's condition. The intent of surgery is to control hemorrhage if an artery, with or without aneurysm, has ruptured and to reconstruct the arterial vasculature. For vascular repair, simple procedures should be preferred, because more complex techniques can result in further injury and hemorrhage. Postoperative surveillance must be prolonged with close medical follow-up and serial CT scans. Pregnant women with vascular EDS should be considered high-risk cases and be provided special care.