Fracture prevalence in children diagnosed with Ehlers-Danlos Syndrome and Generalized Joint Hypermobility

BACKGROUND

There is limited understanding of the hypothesized association between the Ehlers-Danlos Syndromes (EDS), hypermobility and fractures in children. Despite this, EDS and hypermobility continue to be raised in the legal setting as possible causes of unexplained fractures in infants where there is a concern for physical abuse. Further understanding is needed regarding fractures in children with EDS and hypermobility.

OBJECTIVE

This study assessed fracture prevalence and characteristics in children diagnosed with EDS and Generalized Joint Hypermobility (GJH). The secondary outcome was fracture prevalence in infants <1 year of age.

PARTICIPANTS AND SETTING

Children aged <18 years with EDS or GJH seen in a single-center EDS clinic from April 2017 to December 2021 were included. Diagnoses were based on the 2017 international classification. Exclusion criteria were concurrent medical conditions associated with bone fragility.

METHODS

This retrospective descriptive study examined variables including fracture history, fracture location, fracture type, age of sustaining fracture, and injury mechanism. Descriptive statistics were used for analysis.

RESULTS

Fracture prevalence was 34.6 % (9/26, 95 % CI [16.3, 52.9]) in the EDS population and 25.4 % (15/59, 95 % CI [14.3, 36.5]) in the GJH population. No fractures occurred in infancy. Most fractures occurred in the limbs. There were no rib or skull fractures. Most fractures were the result of an identifiable injury event.

CONCLUSION

In a cohort of children with formally diagnosed EDS or GJH, fractures occurred commonly in ambulatory children and generally in the limbs from identifiable events. This study does not support EDS or GJH as a cause of fractures in infancy.

Growing skull fracture in a child with Ehlers-Danlos syndrome: case report and literature review

INTRODUCTION

Growing skull fracture (GSF) is a rare complication of head trauma in the pediatric population, commonly observed in children younger than 3 years.

DISCUSSION

In this report, the authors describe a case of a 3-year-old male child, with clinical features of Ehlers-Danlos syndrome (EDS), who developed a GSF in frontal bone after a crib fall, treated with duraplasty and cranioplasty with autologous craft. Here, pertinent literature was reviewed with an emphasis on surgical techniques, and correlation with the mentioned syndrome.

CONCLUSION

This is the first case of GSF in association with EDS in the literature. The relevance of the case described concerns the rarity of the condition itself, the atypical presentation, and the intraoperative findings, which showed the important fragility of the dura mater, probably due to EDS. Therefore, this syndrome, besides having influenced the pathogenesis, was also a challenging factor in the surgical treatment.

Ehlers-Danlos syndrome: what the radiologist needs to know

Ehlers-Danlos syndrome is a real diagnosis that is erroneously used to explain multiple fractures in suspected child abuse. This paper reviews the clinical and molecular diagnostic criteria for Ehlers-Danlos syndrome. This knowledge can help prevent misdiagnosis and support clinicians when evaluating infants and young children with multiple fractures.

Genetic consultations in cases of unexplained fractures and haemorrhage: an evidence-based approach

PURPOSE OF REVIEW

When infants and young children present with suspected physical abuse, it is critical to follow standard guidelines and rule out alternative causes of fracture and haemorrhage. A multidisciplinary team involved in the initial evaluation typically includes paediatrics, radiology, child protective services and/or law enforcement, and in complex cases, haematology, neurology, and genetics. A comprehensive genetics consultation includes review of the history of present illness, birth and past medical history, review of growth curves, family history, physical examination, radiological findings, and when indicated, biochemical and/ or genetic testing.

RECENT FINDINGS

A number of reports have mischaracterized several genetic disorders as child abuse mimics. There is a difference between a differential diagnosis, which includes every condition that can cause a fracture and/or subdural haemorrhage, and a mimic, so called because it can be difficult to differentiate from child abuse. In this review, we discuss the differential diagnosis for infantile fractures and subdural bleeds, highlight cardinal signs and symptoms of genetic disorders, and demonstrate that these genetic disorders can be readily differentiated and diagnosed using a stepwise approach. Genetic disorders rarely, if ever, are truly mimics of child physical abuse.

SUMMARY

In cases of suspected child physical abuse, multidisciplinary evaluations by paediatric specialists, keen clinical judgment, complete physical examinations, and judicious testing provides an evidence-based, time tested approach to excluding genetic disorders and diagnosing suspected child physical abuse.

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.

Vascular phenotypes in nonvascular subtypes of the Ehlers-Danlos syndrome: a systematic review

Purpose

Within the spectrum of the Ehlers-Danlos syndromes (EDS), vascular complications are usually associated with the vascular subtype of EDS. Vascular complications are also observed in other EDS subtypes, but the reports are anecdotal and the information is dispersed. To better document the nature of vascular complications among “nonvascular” EDS subtypes, we performed a systematic review.

Methods

We queried three databases for English-language studies from inception until May 2017, documenting both phenotypes and genotypes of patients with nonvascular EDS subtypes. The outcome included the number and nature of vascular complications.

Results

A total of 112 papers were included and data were collected from 467 patients, of whom 77 presented with a vascular phenotype. Severe complications included mainly hematomas (53%), frequently reported in musculocontractural and classical-like EDS; intracranial hemorrhages (18%), with a high risk in dermatosparaxis EDS; and arterial dissections (16%), frequently reported in kyphoscoliotic and classical EDS. Other, more minor, vascular complications were reported in cardiac-valvular, arthrochalasia, spondylodysplastic, and periodontal EDS.

Conclusion

Potentially life-threatening vascular complications are a rare but important finding in several nonvascular EDS subtypes, highlighting a need for more systematic documentation. This review will help familiarize clinicians with the spectrum of vascular complications in EDS and guide follow-up and management.

Neonatal fractures as a presenting feature of LMOD3-associated congenital myopathy

Nemaline myopathy is a rare inherited disorder characterized by weakness, hypotonia, and depressed deep tendon reflexes. It is clinically and genetically heterogeneous, with the most severe phenotype presenting as perinatal akinesia, severe muscle weakness, feeding difficulties and respiratory failure, leading to early mortality. Pathogenic variants in 12 genes, encoding components of the sarcomere or factors related to myogenesis, have been reported in patients affected with the disorder. Here, we describe an early, lethal presentation of decreased fetal movements, hypotonia, muscle weakness, and neonatal respiratory failure requiring ventilator support in three siblings from a consanguineous family. All exhibited perinatal fractures, and thus, a skeletal dysplasia was considered as possibly contributing to the phenotype. However, whole exome sequencing revealed a homozygous, loss-of-function pathogenic variant in LMOD3, which has recently been associated with nemaline myopathy and, in a subset of patients, perinatal fractures. This case demonstrates the importance of considering congenital neuromuscular disorders in the differential diagnosis of perinatal fractures.

Expanding the clinical and mutational spectrum of the Ehlers-Danlos syndrome, dermatosparaxis type

PURPOSE

The Ehlers-Danlos syndrome (EDS), dermatosparaxis type, is a recessively inherited connective tissue disorder caused by deficient activity of ADAMTS-2, an enzyme that cleaves the aminoterminal propeptide domain of types I, II, and III procollagen. Only 10 EDS dermatosparaxis patients have been reported, all presenting a recognizable phenotype with characteristic facial gestalt, extreme skin fragility and laxity, excessive bruising, and sometimes major complications due to visceral and vascular fragility.

METHODS

We report on five new EDS dermatosparaxis patients and provide a comprehensive overview of the current knowledge of the natural history of this condition.

RESULTS

We identified three novel homozygous loss-of-function mutations (c.2927_2928delCT, p.(Pro976Argfs*42); c.669_670dupG, p.(Pro224Argfs*24); and c.2751-2A>T) and one compound heterozygous mutation (c.2T>C, p.? and c.884_887delTGAA, p.(Met295Thrfs26*)) in ADAMTS2 in five patients from four unrelated families. Three of these displayed a phenotype that was strikingly milder than that of previously reported patients.

CONCLUSION

This study expands the clinical and molecular spectrum of the dermatosparaxis type of EDS to include a milder phenotypic variant and stresses the importance of good clinical criteria. To address this, we propose an updated set of criteria that accurately captures the multisystemic nature of the dermatosparaxis type of EDS.Genet Med 18 9, 882-891.

Beyond osteogenesis imperfecta: Causes of fractures during infancy and childhood

Fractures in infancy or early childhood require prompt evaluation with consideration of accidental or non-accidental trauma as well as a large number of genetic disorders that predispose to fractures. Bone fragility has been reported in more than 100 genetic disorders, including skeletal dysplasias, inborn errors of metabolism and congenital insensitivity to pain. Most of these disorders are rare but often have distinctive clinical or radiographic findings to assist in the diagnosis. Gene sequencing is available, albeit connective tissue and skeletal dysplasia panels and biochemical studies are only helpful in a minority of cases. This article presents the clinical, radiographic, and molecular profiles of the most common heritable disorders other than osteogenesis imperfecta with increased bone fragility. In addition, the clinicians must consider non-heritable influences such as extreme prematurity, prenatal viral infection and neoplasia in the diagnostic process.

Genetic differentials of child abuse: Is your case rare or real?

The clinical geneticist can be called upon to play a role in the medical evaluation of children with clinical findings concerning for child abuse. This Introduction describes a case of suspected child abuse in an 8-month-old baby referred to clinical genetics to exclude osteogenesis imperfecta. The experience from this case raised medical and ethical considerations and prompted consideration of the role of the clinical geneticist in distinguishing rare mimics of child abuse from real cases. From this single case, and a discussion regarding similar cases, arose the idea of this issue in Seminars in Medical Genetics, Genetic Differentials of Child Abuse: Is Your Case Rare or Real? In thinking about child abuse from a clinical genetics perspective, we categorize clinical presentations into fractures, skin lesions, hemorrhage, growth disturbances, and concern for caregiver-fabricated illness (previously known as Munchausen syndrome by proxy). In this Introduction, we also discuss recent questions regarding Ehlers-Danlos syndrome and infantile fractures and concerns about caregiver-fabricated illness in the context of mitochondrial or other rare diseases. The goal is that this issue on child abuse and genetics will serve as a resource to help distinguish the rare causes from the real cases of child abuse, and those critical distinctions and correct diagnoses may be life-saving for some infants and children.

Bone densitometry in infants and young children: the 2013 ISCD Pediatric Official Positions

Infants and children <5 yr were not included in the 2007 International Society for Clinical Densitometry Official Positions regarding Skeletal Health Assessment of Children and Adolescents. To advance clinical care of very young children, the International Society for Clinical Densitometry 2013 Position Development Conference reviewed the literature addressing appropriate methods and skeletal sites for clinical dual-energy X-ray absorptiometry (DXA) measurements in infants and young children and how results should be reported. DXA whole-body bone mineral content and bone mineral density for children ≥3 yr and DXA lumbar spine measurements for infants and young children 0-5 yr were identified as feasible and reproducible. There was insufficient information regarding methodology, reproducibility, and reference data to recommended forearm and femur measurements at this time. Appropriate methods to account for growth delay when interpreting DXA results for children <5 yr are currently unknown. Reference data for children 0-5 yr at multiple skeletal sites are insufficient and are needed to enable interpretation of DXA measurements. Given the current scarcity of evidence in many areas, it is likely that these positions will change over time as new data become available.

Further Evidence of Contrasting Phenotypes Caused by Reciprocal Deletions and Duplications: Duplication of NSD1 Causes Growth Retardation and Microcephaly

Microduplications of the Sotos syndrome region containing NSD1 on 5q35 have recently been proposed to cause a syndrome of microcephaly, short stature and developmental delay. To further characterize this emerging syndrome, we report the clinical details of 12 individuals from 8 families found to have interstitial duplications involving NSD1, ranging in size from 370 kb to 3.7 Mb. All individuals are microcephalic, and height and childhood weight range from below average to severely restricted. Mild-to-moderate learning disabilities and/or developmental delay are present in all individuals, including carrier family members of probands; dysmorphic features and digital anomalies are present in a majority. Craniosynostosis is present in the individual with the largest duplication, though the duplication does not include MSX2, mutations of which can cause craniosynostosis, on 5q35.2. A comparison of the smallest duplication in our cohort that includes the entire NSD1 gene to the individual with the largest duplication that only partially overlaps NSD1 suggests that whole-gene duplication of NSD1 in and of itself may be sufficient to cause the abnormal growth parameters seen in these patients. NSD1 duplications may therefore be added to a growing list of copy number variations for which deletion and duplication of specific genes have contrasting effects on body development.

Prenatal diagnosis and management of intrauterine fracture

Intrauterine fracture is an extremely rare finding, but can occur as the result of maternal trauma, osteogenesis imperfecta (OI), or theoretically other metabolic/structural abnormalities. Increased clinical awareness of the diagnosis and optimal management of these cases can lead to more positive outcomes for the patient and her child. Blunt abdominal trauma late in gestation increases the risk of fetal skull fracture, while a known diagnosis of OI or other abnormalities leading to decreased fetal bone density creates concern for long bone fracture. Biochemical and genetic tests can aid in the prenatal diagnosis of OI, while ultrasound is the best overall imaging modality for identifying fetal fracture of any etiology. When fetal fracture is diagnosed radiologically, specific management is recommended to promote optimal outcomes for mother and fetus, with special consideration given to the mother with OI. With the exception of fetal fractures due to lethal conditions, cesarean delivery is recommended in most cases, especially when fetal or maternal well-being cannot be assured. When a patient presents with risk factors for intrauterine fracture, careful evaluation via thorough history-taking, ultrasonography of the entire fetal skeleton, and laboratory tests should be performed. Heightened awareness of intrauterine fracture allows better postpartum management, whether for simple fracture care or for long-term care of patients with OI or genetic/metabolic abnormalities.

TARGET AUDIENCE

Obstetricians & Gynecologist, Family Physicians.

LEARNING OBJECTIVES

After completion of this educational activity, the reader will be able to compare x-ray, ultrasound modalities and MRI and their utility in diagnosing fetal fracture. Formulate a differential diagnosis for fetal fracture. Propose a delivery plan for a patient whose fetus has a prenatally diagnosed fetal fracture.