Genetic evaluation of suspected osteogenesis imperfecta (OI)

A De novo Mutation in the COL1A1 Gene Leading to Severe Osteogenesis Imperfecta: Case Report and Review of the Literature

Introduction  Osteogenesis imperfecta (OI) is the most common monogenic inherited skeletal dysplasia disorder. Mutations in the COL1A1/COL1A2 gene cause ∼85 to 90% of OI. Studies of cases have demonstrated that missense mutations are the primary cause of OI, with poor prognosis. Case Description  We report the case of a fetus with skeletal abnormalities and subcutaneous edema. Ultrasound imaging revealed suspected skeletal malformations, including hypoplastic long bones of all four limbs, poorly ossified calvarium, unrevealing nasal bones, and generalized subcutaneous edema. Whole-exome sequencing revealed a heterozygous mutation in COL1A1 (c.2174G > T/p.(G725V), NM_000088.3). According to the American College of Medical Genetics and Genomics guidelines, it was determined to be a pathogenic variant and identified as a de novo variant (PS2 + PP3_strong + PM2_supporting), which has not been reported in the HGMD, gnomAD, ClinVar, or other databases. This variation causes a glycine-to-valine substitution at position 725, located within the Gly-Xaa-Yaa repeat in the helical domain of the collagen molecule. Conclusion  The COL1A1 mutation (c.2174G > T/p.(G725V), NM_000088.3) is a novel pathogenic variant of severe OI. Our study expanded the OI COL1A1 gene variation profiles in the Chinese population and provided a theoretical foundation for prenatal diagnosis, genetic counseling, and obstetric management.

Association of Antenatal Evaluations with Postmortem and Genetic Findings in the Series of Fetal Osteogenesis Imperfecta

INTRODUCTION

Counseling osteogenesis imperfecta (OI) pregnancies is challenging due to the wide range of onsets and clinical severities, from perinatal lethality to milder forms detected later in life.

METHODS

Thirty-eight individuals from 36 families were diagnosed with OI through prenatal ultrasonography and/or postmortem clinical and radiographic findings. Genetic analysis was conducted on 26 genes associated with OI in these subjects that emerged over the past 20 years; while some genes were examined progressively, all 26 genes were examined in the group where no pathogenic variations were detected.

RESULTS

Prenatal and postnatal observations both consistently showed short limbs in 97%, followed by bowing of the long bones in 89%. Among 32 evaluated cases, all exhibited cranial hypomineralization. Fractures were found in 29 (76%) cases, with multiple bones involved in 18 of them. Genetic associations were disclosed in 27 families with 22 (81%) autosomal dominant and five (19%) autosomal recessive forms, revealing 25 variants in six genes (COL1A1, COL1A2, CREB3L1, P3H1, FKBP10, and IFITM5), including nine novels. Postmortem radiological examination showed variability in intrafamily expression of CREBL3- and P3H1-related OI.

CONCLUSION

Prenatal diagnosis for distinguishing OI and its subtypes relies on factors such as family history, timing, ultrasound, genetics, and postmortem evaluation.

Emerging Landscape of Osteogenesis Imperfecta Pathogenesis and Therapeutic Approaches

Osteogenesis imperfecta (OI) is an uncommon genetic disorder characterized by shortness of stature, hearing loss, poor bone mass, recurrent fractures, and skeletal abnormalities. Pathogenic variations have been found in over 20 distinct genes that are involved in the pathophysiology of OI, contributing to the disorder's clinical and genetic variability. Although medications, surgical procedures, and other interventions can partially alleviate certain symptoms, there is still no known cure for OI. In this Review, we provide a comprehensive overview of genetic pathogenesis, existing treatment modalities, and new developments in biotechnologies such as gene editing, stem cell reprogramming, functional differentiation, and transplantation for potential future OI therapy.

A Sporadic Case of COL1A1 Osteogenesis Imperfecta: From Prenatal Diagnosis to Outcomes in Infancy-Case Report and Literature Review

Osteogenesis imperfecta (OI), also known as brittle bone disease, belongs to a rare heterogeneous group of inherited connective tissue disorders. In experienced prenatal centers, severe cases of OI can be suspected before birth from the first trimester prenatal ultrasound screening. In this article, we describe a case report of OI suspected at the 26th week of gestation and the patient's outcomes in infancy one year after birth, as well as compare our case to other prenatally or soon-after-birth suspected and/or diagnosed OI clinical case reports in the literature. This case was managed by a multidisciplinary team. In this clinical case, OI was first suspected when prenatal ultrasound revealed asymmetric intrauterine growth restriction and skeletal dysplasia features. The diagnosis was confirmed after birth using COL1A1 gene variant detection via exome sequencing; the COL1A1 gene variant causes OI types I-IV. The familial history was negative for both pregnancy-related risk factors and genetic diseases. At one year old, the patient's condition remains severe with bisphosphonate therapy.

The patient clinical journey and socioeconomic impact of osteogenesis imperfecta: a systematic scoping review

BACKGROUND

Osteogenesis imperfecta (OI) is a rare heritable connective tissue disorder primarily characterised by skeletal deformity and fragility, and an array of secondary features. The purpose of this review was to capture and quantify the published evidence relating specifically to the clinical, humanistic, and economic impact of OI on individuals, their families, and wider society.

METHODS

A systematic scoping review of 11 databases (MEDLINE, MEDLINE in-progress, EMBASE, CENTRAL, PsycINFO, NHS EED, CEA Registry, PEDE, ScHARRHUd, Orphanet and Google Scholar), supplemented by hand searches of grey literature, was conducted to identify OI literature published 1st January 1995-18th December 2021. Searches were restricted to English language but without geographical limitations. The quality of included records was assessed using the AGREE II checklist and an adapted version of the JBI cross-sectional study checklist.

RESULTS

Of the identified 7,850 records, 271 records of 245 unique studies met the inclusion criteria; overall, 168 included records examined clinical aspects of OI, 67 provided humanistic data, 6 reported on the economic impact of OI, and 30 provided data on mixed outcomes. Bone conditions, anthropometric measurements, oral conditions, diagnostic techniques, use of pharmacotherapy, and physical functioning of adults and children with OI were well described. However, few records included current care practice, diagnosis and monitoring, interactions with the healthcare system, or transition of care across life stages. Limited data on wider health concerns beyond bone health, how these concerns may impact health-related quality of life, in particular that of adult men and other family members, were identified. Few records described fatigue in children or adults. Markedly few records provided data on the socioeconomic impact of OI on patients and their caregivers, and associated costs to healthcare systems, and wider society. Most included records had qualitative limitations.

CONCLUSION

Despite the rarity of OI, the volume of recently published literature highlights the breadth of interest in the OI field from the research community. However, significant data gaps describing the experience of OI for individuals, their families, and wider society warrant further research to capture and quantify the full impact of OI.

Osteogenesis Imperfecta: A Case Series and Literature Review

Osteogenesis imperfecta (OI) is a hereditary disease of connective tissue characterized by the loss of bone density and mass, which increases the fragility of the bones, thus presenting multiple fractures throughout the years followed by bone deformity and articular instability. This condition has various clinical presentations. We present four cases of OI, one case with type I, two cases with type II, and one case with type III. The clinical diagnosis in most of the cases was clinical; only one of them was confirmed with genomic sequence. The treatment of these cases was based on medication, orthopedic surgery, and recovery and physical therapy. The evolution was torpid in these cases but with prolonged life expectancy despite the severity and type of OI. It is important to highlight that the patients did not have a neurocognitive compromise. Early diagnosis and multidisciplinary medical management are crucial in obtaining better outcomes for this disease, improving the quality of life, and avoiding complications.

COL1A2 (p.Gly322Ser) Mutation Causes Late-Onset Osteogenesis Imperfecta: A Case Report

Osteogenesis imperfecta (OI) is a genetically inherited disorder that mainly affects the bones and causes a generalized decrease in bone mass. OI has a broad clinical spectrum ranging from the most severe form of OI which may cause in-utero death or stillbirth to the milder form. Clinical manifestations normally mitigate with an increase in age. We report a case of a healthy 12-year-old male who presented with a spontaneous fracture of the femur without trauma. The patient has no previous history of fractures, bone deformities or systemic conditions. The initial physical examination was unremarkable except for a bilateral subtle grayish sclera. Calcium, phosphorus, vitamin D, blood urea nitrogen (BUN), creatinine, and parathyroid hormone (PTH) values were within normal range. After genetic testing, the patient was diagnosed with OI due to a pathogenic COL1A2 (c.964G>A [p.Gly322Ser]) mutation. The first manifestation was at 12 years of age with a femur spontaneous fracture, which brings to the fact that the patient has a late onset of OI.

Early-Onset Osteoporosis: Rare Monogenic Forms Elucidate the Complexity of Disease Pathogenesis Beyond Type I Collagen

Early-onset osteoporosis (EOOP), characterized by low bone mineral density (BMD) and fractures, affects children, premenopausal women and men aged <50 years. EOOP may be secondary to a chronic illness, long-term medication, nutritional deficiencies, etc. If no such cause is identified, EOOP is regarded primary and may then be related to rare variants in genes playing a pivotal role in bone homeostasis. If the cause remains unknown, EOOP is considered idiopathic. The scope of this review is to guide through clinical and genetic diagnostics of EOOP, summarize the present knowledge on rare monogenic forms of EOOP, and describe how analysis of bone biopsy samples can lead to a better understanding of the disease pathogenesis. The diagnostic pathway of EOOP is often complicated and extensive assessments may be needed to reliably exclude secondary causes. Due to the genetic heterogeneity and overlapping features in the various genetic forms of EOOP and other bone fragility disorders, the genetic diagnosis usually requires the use of next-generation sequencing to investigate several genes simultaneously. Recent discoveries have elucidated the complexity of disease pathogenesis both regarding genetic architecture and bone tissue-level pathology. Two rare monogenic forms of EOOP are due to defects in genes partaking in the canonical WNT pathway: LRP5 and WNT1. Variants in the genes encoding plastin-3 (PLS3) and sphingomyelin synthase 2 (SGMS2) have also been found in children and young adults with skeletal fragility. The molecular mechanisms leading from gene defects to clinical manifestations are often not fully understood. Detailed analysis of patient-derived transiliac bone biopsies gives valuable information to understand disease pathogenesis, distinguishes EOOP from other bone fragility disorders, and guides in patient management, but is not widely available in clinical settings. Despite the great advances in this field, EOOP remains an insufficiently explored entity and further research is needed to optimize diagnostic and therapeutic approaches. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Clinical genetics evaluation and testing of connective tissue disorders: a cross-sectional study

BACKGROUND

Heritable connective tissue disorders (HCTDs) consist of heterogeneous syndromes. The diagnosis of HCTDs is aided by genomic biotechnologies (e.g., next-generation sequencing panels) facilitating the discovery of novel variants causing disease.

METHODS

Detailed clinical exam data and CLIA-approved genetic testing results from next generation sequencing of 74 genes known to play a role in HCTDs were manually reviewed and analyzed in one hundred consecutive, unrelated patients with phenotypic features indicative of a HCTD referred over a 3.5-year period (2016-2020) to a specialized academic genetics clinic. The prevalence of symptoms was evaluated in the context of genetic variants. We also determined if symptoms among different organ systems were related and performed latent class analysis to identify distinct groups of patients based on symptomatology.

RESULTS

In the cohort of 100 consecutive, unrelated individuals there were four pathogenic, six likely pathogenic and 35 classified potentially pathogenic variants of unknown clinical significance. Patients with potentially pathogenic variants exhibited similar symptom profiles when compared to patients with pathogenic/likely pathogenic variants in the same genes. Although results did not meet a multiple testing corrected threshold, patients with connective tissue symptoms had suggestive evidence of increased odds of having skin (odds ratio 2.18, 95% confidence interval 1.12 to 4.24) and eye symptoms (odds ratio 1.89, 95% confidence interval 0.98 to 3.66) requiring further studies. The best performing latent class analysis results were identified when dividing the dataset into three distinct groups based on age, gender and presence or absence of symptoms in the skeletal, connective tissue, nervous, gastrointestinal and cardiovascular systems. These distinct classes of patients included individuals with: (1) minimal skeletal symptoms, (2) more skeletal but fewer connective tissue, nervous or gastrointestinal symptoms and (3) more nervous system symptoms.

CONCLUSIONS

We used novel approaches to characterize phenotype-genotype relationships, including pinpointing potentially pathogenic variants, and detecting unique symptom profiles in patients with features of HCTDs. This study may guide future diagnosis and disease/organ system monitoring with continued improvement and surveillance by clinicians for patients and their families.

Surgical Strategy to Decrease the Revision Rate of Fassier-Duval Nailing in the Lower Limbs of Osteogenesis Imperfecta

(1) Background: The Fassier−Duval (FD) nail was developed for the treatment of osteogenesis imperfecta (OI). The aim of this study was to review the results of OI patients treated with the FD nail at our institution and discuss a surgical strategy to decrease the FD nail revision rate; (2) Methods: We retrospectively reviewed OI patients treated at our institution between 2015 and 2020. OI patients treated with FD nail insertion in the long bones of the lower extremities were included, and those with a follow-up duration <1 year or incomplete radiographs were excluded. Data on the type of OI, age, sex, use of bisphosphonate treatment, and nail failure were recorded; (3) Results: The final cohort consisted of seven patients (three females and four males) with ten femurs and ten tibiae involved. Six of the patients had type III OI, and one had type IV OI. An exchange of implant was required in 11 limbs. The average interval between previous FD nail insertion and revision surgery was 2.4 years; (4) Discussion: The main reasons for revision surgery were migration of the male/female component, refracture/nail bending, and delayed union. In the femur, migration of the female component or nail bending were common reasons for failure, while migration of the male component and delayed union were common in the tibia; (5) Conclusions: Surgery for OI patients is challenging, and physicians should aim to minimize complications and the need for revision. Sufficient depth of purchase, center−center nail position, and adequate osteotomy to correct bowing are the key factors when using the FD nail.

Osteogenesis Imperfecta/Ehlers-Danlos Overlap Syndrome and Neuroblastoma-Case Report and Review of Literature

Osteogenesis imperfecta/Ehlers−Danlos (OI/EDS) overlap syndrome is a recently described disorder of connective tissue, characterized by mutation of COL1A1 (17q21.33) or COL1A2 (7q21.3) genes, that are involved in α-1 and α-2 chains of type 1 collagen synthesis. The clinical spectrum of this new clinical entity is broad: patients could present a mixed phenotype that includes features of both osteogenesis imperfecta (bone fragility, long bone fractures, blue sclerae, short stature) and Ehlers−Danlos syndrome (joint hyperextensibility, soft and hyperextensible skin, abnormal wound healing, easy bruising, vascular fragility). We reported the case of a young Caucasian girl with severe short stature and a previous history of neuroblastoma, who displayed the compound phenotype of OI/EDS. Next generation sequencing was applied to the proband and her parent genome. Our patient presented a de novo heterozygous COL1A1 variant (c.3235G>A, p.Gly1079Ser), whose presence might be indicative of diagnosis of OI/EDS overlap syndrome. We also hypothesize that the association with the previous history of neuroblastoma could be influenced by the presence of COL1A1 mutation, whose role has been already described in the behavior and progression of some cancers.

Standardizing genetic and metabolic consults for non-accidental trauma at a large pediatric academic center

BACKGROUND

Evaluations of suspected non-accidental trauma (NAT) often include consultation with genetic and metabolic teams to assess patients for rare genetic conditions that can mimic or exacerbate child abuse. Diagnoses that may be questioned during court proceedings include osteogenesis imperfecta (OI) and glutaric aciduria type 1 (GA1). Currently there are no official society guidelines for the genetic or metabolic workup of suspected NAT.

OBJECTIVE

To standardize consult recommendations for suspected NAT through collaboration between the Genetics and Genomics Division and the Child Protection Team (CPT).

PARTICIPANTS AND SETTINGS

Children evaluated for suspected NAT at a single pediatric referral center.

METHODS

A year of inpatient consult requests for suspected NAT to the genetics division were reviewed. The most common indications for consult were fractures and subdural hematoma. Consult recommendations for similar indications varied between providers. A standard operating procedure (SOP) with specific recommendations for suspected NAT consults for fractures, intracranial hemorrhage, and other indications was created based on expert reviews and other relevant literature. A questionnaire assessing division practice patterns for these consults was distributed both pre (n = 17) and post-introduction of the SOP (n = 11).

RESULTS

Adherence to the SOP and impact on suspected NAT consult recommendations were assessed at 18 months after SOP introduction. Consult recommendations were in line with the SOP for 7/11 consults pre-intervention and 6/7 consults post-intervention. Providers were more likely to report feeling extremely or very confident they were using evidence-based medicine for NAT consults post-intervention.

Current Overview of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI), or brittle bone disease, is a heterogeneous disorder characterised by bone fragility, multiple fractures, bone deformity, and short stature. OI is a heterogeneous disorder primarily caused by mutations in the genes involved in the production of type 1 collagen. Severe OI is perinatally lethal, while mild OI can sometimes not be recognised until adulthood. Severe or lethal OI can usually be diagnosed using antenatal ultrasound and confirmed by various imaging modalities and genetic testing. The combination of imaging parameters obtained by ultrasound, computed tomography (CT), and magnetic resource imaging (MRI) can not only detect OI accurately but also predict lethality before birth. Moreover, genetic testing, either noninvasive or invasive, can further confirm the diagnosis prenatally. Early and precise diagnoses provide parents with more time to decide on reproductive options. The currently available postnatal treatments for OI are not curative, and individuals with severe OI suffer multiple fractures and bone deformities throughout their lives. In utero mesenchymal stem cell transplantation has been drawing attention as a promising therapy for severe OI, and a clinical trial to assess the safety and efficacy of cell therapy is currently ongoing. In the future, early diagnosis followed by in utero stem cell transplantation should be adopted as a new therapeutic option for severe OI.

Genetic causes of fractures and subdural hematomas: fact versus fiction

Genetic disorders are in the differential diagnosis when young children present with unexplained fractures or intracranial hemorrhage. For medical and legal reasons, it is imperative to make the correct diagnosis and provide clear, evidence-based explanations of how alternative diagnoses were ruled out. A genetics consultation in cases of suspected child physical abuse should synthesize the history of present illness, medical history, family history, physical examination, and radiologic and laboratory findings in consultation with other specialists. The medical geneticist highlights how these disorders truly present. When the natural history of a genetic disorder is understood, it becomes clear that genetic disorders are not mysterious or difficult to diagnose. As highlighted in this case-based review, mainstream medical practice allows for differentiation among the intracranial and skeletal manifestations of osteogenesis imperfecta, Menkes disease, glutaric acidemia type 1 and child physical abuse. This review also highlights how a genetic disorder, Ehlers-Danlos syndrome, can be misused in a courtroom. Finally, this review summarizes when genetic testing is appropriate in cases of suspected child physical abuse.

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.

Genomic Diagnosis for Pediatric Disorders: Revolution and Evolution

Powerful, recent advances in technologies to analyze the genome have had a profound impact on the practice of medical genetics, both in the laboratory and in the clinic. Increasing utilization of genome-wide testing such as chromosomal microarray analysis and exome sequencing have lead a shift toward a "genotype-first" approach. Numerous techniques are now available to diagnose a particular syndrome or phenotype, and while traditional techniques remain efficient tools in certain situations, higher-throughput technologies have become the de facto laboratory tool for diagnosis of most conditions. However, selecting the right assay or technology is challenging, and the wrong choice may lead to prolonged time to diagnosis, or even a missed diagnosis. In this review, we will discuss current core technologies for the diagnosis of classic genetic disorders to shed light on the benefits and disadvantages of these strategies, including diagnostic efficiency, variant interpretation, and secondary findings. Finally, we review upcoming technologies posed to impart further changes in the field of genetic diagnostics as we move toward "genome-first" practice.

Reproductive options for families at risk of Osteogenesis Imperfecta: a review

Background

Osteogenesis Imperfecta (OI) is a rare genetic disorder involving bone fragility. OI patients typically suffer from numerous fractures, skeletal deformities, shortness of stature and hearing loss. The disorder is characterised by genetic and clinical heterogeneity. Pathogenic variants in more than 20 different genes can lead to OI, and phenotypes can range from mild to lethal forms. As a genetic disorder which undoubtedly affects quality of life, OI significantly alters the reproductive confidence of families at risk. The current review describes a selection of the latest reproductive approaches which may be suitable for prospective parents faced with a risk of OI. The aim of the review is to alleviate suffering in relation to family planning around OI, by enabling prospective parents to make informed and independent decisions.

Main body

The current review provides a comprehensive overview of possible reproductive options for people with OI and for unaffected carriers of OI pathogenic genetic variants. The review considers reproductive options across all phases of family planning, including pre-pregnancy, fertilisation, pregnancy, and post-pregnancy. Special attention is given to the more modern techniques of assisted reproduction, such as preconception carrier screening, preimplantation genetic testing for monogenic diseases and non-invasive prenatal testing. The review outlines the methodologies of the different reproductive approaches available to OI families and highlights their advantages and disadvantages. These are presented as a decision tree, which takes into account the autosomal dominant and autosomal recessive nature of the OI variants, and the OI-related risks of people without OI.

The complex process of decision-making around OI reproductive options is also discussed from an ethical perspective.

Conclusion

The rapid development of molecular techniques has led to the availability of a wide variety of reproductive options for prospective parents faced with a risk of OI. However, such options may raise ethical concerns in terms of methodologies, choice management and good clinical practice in reproductive care, which are yet to be fully addressed.

Methodological quality of clinical practice guidelines for genetic testing in children: A systematic assessment using the appraisal of guidelines for research and evaluation II instrument

Genetic testing of children is faced with numerous problems. High-quality clinical practice guidelines (CPGs) are needed to ensure its safe, and appropriate use. This study aimed to systematically identify the current CPGs for genetic testing in children, and to assess the methodological quality of these CPGs.We searched 6 databases, 3 guideline clearinghouses, and 9 web sites of relevant academic agencies from inception to February 2019. CPGs focused on genetic testing in children were included. Four reviewers independently appraised the quality of the eligible CPGs using the appraisal of guidelines for research, and evaluation (AGREE) II instrument.Seventeen CPGs meeting our inclusion criteria were included. Among them, 16 CPGs were focused on the genetic diagnosis/evaluation of diseases, while only 1 CPG was focused on pharmacogenetics. The median domain scores from highest to lowest were: scope and purpose 80.56% (range: 56.95%-87.50%), clarity of presentation 72.22% (range: 45.83%-88.89%), stakeholder involvement 45.83% (range: 27.78%-55.56%), applicability 31.25% (range: 19.79%-54.17%), rigor of development 21.88%, (range: 13.02%-71.88%), and editorial independence 18.75% (range: 0%-83.33%). According to the overall quality, 6 (35%) CPGs were "not recommended," 8 (47%) CPGs were "recommended with modifications," and only 3 (18%) CPGs were "recommended." The clinical topics of the "recommended" CPGs were warfarin, familial Mediterranean fever, and pediatric pulmonary arterial hypertension.The quality of CPGs for genetic testing in children was generally low, and variable across different CPGs and different AGREE II domains. In future guideline development, more attention should be paid to the aspects of stakeholder involvement, rigor of development, applicability, and editorial independence. Not only will guideline users benefit from our results when determining whether to adopt related CPGs to guide genetic testing in children, but guideline developers could also take into account our results to improve the quality of future CPGs.

A Unique Association of Osteogenesis Imperfecta with Bilateral Renal Osteodystrophy and Gastroenteritis in a Three-year-old Boy

We describe a three-year-old male child who presented to the pediatrics out-patient department with a history of decrease in appetite, generalized weakness, on and off loose motions for one year, inability to walk and sit for eight months with a loss of neck holding for 14 days. On examination, the patient had a classic frog-shaped leg posture. X-rays of chest, skull, pelvis and long bones were performed which showed osteopenic bones, frontal bossing and multiple microfractures, which were classic for osteogenesis Imperfecta but the child did not have other salient features such as blue sclera, otosclerosis, and respiratory difficulty. The patient also had urinary complaints due to which ultrasound of kidney ureters and bladder (KUB) was performed, which showed bilateral renal calculi and grade 2 renal parenchymal changes. This case report illustrates the evaluation of the child with osteogenesis imperfecta, as well as the unique association of renal osteodystrophy and gastroenteritis with it.

Genetic analysis of adults heterozygous for ALPL mutations

Hypophosphatasia (HPP) is a rare inherited metabolic bone disease due to a deficiency of the tissue nonspecific alkaline phosphatase isoenzyme (TNSALP) encoded by the ALPL gene. Patients have consistently low serum alkaline phosphatase (AP), so that this parameter is a good hallmark of the disease. Adult HPP is heterogeneous, and some patients present only mild nonpathognomonic symptoms which are also common in the general population such as joint pain, osteomalacia and osteopenia, chondrocalcinosis, arthropathy and musculoskeletal pain. Adult HPP may be recessively or dominantly inherited; the latter case is assumed to be due to the dominant negative effect (DNE) of missense mutations derived from the functional homodimeric structure of TNSALP. However, there is no biological argument excluding the possibility of other causes of dominant HPP. Rheumatologists and endocrinologists are increasingly solicited for patients with low AP and nonpathognomonic symptoms of HPP. Many of these patients are heterozygous for an ALPL mutation and a challenging question is to determine if these symptoms, which are also common in the general population, are attributable to their heterozygous ALPL mutation or not. In an attempt to address this question, we reviewed a cohort of 61 adult patients heterozygous for an ALPL mutation. Mutations were distinguished according to their statistical likelihood to show a DNE. One-half of the patients carried mutations predicted with no DNE and were slightly less severely affected by the age of onset, serum AP activity and history of fractures. We hypothesized that these mutations result in another mechanism of dominance or are recessive alleles. To identify other genetic factors that could trigger the disease phenotype in heterozygotes for potential recessive mutations, we examined the next-generation sequencing results of 32 of these patients for a panel of 12 genes involved in the differential diagnosis of HPP or candidate modifier genes of HPP. The heterozygous genotype G/C of the COL1A2 coding SNP rs42524 c.1645C > G (p.Pro549Ala) was associated with the severity of the phenotype in patients carrying mutations with a DNE whereas the homozygous genotype G/G was over-represented in patients carrying mutations without a DNE, suggesting a possible role of this variant in the disease phenotype. These preliminary results support COL1A2 as a modifier gene of HPP and suggest that a significant proportion of adult heterozygotes for ALPL mutations may have unspecific symptoms not attributable to their heterozygosity.

Hypophosphatasia

We review here clinical, pathophysiological, diagnostic, genetic and molecular aspects of Hypophosphatasia (HPP), a rare inherited metabolic disorder. The clinical presentation is a continuum ranging from a prenatal lethal form with no skeletal mineralization to a mild form with late adult onset presenting with nonpathognomonic symptoms. The prevalence of severe forms is low, whereas less severe forms are more frequently observed. The disease is caused by loss-of-function mutations in the ALPL gene encoding the Tissue Nonspecific Alkaline Phosphatase (TNSALP), a central regulator of mineralization. Severe forms are recessively inherited, whereas moderate forms are either recessively or dominantly inherited, and the more severe the disease is, the more often it is subject to recessive inheritance. The diagnosis is based on a constantly low alkaline phosphatase (AP) activity in serum and genetic testing that identifies ALPL mutations. More than 340 mutations have been identified and are responsible for the extraordinary clinical heterogeneity. A clear but imperfect genotype-phenotype correlation has been observed, suggesting that other genetic or environmental factors modulate the phenotype. Enzyme replacement therapy is now available for HPP, and other approaches, such as gene therapy, are currently being investigated.

Fracture Patterns Differ Between Osteogenesis Imperfecta and Routine Pediatric Fractures

BACKGROUND

It is important to estimate the likelihood that a pediatric fracture is caused by osteogenesis imperfecta (OI), especially the least severe type of OI (type 1).

METHODS

We reviewed records of 29,101 pediatric patients with fractures from 2003 through 2015. We included patients with closed fractures not resulting from motor vehicle accidents, gunshot wounds, nonaccidental trauma, or bone lesions. Patients with OI of any type were identified through International Classification of Diseases-9 code. We randomly sampled 500 pediatric patients in whom OI was not diagnosed to obtain a control (non-OI) group. We reviewed age at time of fracture, sex, fracture type, laterality, and bone and bone region fractured. Bisphosphonate use and OI type were documented for OI patients. Subanalysis of patients with type-1 OI was performed. The Fisher exact and χ tests were used to compare fracture rates between groups. P<0.05 was considered significant. Positive likelihood ratios for OI were calculated by fracture pattern.

RESULTS

The non-OI group consisted of 500 patients with 652 fractures. The OI group consisted of 52 patients with 209 fractures. Non-OI patients were older at the time of fracture (mean, 9.0±5.0 y) than OI patients (mean, 5.5±4.4 y) (P<0.001). OI patients had more oblique, transverse, diaphyseal, and bilateral long-bone fractures than non-OI patients (all P<0.001). Non-OI patients had more buckle (P=0.013), metaphyseal (P<0.001), and physeal (P<0.001) fractures than OI patients. For patients with type-1 OI and long-bone fractures (n=18), rates of transverse and buckle fractures were similar compared with controls. Transverse humerus (15.2), olecranon (13.8), and diaphyseal humerus (13.0) fractures had the highest positive likelihood ratios for OI, and physeal (0.09) and supracondylar humerus (0.1) fractures had the lowest.

CONCLUSIONS

Transverse and diaphyseal humerus and olecranon fractures were most likely to indicate OI. Physeal and supracondylar humerus fractures were least likely to indicate OI. Radiographic fracture pattern is useful for estimating likelihood of OI.

LEVEL OF EVIDENCE

Level III.

Efficacy of Bisphosphonates on Bone Mineral Density and Fracture Rate in Patients With Osteogenesis Imperfecta: A Systematic Review and Meta-analysis

Epidemiological evidence suggests that bisphosphonates are the most promising drugs for patients with osteogenesis imperfecta (OI). However, data on this issue are controversial. We conducted a meta-analysis to assess the efficacy of bisphosphonates on bone mineral density (BMD) and fracture rate in patients with OI. Electronic databases were searched to find relevant studies. Two reviewers independently identified relevant randomized controlled trials, which evaluated the efficacy of bisphosphonates in patients with OI. Outcome measures were fracture incidence and BMD changes in different skeletal sites. A total of 9 randomized controlled trials including 557 patients were identified. Meta-analysis demonstrated a beneficial effect of bisphosphonates on spine BMD Z-score and area BMD (in grams per square centimeter) %. Patients treated with bisphosphonates had a lower risk of fracture [risk ratio (RR) = 0.80; 95% confidence interval (CI): 0.66-0.97] compared with those in control groups. In children, bisphosphonates were efficacious in reducing fractures (RR = 0.80; 95% CI: 0.66-0.97), where in adults, bisphosphonates seemed equivalent to placebo in that respect (RR = 0.82; 95% CI: 0.42-1.59), although no significant difference was noted between these 2 RRs (test of interaction, z = -0.07; P = 0.94). There was also no significant difference in reducing fractures between oral and intravenous bisphosphonates (P = 0.23). This study showed that bisphosphonates could increase the BMD and reduce the risk of facture in patients with OI. There was no enough evidence to identify any differences in efficacy between oral and intravenous bisphosphonates on fracture reduction, as well as between children and adults.

Hypermobile Ehlers-Danlos syndrome (a.k.a. Ehlers-Danlos syndrome Type III and Ehlers-Danlos syndrome hypermobility type): Clinical description and natural history

The hypermobile type of Ehlers-Danlos syndrome (hEDS) is likely the most common hereditary disorder of connective tissue. It has been described largely in those with musculoskeletal complaints including joint hypermobility, joint subluxations/dislocations, as well as skin and soft tissue manifestations. Many patients report activity-related pain and some go on to have daily pain. Two undifferentiated syndromes have been used to describe these manifestations-joint hypermobility syndrome and hEDS. Both are clinical diagnoses in the absence of other causation. Current medical literature further complicates differentiation and describes multiple associated symptoms and disorders. The current EDS nosology combines these two entities into the hypermobile type of EDS. Herein, we review and summarize the literature as a better clinical description of this type of connective tissue disorder. © 2017 Wiley Periodicals, Inc.

Patient Perspectives on Intimate Partner Violence Discussion during Genetic Counseling Sessions

Intimate partner violence (IPV) is a major health concern in the United States (ACOG 2013). The World Health Organization (WHO) describes IPV as any physical, sexual, psychological harm by a current or former intimate partner (WHO 2016). Due to the psychosocial depth and nature of discussions within genetic counseling sessions, patients may disclose and/or discuss IPV as it relates to sexual well-being, reproductive and overall health. This study aims to assess the role for IPV screening, counseling and intervention in genetic counseling practice by investigating the incidence, experiences and attitudes about IPV among genetic counseling patients. Patients receiving genetic counseling at an urban metropolitan hospital were anonymously surveyed about experiences and perspectives on IPV as a topic of discussion during genetic counseling sessions. Among 60 eligible patients, 50 completed the survey (49 females, 1 male, of which, 5 identified as LGBT) ages 20 to 66. The incidence of IPV in this group was 16.0 % (n = 8). Majority of participants had never been asked about IPV by a healthcare provider (n = 32; 64.0%), would have felt comfortable answering questions about IPV by their healthcare provider (n = 34; 68.0%), and would have felt comfortable answering questions about IPV by their genetic counselor (n = 39; 78.0%). Perspectives from all participants, notably those with IPV history, provided insights to the role of genetic counselors in areas for IPV screening and counseling training.

Health outcomes of neonates with osteogenesis imperfecta: a cross-sectional study

OBJECTIVE

To assess at-birth health outcomes of neonates with osteogenesis imperfecta (OI).

STUDY DESIGN

A total of 53 women who self-reported having had at least one child with OI completed the survey. We evaluated pregnancy length, neonatal intensive care unit (NICU) usage, at-birth complications, and the child's clinical information including OI type, height and weight.

RESULTS

Information was gathered on a total of 77 children (60 type I, 4 type III and 13 type IV). Health conditions reported at birth included breech presentation (24%), prematurity (27%), fracture (18%), bone deformity (18%) and respiratory problems (22%). Approximately 31% (n = 24) received NICU care. There was a significant association between younger maternal age, preterm delivery and NICU admission.

CONCLUSION

Our findings suggest that newborns with OI appear to be at high risk of skeletal disorders, preterm delivery and breech presentation. Younger maternal age and preterm delivery seem to be strong predictors of the need for NICU care. Our data suggest that pregnant women with OI younger than 20 years of age may benefit from added clinical supervision in anticipation of adverse effects on their child.

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.

Cesarean delivery is not associated with decreased at-birth fracture rates in osteogenesis imperfecta

Purpose

Osteogenesis imperfecta (OI) predisposes to recurrent fractures. The moderate-to-severe forms of OI present with antenatal fractures and the mode of delivery that would be safest for the fetus is not known.

Methods

We conducted systematic analyses on the largest cohort of individuals (n=540) with OI enrolled to-date in the OI Linked Clinical Research Centers. Self-reported at-birth fracture rates were compared in individuals with OI types I, III, and IV. Multivariate analyses utilizing backward-elimination logistic regression model building were performed to assess the effect of multiple covariates including method of delivery on fracture-related outcomes.

Results

When accounting for other covariates, at-birth fracture rates did not differ based on whether delivery was by vaginal route or by cesarean section (CS). Increased birth weight conferred higher risk for fractures irrespective of the delivery method. In utero fracture, maternal history of OI, and breech presentation were strong predictors for choosing CS for delivery.

Conclusion

Our study, the largest to analyze the effect of various factors on at-birth fracture rates in OI shows that delivery by CS is not associated with decreased fracture rate. With the limitation that the fracture data were self-reported in this cohort, these results suggest that CS should be performed only for other maternal or fetal indications, but not for the sole purpose of fracture prevention in OI.

The evaluation of suspected child physical abuse

Child physical abuse is an important cause of pediatric morbidity and mortality and is associated with major physical and mental health problems that can extend into adulthood. Pediatricians are in a unique position to identify and prevent child abuse, and this clinical report provides guidance to the practitioner regarding indicators and evaluation of suspected physical abuse of children. The role of the physician may include identifying abused children with suspicious injuries who present for care, reporting suspected abuse to the child protection agency for investigation, supporting families who are affected by child abuse, coordinating with other professionals and community agencies to provide immediate and long-term treatment to victimized children, providing court testimony when necessary, providing preventive care and anticipatory guidance in the office, and advocating for policies and programs that support families and protect vulnerable children.

Forensic medical evaluations of child maltreatment: a proposed research agenda

Physicians play an important role in the forensic evaluation of suspected child abuse and neglect. There has been considerable progress in the medical field, helping distinguish findings related to maltreatment from other conditions or circumstances. Nevertheless, important questions remain. This article covers several of these questions and proposes a research agenda concerning five main topics: sexual abuse, neglect, fractures, abusive head trauma, and physicians work in interdisciplinary settings. The suggestions are hardly inclusive, but offer suggestions the authors think are priorities, and ones that research could reasonably address. By providing some background to gaps in our knowledge, this paper should be of interest to a broader audience than just medical professionals.

Advances in evaluating the fetal skeleton

In this review, we discuss aspects of the prenatal diagnosis of fetal skeletal malformations, concentrating on the advantages offered by different imaging techniques and the approaches that are of value in evaluating a suspected skeletal dysplasia. We also briefly address the findings in some of the commoner malformations of the fetal skeleton that may be encountered.

Osteogenesis imperfecta type I: A case report

A 15-year-old male patient was admitted to hospital having experienced repeated fractures over the previous three years, predominantly due to falling down or overexertion. The clinical signs and radiological features, such as recurrent fractures, blue sclera and low bone mineral density (BMD) level, all led to the diagnosis of a mild form of osteogenesis imperfecta (OI) type I. The patient began treatment with a regular intake of calcium (1,000 mg/day), an adequate intake of vitamin D (800 U/day) and intravenous pamidronate (60 mg). Following four months of treatment, the symptoms and quality of life of the patient improved. This patient appears to be a rare case of OI type I.

Complement component C3: Serologic signature for osteogenesis imperfecta. Analysis of a comparative proteomic study

BACKGROUND/PURPOSE

Osteogenesis imperfecta (OI) is a disease characterized by low bone mass and bony fragility. This study investigated the serum proteomic profiles and their correlation with bone density for OI cases.

METHODS

Twenty OI patients and 20 control participants were included. Comparative serum proteomic profiles were analyzed by two-dimensional electrophoresis and tandem mass spectrometry. Serum protein levels were measured by enzyme-linked immunosorbent assay. Cutoff values and areas under the curve were estimated by the receiver operating characteristic curve. Bone mineral density data was obtained from all OI patients.

RESULTS

Candidate proteins identified by electrophoresis were complement component C3 (C3), vitamin D-binding protein (DBP), and haptoglobin (HP). Enzyme-linked immunosorbent assay validation showed that OI patients had decreased C3 and DBP and increased HP. The results were not affected by age or bisphosphonate use. Serum C3 levels significantly correlated with bone mineral density of the lumbar spine and hip. C3 had the greatest areas under the curve to distinguish OI from healthy controls.

CONCLUSION

Serum C3, DBP, and HP are emerging serologic signatures for OI. Concentrations of serum C3 correlated with the T score of OI patients. C3 had the greatest areas under the curve of the three proteins to distinguish OI from healthy controls.

Osteogenesis imperfecta Type VI with severe bony deformities caused by novel compound heterozygous mutations in SERPINF1

Osteogenesis imperfecta (OI) comprises a heterogeneous group of disorders characterized by bone fragility, frequent fractures, and low bone mass. Dominantly inherited COL1A1 or COL1A2 mutations appear to be causative in the majority of OI types, but rare recessively inherited genes have also been reported. Recently, SERPINF1 has been reported as another causative gene in OI type VI. To date, only eight SERPINF1 mutations have been reported and all are homozygous. Our patient showed no abnormalities at birth, frequent fractures, osteopenia, and poor response on pamidronate therapy. At the time of her most recent evaluation, she was 8 yr old, and could not walk independently due to frequent lower-extremity fractures, resulting in severe deformity. No clinical signs were seen of hearing impairment, blue sclera, or dentinogenesis imperfecta. In this study, we describe the clinical and radiological findings of one Korean patient with novel compound heterozygous mutations (c.77dupC and c.421dupC) of SERPINF1.

Fractures at diagnosis in infants and children with osteogenesis imperfecta

BACKGROUND

In infants and children with fractures from an unclear cause, osteogenesis imperfecta (OI) is often included as a potential etiology. In infants and children with OI there exists a gap in the published literature regarding the fracture pattern seen at the time of diagnosis. As an additional aid to the diagnosis of OI, we sought to characterize the fracture patterns in infants and children at the time of their diagnosis.

METHODS

We performed a retrospective chart review of a series of infants and children under 18 years of age who have the diagnosis of OI (any type) from a single institution.

RESULTS

We identified 68 infants and children with OI: 23 (34%) type 1, 1 (2%) type 2, 17 (25%) type 3, 24 (35%) type 4, and 3 (4%) unknown type. A family history of OI was present in 46% of children. Forty-nine (72.0%) patients were diagnosed solely on clinical characteristics, without genetic or fibroblast confirmation. Rib fractures were noted in 21% of the subjects with none being identified during infancy. The number of fractures identified at diagnosis ranged from 1 to >37 with 7 (10%) having more than 2 fractures. All subjects with more than 2 fractures were diagnosed prenatally or in the immediate newborn period. Seventeen (25%) infants were diagnosed after 1 week of age but before 12 months of age. None of these infants had either rib fractures or more than 1 fracture at the time of diagnosis.

CONCLUSIONS

The majority of children diagnosed with OI are diagnosed by clinical features alone. The fracture pattern at the time of diagnosis in OI is variable with 10% having more than 2 fractures. The diagnosis of OI was made in utero or at delivery in 43% of children. Multiple rib fractures in an infant would be an unexpected finding in OI.

LEVEL OF EVIDENCE

Level III.

Osteogenesis imperfecta misdiagnosed as child abuse

The differential diagnosis of child abuse includes osteogenesis imperfecta (OI). Mild phenotypes of OI may be misdiagnosed as child abuse. The purpose of this study was to review the experience of families in which OI was misdiagnosed as child abuse. Sixty-one potential cases of misdiagnosis were identified from a lay support organization. Upon review of the medical records, 33 cases were identified with a confirmed diagnosis of OI (skin biopsy or DNA blood test). Questionnaires were given to families to describe their condition and experiences. There were 19 male and 14 female children. Mean age at presentation was 7.1 months (range: 1-23 months). All patients had fractures and the presenting symptoms included pain (n=14), swelling (n=7), decreased limb movement (n=5), or unusual limb position (n=2). Abnormal radiograph findings consistent with OI were found in 19 of 33 patients (58%), clinical findings of OI were present in 23 of 33 patients (70%), and a family history that could be supportive of OI was present in 18 of 33 families (55%). Children were removed from the family in 70% of cases and older siblings were removed from the family in 62% of cases. The mean age at the time of diagnosis of OI was 10.5 months (range: 3-35 months). The consequences of misdiagnosis of OI as child abuse are devastating to the family. OI should be considered in all cases of suspected child abuse. In children with any clinical, radiographic, or family history features of OI, early involvement of a bone specialist and performance of laboratory testing should be considered to establish a timely and accurate diagnosis.

EMQN best practice guidelines for the laboratory diagnosis of osteogenesis imperfecta

Osteogenesis imperfecta (OI) comprises a group of inherited disorders characterized by bone fragility and increased susceptibility to fractures. Historically, the laboratory confirmation of the diagnosis OI rested on cultured dermal fibroblasts to identify decreased or abnormal production of abnormal type I (pro)collagen molecules, measured by gel electrophoresis. With the discovery of COL1A1 and COL1A2 gene variants as a cause of OI, sequence analysis of these genes was added to the diagnostic process. Nowadays, OI is known to be genetically heterogeneous. About 90% of individuals with OI are heterozygous for causative variants in the COL1A1 and COL1A2 genes. The majority of remaining affected individuals have recessively inherited forms of OI with the causative variants in the more recently discovered genes CRTAP, FKBP10, LEPRE1,PLOD2, PPIB, SERPINF1, SERPINH1 and SP7, or in other yet undiscovered genes. These advances in the molecular genetic diagnosis of OI prompted us to develop new guidelines for molecular testing and reporting of results in which we take into account that testing is also used to ‘exclude' OI when there is suspicion of non-accidental injury. Diagnostic flow, methods and reporting scenarios were discussed during an international workshop with 17 clinicians and scientists from 11 countries and converged in these best practice guidelines for the laboratory diagnosis of OI.

Complete COL1A1 allele deletions in osteogenesis imperfecta

PURPOSE

To identify a molecular genetic cause in patients with a clinical diagnosis of osteogenesis imperfecta (OI) type I/IV.

METHODS

The authors performed multiplex ligation-dependent probe amplification analysis of the COL1A1 gene in a group of 106 index patients.

RESULTS

In four families with mild osteogenesis imperfecta and no other phenotypic abnormalities, a deletion of the complete COL1A1 gene on one allele was detected, a molecular finding that to our knowledge has not been described before, apart from a larger chromosomal deletion detected by fluorescent in situ hybridization encompassing the COL1A1 gene in a patient with mild osteogenesis imperfecta and other phenotypic abnormalities. Microarray analysis in three of the four families showed that it did not concern a founder mutation.

CONCLUSION

The clinical picture of complete COL1A1 allele deletions is a comparatively mild type of osteogenesis imperfecta. As such, multiplex ligation-dependent probe amplification analysis of the COL1A1 gene is a useful additional approach to defining the mutation in cases of suspected osteogenesis imperfecta type I with no detectable mutation.

Current and emerging treatments for the management of osteogenesis imperfecta

Osteogenesis imperfecta (OI) is the most common bone genetic disorder and it is characterized by bone brittleness and various degrees of growth disorder. Clinical severity varies widely; nowadays eight types are distinguished and two new forms have been recently described although not yet classified. The approach to such a variable and heterogeneous disease should be global and therefore multidisciplinary. For simplicity, the objectives of treatment can be reduced to three typical situations: the lethal perinatal form (type II), in which the problem is survival at birth; the severe and moderate forms (types III-IX), in which the objective is 'autonomy'; and the mild form (type I), in which the aim is to reach 'normal life'. Three types of treatment are available: non-surgical management (physical therapy, rehabilitation, bracing and splinting), surgical management (intramedullary rod positioning, spinal and basilar impression surgery) and medical-pharmacological management (drugs to increase the strength of bone and decrease the number of fractures as bisphosphonates or growth hormone, depending on the type of OI). Suggestions and guidelines for a therapeutic approach are indicated and updated with the most recent findings in OI diagnosis and treatment.

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.

Looking past the lump: genetic aspects of inguinal hernia in children

Inguinal hernia is associated with a multitude of genetic syndromes. Disorders of the microfibril, elastin, collagen, and the glycosaminoglycan component of the extracellular matrix can result in an increase in the likelihood of inguinal hernia. In addition, inguinal hernia may be the presenting feature of disorders of sexual differentiation. Inguinal hernia of unknown etiology also occurs more commonly in several other groups of genetic diseases including chromosomal disorders, microdeletion disorders such as 22q11.2 microdeletion, and in single gene disorders. We review the genetics of connective tissue formation and focus on a series of genetic conditions that may present with or are characterized by a higher risk of inguinal hernia. A comprehensive review of the literature aims to provide a diagnostic framework to aid in the identification of patients with inguinal hernia as part of underlying genetic disease.

Fetal skeletal dysplasia: an approach to diagnosis with illustrative cases

Skeletal dysplasias are a heterogeneous group of conditions associated with various abnormalities of the skeleton. These conditions are caused by widespread disturbance of bone growth, beginning during the early stages of fetal development and evolving throughout life. Despite recent advances in imaging, fetal skeletal dysplasias are difficult to diagnose in utero due to a number of factors, including the large number of skeletal dysplasias and their phenotypic variability with overlapping features, lack of precise molecular diagnosis for many disorders, lack of a systematic approach, the inability of ultrasonography (US) to provide an integrated view, and variability in the time at which findings manifest in some skeletal dysplasias. US of suspected skeletal dysplasia involves systematic imaging of the long bones, thorax, hands and feet, skull, spine, and pelvis. Assessment of the fetus with three-dimensional US has been shown to improve diagnostic accuracy, since additional phenotypic features not detectable at two-dimensional US may be identified. The radiologist plays a major role in making an accurate diagnosis; however, representatives of other disciplines, including clinicians, molecular biologists, and pathologists, can also provide important diagnostic information.

Osteogenesis Imperfecta: update on presentation and management

Osteogenesis Imperfecta (OI) is a rare heritable condition characterized by bone fragility and reduced bone mass. Traditionally OI was classified into OI types I to IV and thought to be only due to a defect in the collagen gene, however through the discovery of the new types of OI-V to VII, breakthroughs have been made in understanding the pathophysiology of autosomal recessive OI and new genetic mutations, such as in CRTAP and P3H1 genes. OI can present at any age and be difficult to diagnose because of the wide phenotypic variation. Awareness of the new forms of OI, the differential diagnosis and the limitations of diagnostic tools, all help to correctly diagnose and manage a patient with OI. Cyclical intravenous pamidronate is now the standard of care for moderately to severely affected children with OI, given in combination with good orthopedic, physiotherapy and rehabilitation programs. The benefits and short term safety of cyclic bisphosphonates have been amply reported in the literature; however their long term effects are still under investigation. Newer more potent forms of bisphosphonates such as zoledronic acid have undergone and are still being subject to international multicentric drug trials and are beginning to replace pamidronate in some centers.