Prenatal diagnosis and management of intrauterine fracture

Reviewing hereditary connective tissue disorders: Proposals of harmonic medicolegal assessments

Hereditary connective tissue disorders (HCTDs) are a heterogeneous group of inherited diseases. These disorders show genetic mutations with loss of function of primary components of connective tissue, such as collagen and elastic fibers. There are more than 200 conditions that involve hereditary connective tissue disorders, while the most known are Marfan syndrome, Osteogenesis Imperfecta, and Ehlers-Danlos syndromes. These disorders need continuous updates, multidisciplinary skills, and specific methodologic evaluations sharing many medicolegal issues. Marfan syndrome and Ehlers-Danlos syndromes show a high risk of early sudden death. As a consequence of this, postmortem genetic testing can identify novel genotype-phenotype correlations which help the clinicians to assess personalized cardiovascular screening programs among the ill subjects. Genetic testing is also essential to identify children suffering from Osteogenesis Imperfecta, especially when a physical abuse is clinically suspected. However, this is a well-known clinical problem even though there are still challenges to interpret genetic data and variants of unknown significance due to the current extensive use of new genetic/genomic techniques. Additionally, the more significant applications and complexities of genomic testing raise novel responsibilities on the clinicians, geneticists, and forensic practitioners as well, increasing potential liability and medical malpractice claims. This systematic review provides a detailed overview on how multidisciplinary skills belonging to clinicians, medicolegal consultants, radiologists, and geneticists can cooperate to manage HCTDs from autopsy or clinical findings to genetic testing. Thus, technical aspects need to be addressed to the medicolegal community since there is no consensus works or guidelines which specifically discuss these issues.

Investigating the role of ASCC1 in the causation of bone fragility

Bi-allelic variants in ASCC1 cause the ultrarare bone fragility disorder "spinal muscular atrophy with congenital bone fractures-2" (SMABF2). However, the mechanism by which ASCC1 dysfunction leads to this musculoskeletal condition and the nature of the associated bone defect are poorly understood. By exome sequencing, we identified a novel homozygous deletion in ASCC1 in a female infant. She was born with severe muscular hypotonia, inability to breathe and swallow, and virtual absence of spontaneous movements; showed progressive brain atrophy, gracile long bones, very slender ribs, and a femur fracture; and died from respiratory failure aged 3 months. A transiliac bone sample taken postmortem revealed a distinct microstructural bone phenotype with low trabecular bone volume, low bone remodeling, disordered collagen organization, and an abnormally high bone marrow adiposity. Proteomics, RNA sequencing, and qPCR in patient-derived skin fibroblasts confirmed that ASCC1 was hardly expressed on protein and RNA levels compared with healthy controls. Furthermore, we demonstrate that mutated ASCC1 is associated with a downregulation of RUNX2, the master regulator of osteoblastogenesis, and SERPINF1, which is involved in osteoblast and adipocyte differentiation. It also exerts an inhibitory effect on TGF-β/SMAD signaling, which is important for bone development. Additionally, knockdown of ASCC1 in human mesenchymal stromal cells (hMSCs) suppressed their differentiation capacity into osteoblasts while increasing their differentiation into adipocytes. This resulted in reduced mineralization and elevated formation of lipid droplets. These findings shed light onto the pathophysiologic mechanisms underlying SMABF2 and assign a new biological role to ASCC1 acting as an important pro-osteoblastogenic and anti-adipogenic regulator.

Congenital absence of the skin: a case series report

Background

Extracranial congenital skin defects, defined as aplasia cutis congenita (ACC), are a rare clinical entity. The form of presentation varies among patients according to the causal agent and the point during pregnancy at which the defect occurs. We present a series of cases of noncranial ACC, analysing its possible etiopathogenesis and the evolution of the lesions.

Materials and methods

This is a retrospective review of cases of extracranial ACC at a tertiary hospital.

Case presentation

Patient 1 is a full-term newborn of a monochorionic diamniotic gestation with the death of one foetus at 14 weeks of gestational age. Physical examination revealed two skin defects located on the posterior aspect of both thoraco-abdominal flanks. Patient 2 is a full-term newborn presenting with an ulcer on the nasal tip and cephalic extension on a follow-up pregnancy ultrasound. Patient 3 is a full-term newborn of a monochorionic diamniotic gestation with twin feticide due to encephalocele, presenting an ulcer on the lateral aspect of the proximal third of her right leg. The gestation associates severe oligohydramnios due to premature rupture of the membranes and breech presentation. Patient 4 is a full-term newborn with an ulcer on the left antecubital fossa with no relevant gestational history.

Conclusion

The analysis of the obstetric history and the clinical presentation of the lesions helps to guide the aetiopathogenic diagnosis of congenital skin defects. The increased intracompartment pressure in the limbs is related to the increased severity of skin lesions and musculoskeletal and nerve involvement. Conservative treatment is related to a good prognosis for the lesions.

[Depressed skull fractures in newborns. Case report of ping-pong fracture and literature review]

Depressed skull fractures (ping-pong) in the fetus and newborn are associated with birth canal pathology, maternal trauma and birth trauma following instrumental delivery. The authors report a newborn with a depressed skull fracture (ping-pong) who underwent minimally invasive neurosurgical lifting of bone fragment through a burr hole. Strategy and methods of treatment of similar depressed skull fractures were comprehensively discussed. Moreover, the authors proposed a brief algorithm for the use of vacuum systems and various surgical techniques, including follow-up depending on type, cause, size of the fracture and concomitant intracranial lesions.

Fetal Fractures in an Infant with Maternal Ehlers-Danlos Syndrome, CCDC134 Pathogenic Mutation and a Negative Genetic Test for Osteogenesis Imperfecta

Intrauterine fractures are a rare clinical finding caused by abnormal early-life osteogenesis. In this case report, we reported a male infant with twenty-three intrauterine/fetal fractures resembling osteogenesis imperfecta and tested negative for COL1A1 and COL1A2 mutations. The infant’s mother had Ehlers–Danlos syndrome, hypermobility type. Whole-genome sequencing revealed that there were no pathologic mutations previously documented to be associated with intrauterine fracture. Genetic mutations reported to be associated with fragility fractures were identified. These include the pathogenic homozygous mutation in the CCDC134 gene. Other genetic variants that might be responsible for variable expressivity of the skeletal manifestation include the homozygous variants of the genes CCDC134, COL15A1 and ZFPM1, and the heterozygous variants of the genes MYH3, BCHE, AUTS2. This is the first reported case of in utero fractures, that was confirmed by X-ray after birth, in an infant who had no genetic evidence for osteogenesis imperfecta, had a homozygous pathogenic mutation of an osteogenesis gene and whose mother had Ehlers-Danlos syndrome hypermobility type. Therefore, we have identified a new genetic cause for in utero fractures. If after birth, this infant were found to have these fractures in various stages of healing with a negative genetic test for osteogenesis imperfecta he would have been misdiagnosed as due to nonaccidental trauma.

Malunion of an In Utero Metacarpal Fracture in a Standardbred Mare Presenting for Dystocia

In utero fracture and malunion of long bones is a rare condition in horses. Most foals with in utero fractures are aborted, and the identification of a fetal in utero fracture in a mare with dystocia has not been reported. A 7-year-old multiparous Standardbred mare presented to a referral center for correction of dystocia. Assisted vaginal delivery and controlled vaginal delivery attempts were unsuccessful mainly because of contracted tendons impeding mutation. As the foal was alive, a cesarean section was elected. The foal was delivered but ultimately euthanized because of the congenital abnormalities. Computed tomography of the right forelimb of the foal along with gross examination and histologic evaluation of the right metacarpus revealed the malunion of a previous in utero fracture. While a few cases have been reported of in utero fracture, many of these were in abortuses and not in fetuses at term, making this case a new presentation and potential etiology for dystocia.

Supraglottic Airway Rescue After Failed Fiberoptic Intubation in a Patient With Osteogenesis Imperfecta: A Case Report

We describe the management of a pregnant patient with osteogenesis imperfecta with a history of numerous fractures, severe scoliosis, and anticipated difficult airway. Her pregnancy was complicated by progressive shortness of breath and a fetal diagnosis of osteogenesis imperfecta. Spine anatomy precluded neuraxial anesthesia. Cesarean delivery was performed under general anesthesia at 34 weeks. Immediately after awake fiberoptic intubation and induction of general anesthesia, capnography waveform was lost with rapid profound oxygen desaturation. A supraglottic airway device was placed, oxygenation maintained with supraglottic airway and positive pressure ventilation throughout case, and the baby was delivered with Apgars of 8 and 9.

Spontaneous fetal femoral fracture: a case report and literature review

Spontaneous fetal femoral fractures are uncommon in the paediatric setting. The major clinical presentations of a spontaneous fetal femoral fracture are femoral angulation, shortness of the femur and even a marked fracture line. This case report describes a spontaneous fetal femoral fracture of the right femur, which was detected by routine ultrasonography during the 19^th week of gestation in a 24-year-old woman. On routine follow-up visits, the angulation of the right femur in the fetus gradually improved. A caesarean section was undertaken at 39 weeks +5 days of gestation and an X-ray was taken on the second day after birth, which showed that the fracture had healed and the callus had been absorbed. The lengths of the two femurs of the baby were not equal; the right femur was 84 mm, which was 11 mm shorter than the left femur. In cases like this, postnatal follow-up is essential so that an operation can be carried out in a timely manner when the deformity is apparent.

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.

Mutations in Subunits of the Activating Signal Cointegrator 1 Complex Are Associated with Prenatal Spinal Muscular Atrophy and Congenital Bone Fractures

Transcriptional signal cointegrators associate with transcription factors or nuclear receptors and coregulate tissue-specific gene transcription. We report on recessive loss-of-function mutations in two genes (TRIP4 and ASCC1) that encode subunits of the nuclear activating signal cointegrator 1 (ASC-1) complex. We used autozygosity mapping and whole-exome sequencing to search for pathogenic mutations in four families. Affected individuals presented with prenatal-onset spinal muscular atrophy (SMA), multiple congenital contractures (arthrogryposis multiplex congenita), respiratory distress, and congenital bone fractures. We identified homozygous and compound-heterozygous nonsense and frameshift TRIP4 and ASCC1 mutations that led to a truncation or the entire absence of the respective proteins and cosegregated with the disease phenotype. Trip4 and Ascc1 have identical expression patterns in 17.5-day-old mouse embryos with high expression levels in the spinal cord, brain, paraspinal ganglia, thyroid, and submandibular glands. Antisense morpholino-mediated knockdown of either trip4 or ascc1 in zebrafish disrupted the highly patterned and coordinated process of α-motoneuron outgrowth and formation of myotomes and neuromuscular junctions and led to a swimming defect in the larvae. Immunoprecipitation of the ASC-1 complex consistently copurified cysteine and glycine rich protein 1 (CSRP1), a transcriptional cofactor, which is known to be involved in spinal cord regeneration upon injury in adult zebrafish. ASCC1 mutant fibroblasts downregulated genes associated with neurogenesis, neuronal migration, and pathfinding (SERPINF1, DAB1, SEMA3D, SEMA3A), as well as with bone development (TNFRSF11B, RASSF2, STC1). Our findings indicate that the dysfunction of a transcriptional coactivator complex can result in a clinical syndrome affecting the neuromuscular system.

Prenatal diagnosis of musculoskeletal conditions

Ultrasonography is a safe, cost-effective tool used to prenatally detect common musculoskeletal conditions, including clubfoot, skeletal dysplasias, limb-length discrepancies, spinal abnormalities, and hand and other upper extremity deformities. With increased detection of such abnormalities, prenatal parental counseling by orthopaedic surgeons is being requested more frequently. Counseling is important for family education on prognosis and treatment options. A thorough understanding of the common musculoskeletal conditions diagnosed on prenatal ultrasonography, classification of these conditions, and the correlations of these classifications to postnatal severity allows the orthopaedic surgeon to conduct well-informed counseling sessions with families. Accurate information and counseling aids parents in understanding their child's diagnosis, assists clinicians in planning treatment algorithms, and optimizes family preparedness.

Blunt abdominal trauma to a pregnant woman resulting in a child with hemiplegic spastic cerebral palsy and permanent eye damage

Background

In today's life trauma is a common and important complication of pregnancy and remains one of the major contributors to maternal and fetal morbidity and mortality.

Case presentation

The authors reported a case of 4 years old child with hemiplegic spastic cerebral palsy and permanent left eye damage due to antenatal trauma. He was an off spring to a 33 years old woman gravida 6 para 5 from western Sudan, who sustained a domestic blunt abdominal trauma during her routine daily activities. The abdominal trauma occurred during the third trimester at 36^th week gestation of the pregnancy when the mother hit herself by the woody part of an axe non intentionally.

Conclusions

The findings from this case conclude that relatively minor trauma can have significant adverse effects on the fetus and can be devastating.

Advances in the orthopedic management of osteogenesis imperfecta

The long-established study of osteogenesis imperfecta (OI) has opened a realm of scientific research surrounding connective tissue disorders. Over the past decade alone there have been vast advancements in the understanding of the underlying genetic variations of this disease, pharmacologic treatments, and the technological and surgical options for fracture deformity. It is important to appreciate the progressive nature of the advances concerning OI. This article aims to synthesize the expanding evolution of the field surrounding OI over the past decade.

Osteogenesis Imperfecta: A Review with Clinical Examples

Osteogenesis imperfecta (OI) is characterized by susceptibility to bone fractures, with a severity ranging from subtle increase in fracture frequency to prenatal fractures. The first scientific description of OI dates from 1788. Since then, important milestones in OI research and treatment have, among others, been the classification of OI into 4 types (the 'Sillence classification'), the discovery of defects in collagen type I biosynthesis as a cause of most cases of OI and the use of bisphosphonate therapy. Furthermore, in the past 5 years, it has become clear that OI comprises a group of heterogeneous disorders, with an estimated 90% of cases due to a causative variant in the COL1A1 or COL1A2 genes and with the remaining 10% due to causative recessive variants in the 8 genes known so far, or in other currently unknown genes. This review aims to highlight the current knowledge around the history, epidemiology, pathogenesis, clinical/radiological features, management, and future prospects of OI. The text will be illustrated with clinical descriptions, including radiographs and, where possible, photographs of patients with OI.

Identification and molecular characterization of two novel mutations in COL1A2 in two Chinese families with osteogenesis imperfecta

Osteogenesis imperfecta (OI, also known as brittle bone disease) is caused mostly by mutations in two type I collagen genes, COL1A1 and COL1A2 encoding the pro-α1 (I) and pro-α2 (I) chains of type I collagen, respectively. Two Chinese families with autosomal dominant OI were identified and characterized. Linkage analysis revealed linkage of both families to COL1A2 on chromosome 7q21.3-q22.1. Mutational analysis was carried out using direct DNA sequence analysis. Two novel missense mutations, c.3350A>G and c.3305G>C, were identified in exon 49 of COL1A2 in the two families, respectively. The c.3305G>C mutation resulted in substitution of a glycine residue (G) by an alanine residue (A) at codon 1102 (p.G1102A), which was found to be mutated into serine (S), argine (R), aspartic acid (D), or valine (V) in other families. The c.3350A>G variant may be a de novo mutation resulting in p.Y1117C. Both mutations co-segregated with OI in respective families, and were not found in 100 normal controls. The G1102 and Y1117 residues were evolutionarily highly conserved from zebrafish to humans. Mutational analysis did not identify any mutation in the COX-2 gene (a modifier gene of OI). This study identifies two novel mutations p.G1102A and p.Y1117C that cause OI, significantly expands the spectrum of COL1A2 mutations causing OI, and has a significant implication in prenatal diagnosis of OI.

Severe osteogenesis imperfecta: case report

The authors present a case of Osteogenesis Imperfecta, emphasizing the clinical and epidemiological characteristics, forms of classification and treatment of the disease. This is an important case not only to the knowledge of pediatricians and orthopedists, but also for other professionals involved with the problem. This article has been jointly described by the Departments of Pediatrics and Neonatology of the Girassol Clinic in Luanda Capital of the Republic of Angola, Africa.