Osteopathia striata with cranial sclerosis: clinical, radiological, and bone histological findings in an adolescent girl

Macrocephaly and Finger Changes: A Narrative Review

Macrocephaly, characterized by an abnormally large head circumference, often co-occurs with distinctive finger changes, presenting a diagnostic challenge for clinicians. This review aims to provide a current synthetic overview of the main acquired and genetic etiologies associated with macrocephaly and finger changes. The genetic cause encompasses several categories of diseases, including bone marrow expansion disorders, skeletal dysplasias, ciliopathies, inherited metabolic diseases, RASopathies, and overgrowth syndromes. Furthermore, autoimmune and autoinflammatory diseases are also explored for their potential involvement in macrocephaly and finger changes. The intricate genetic mechanisms involved in the formation of cranial bones and extremities are multifaceted. An excess in growth may stem from disruptions in the intricate interplays among the genetic, epigenetic, and hormonal factors that regulate human growth. Understanding the underlying cellular and molecular mechanisms is important for elucidating the developmental pathways and biological processes that contribute to the observed clinical phenotypes. The review provides a practical approach to delineate causes of macrocephaly and finger changes, facilitate differential diagnosis and guide for the appropriate etiological framework. Early recognition contributes to timely intervention and improved outcomes for affected individuals.

Osteopathia striata with cranial sclerosis causing a compressive optic neuropathy

BACKGROUND

Osteopathia striata combined with cranial sclerosis (OS-CS) is an inherited skeletal dysplasia that manifests with macrocephaly, orofacial abnormalities, thickened craniofacial bones, and vertically oriented radiodensities of the long bones.

CASE REPORT

Here, we present a severe case of OS-CS in a 4-year-old girl causing optic neuropathy as shown by radiographic evidence, ophthalmic findings, and histopathology. Previous genetic testing in this patient revealed a de novo heterozygous mutation in AMER1 (c.1057C>T, p.Arg353Ter). Although the patient had a pre-existing, appropriately functioning, ventriculoperitoneal (VP) shunt, a subsequent MRI of the brain and orbits showed narrowing of the bilateral optic nerve canals secondary to osseous thickening causing bilateral optic nerve atrophy, worse on the left. The patient underwent staged bilateral orbital osteotomies, optic canal decompression, and bilateral frontal craniotomy, and at 11 months postoperatively, her vision remained stable. Conclusions: While up to 50% of the patients with OS-CS may experience hearing loss due to cranial nerve compression, we present a case of severe visual loss secondary to OS-CS-associated optic nerve compression.

AXIN1 bi-allelic variants disrupting the C-terminal DIX domain cause craniometadiaphyseal osteosclerosis with hip dysplasia

Sclerosing skeletal dysplasias result from an imbalance between bone formation and resorption. We identified three homozygous, C-terminally truncating AXIN1 variants in seven individuals from four families affected by macrocephaly, cranial hyperostosis, and vertebral endplate sclerosis. Other frequent findings included hip dysplasia, heart malformations, variable developmental delay, and hematological anomalies. In line with AXIN1 being a central component of the β-catenin destruction complex, analyses of primary and genome-edited cells harboring the truncating variants revealed enhanced basal canonical Wnt pathway activity. All three AXIN1-truncating variants resulted in reduced protein levels and impaired AXIN1 polymerization mediated by its C-terminal DIX domain but partially retained Wnt-inhibitory function upon overexpression. Addition of a tankyrase inhibitor attenuated Wnt overactivity in the AXIN1-mutant model systems. Our data suggest that AXIN1 coordinates the action of osteoblasts and osteoclasts and that tankyrase inhibitors can attenuate the effects of AXIN1 hypomorphic variants.

Hereditary Metabolic Bone Diseases: A Review of Pathogenesis, Diagnosis and Management

Hereditary metabolic bone diseases are characterized by genetic abnormalities in skeletal homeostasis and encompass one of the most diverse groups among rare diseases. In this review, we examine 25 selected hereditary metabolic bone diseases and recognized genetic variations of 78 genes that represent each of the three groups, including sclerosing bone disorders, disorders of defective bone mineralization and disorder of bone matrix and cartilage formation. We also review pathophysiology, manifestation and treatment for each disease. Advances in molecular genetics and basic sciences has led to accurate genetic diagnosis and novel effective therapeutic strategies for some diseases. For other diseases, the genetic basis and pathophysiology remain unclear. Further researches are therefore crucial to innovate ways to overcome diagnostic challenges and develop effective treatment options for these orphan diseases.

Osteopathia striata in the mandible with cranial sclerosis: a case report and review of the literature

Osteopathia striata with cranial sclerosis (OS-CS) is a bone dysplasia characterized by a linear striated pattern of sclerosis, especially in the long bones, and cranial sclerosis. It has variable clinical findings but distinctive radiological findings. Multiple oral and dental findings have been associated with this disease and can be seen during dental and/or medical imaging of the head and neck. Dentists and clinicians must be familiar with these signs to differentiate them from pathosis or erroneous radiographs. In the following case, we present a patient with OS-CS that presented at The University of Florida College of Dentistry with multiple craniofacial manifestations of this syndrome that were seen on a panoramic radiograph, which is one of the most commonly requested radiographs by dentists.

Osteopathia Striata with Cranial Sclerosis: A Face-to-Radiograph-to-Gene Diagnosis

Osteopathia striata with cranial sclerosis is an X-linked dominant bone dysplasia with osteosclerosis. It should be suspected in girls with macrocephaly, intellectual disability with unique facial dysmorphic features. We described the clinical and radiological profile of a patient with this rare disorder. A novel heterozygous variant was identified in the AMER1 gene which leads to premature truncation of the AMER1 protein. Facial gestalt recognition using artificial intelligence and radiographic features were used to narrow the differential diagnosis.

Sclerosing bone dysplasias

The group of sclerosing bone dysplasia's is a clinically and genetically heterogeneous group of rare bone disorders which, according to the latest Nosology and classification of genetic skeletal disorders (2015), can be subdivided in three subgroups; the neonatal osteosclerotic dysplasias, the osteopetroses and related disorders and the other sclerosing bone disorders. Here, we give an overview of the most important radiographic and clinical symptoms, the underlying genetic defect and potential treatment options of the different sclerosing dysplasias included in these subgroups.

Human Genetics of Sclerosing Bone Disorders

PURPOSE OF REVIEW

The group of sclerosing bone disorders encompasses a variety of disorders all marked by increased bone mass. In this review, we give an overview of the genetic causes of this heterogeneous group of disorders and briefly touch upon the value of these findings for the development of novel therapeutic agents.

RECENT FINDINGS

Advances in the next-generation sequencing technologies are accelerating the molecular dissection of the pathogenic mechanisms underlying skeletal dysplasias. Throughout the years, the genetic cause of these disorders has been extensively studied which resulted in the identification of a variety of disease-causing genes and pathways that are involved in bone formation by osteoblasts, bone resorption by osteoclasts, or both processes. Due to this rapidly increasing knowledge, the insights into the regulatory mechanisms of bone metabolism are continuously improving resulting in the identification of novel therapeutic targets for disorders with reduced bone mass and increased bone fragility.

Germline mosaicism in osteopathia striata with cranial sclerosis--recurrence in siblings

We report recurrence of osteopathia striata with cranial sclerosis (OSCS) in two full siblings conceived by unaffected parents. Molecular confirmation of OSCS in both siblings was achieved by identification of a novel heterozygous mutation in the WTX gene. Neither parent had clinical features of OSCS nor was the pathogenic mutation demonstrable in DNA extracted from both peripheral blood leucocytes and buccal cells. This case demonstrates germline mosaicism in OSCS and represents the third report of mosaicism affecting the germline in families with OSCS. Previous reports were of parental gonadosomal mosaicism, with one showing recurrence in multiple children. Our observation adds to a body of evidence that suggests that germline mosaicism in OSCS may occur more frequently than believed previously and may have implications for counselling families with OSCS.

Osteopathia striata with cranial sclerosis (OSCS): review of the literature and case report demonstrating challenges of spinal fusion after trauma

Osteopathia striata with cranial sclerosis (OSCS) is a rare but well-described pathology characterized by abnormalities in bone deposition in the axial and cranial skeleton as well as other abnormalities and associated deficits. These skeletal abnormalities can lead to significant intra-operative challenges for the surgeon and influence outcomes for the patient. In this report, we present a case of a patient with OSCS who was involved in a traumatic motor vehicle crash and underwent posterior cervico-thoracic fusion for a T4 chance fracture. Bony abnormalities in the cervico-thoracic spine presented a significant operative challenge due to alterations in bony anatomy and bone architecture. This case serves as an example of the challenges that the spine surgeon faces when dealing with OSCS, and highlights the differences between OSCS and commoner skeletal hyperplasias such as osteopetrosis.

Osteomyelitis in an Osteopathia Striata with Cranial Sclerosis Patient

Osteopathia striata with cranial sclerosis (OS-CS) is characterized by linear bone dysplasia at the long bone radiographically and sclerotic change at the cranium. The purpose of this case report is to study the symptoms and treatments of osteomyelitis in a patient with OS-CS. A 41-year-old patient had pus discharge from a fistula at the mental region and increase in radiolucencies with sequestra in panoramic radiograph images. Computed tomography (CT) as well as radiograph images for the whole skeleton were taken. The patient was diagnosed with OS-CS. Sequestrectomy and fistulectomy were performed. The patient recovered and no relapse occurred within six months after surgery. For diagnosis of OS-CS, CT and additional radiograph images for the whole skeleton are required. Because of the increased bone density, this patient is prone to relapse after sequestrectomy. Therefore, the surgeon must minimize trauma with the least incision and exfoliation, and preoperative antibiotics.

Osteopathia striata with cranial sclerosis, Wilms’ tumor and the WTX gene

Osteopathia striata with cranial sclerosis (OSCS, OMIM#300373) is an X-linked dominant sclerosing bone dysplasia that shows a distinct phenotype in females and males. In 2009, Zandra Jenkins et al found that germline mutations in the FAM123B/WTX/AMER1 gene, mapped to chromosome Xq11.2, cause both the familial and sporadic forms of OSCS. Intriguingly, the WTX gene was already known as a putative tumor suppressor gene, since in 2007 Rivera et al had reported inactivating WTX mutations in Wilms’ tumor (WT), the most frequent renal tumor of childhood. Here we review the heterogeneous clinical presentation of OSCS patients and the involvement of WTX anomalies in OSCS and in WT.

Sclerosing bone dysplasias with involvement of the craniofacial skeleton

In this review we provide a complete overview of the existing sclerosing bone dysplasias with craniofacial involvement. Clinical presentation, disease course, the craniofacial symptoms, genetic transmission pattern and pathophysiology are discussed. There is an emphasis on radiologic features with a large collection of CT and MRI images. In previous reviews the craniofacial area of the sclerosing bone dysplasias was underexposed. However, craniofacial symptoms are often the first symptoms to address a physician. The embryology of the skull and skull base is explained and illustrated for a better understanding of the affected areas.

The male phenotype in osteopathia striata congenita with cranial sclerosis

Osteopathia striata with cranial sclerosis (OSCS) is an X-linked disease caused by truncating mutations in WTX. Females exhibit sclerotic striations on the long bones, cranial sclerosis, and craniofacial dysmorphism. Males with OSCS have significant skeletal sclerosis, do not have striations but do display a more severe phenotype commonly associated with gross structural malformations, patterning defects, and significant pre- and postnatal lethality. The recent description of mutations in WTX underlying OSCS has led to the identification of a milder, survivable phenotype in males. Individuals with this presentation can have, in addition to skeletal sclerosis, Hirschsprung disease, joint contractures, cardiomyopathy, and neuromuscular anomalies. A diagnosis of OSCS should be considered in males with macrocephaly, skeletal sclerosis that is most marked in the cranium and the absence of metaphyseal striations. The observation of striations in males may be indicative of a WTX mutation in a mosaic state supporting the contention that this sign in females is indicative of the differential lyonization of cells in the osteoblastic lineage.

Surgically assisted rapid maxillary expansion in two cases of osteopathia striata with cranial sclerosis

Osteopathia striata with cranial sclerosis (OS-CS) is a rare skeletal dysplasia characterized by linear striations of the long bones, osteosclerosis of the cranium, and extraskeletal anomalies. Osteosclerosis of the cranial and facial bones can lead to disfigurement and to disability due to the pressure on the cranial nerves. We report two cases of OS-CS where surgically assisted rapid maxillary expansion was performed for widening the extremely narrow maxilla. One should be aware of the disease-related problems and the possible complications that might occur with this type of patient.

Osteopathia striata with cranial sclerosis and lumbar spinal stenosis

Osteopathia striata with cranial sclerosis is one of the dysplasias of endochondral bone formation. We report a patient with this condition combined with lumbar spinal stenosis and intervertebral disc herniation. This coexistence has not been previously reported in the medical literature. The possible mechanisms of this clinical association is discussed.

Osteopathia striata-cranial sclerosis: otorhinolaryngologic clinical presentation and radiologic findings

BACKGROUND

Osteopathia striata with cranial sclerosis (OS-CS) is a rare bone dysplasia that presents with variable symptoms mainly due to the associated CS.

METHODS

The otorhinolaryngologic clinical presentation and temporal bone computed tomography (CT) findings of a new case of OS-CS are presented. Differential diagnosis is also discussed.

RESULTS

Our study confirms the typical appearance of the temporal bone reported in previous CT studies and the utility of CT for evaluating the various etiologies of conductive-mixed hearing loss present in OS-CS. Radiographs of the femur and pelvis revealed the typical striations of OS-CS and allowed us to diagnose this rare form of generalized skeletal dysplasia involving the skull base.

CONCLUSIONS

To our knowledge, this is the third reported case of OS-CS in which temporal bone CT evaluation corroborated the smallness of the middle ear cavities, abnormal ossicular fixation, and bone sclerosis of the mastoid cells. Other radiographic studies regarding the whole skeleton may, in combination, be very helpful in the differential diagnosis between the different forms of generalized skeletal diseases with bone sclerosis involving the skull base.