Buschke-Ollendorff syndrome presenting with asymptomatic yellowish papules and leg length discrepancy: A case report.

Buschke-Ollendorff syndrome (BOS) is a rare, usually benign, autosomal dominant genetic disease affecting about 0.005% globally. BOS commonly manifests with asymptomatic connective tissue nevi, sometimes with sclerotic bone lesions like osteopoikilosis or melorheostosis. However, BOS may develop severe, symptomatic complications that require surgical intervention. Here we report a 9-year-8-month girl presenting with multiple nonpruritic, nonpainful skin plaques scattered around the trunk, buttocks, and bilateral legs. She had a history of right varus foot with inadequate plantar flexion. Upon visiting, obvious leg length discrepancy (LLD) was noted. Lesional biopsy revealed increased fibroblasts within dermal collagen bundles. Verhoeff-van Gieson stain revealed scattered foci of thickened elastic fibers between collagen fibers, especially in the mid-dermis. Radiographic examination of the lower extremities showed multiple small, round-to-oval shaped, radiopaque spots on the pelvic bones, femurs, tibiae, and both feet. Hyperostosis along the long axis with "dripping candle wax" appearance was characteristic of osteopoikilosis and melorheostosis. Genetic analysis showed heterozygous point mutation in exon 1 of LEMD3 gene (c.1323C>A, p.Y441X), confirming diagnosis of BOS. Sequential and epiphyseodesis were performed to correct LLD with a favorable outcome at 2-year follow-up. BOS associated with severe bone abnormalities is rare, but orthopedic surgical intervention can provide satisfactory outcome.

Spotted bones in an osteopoikilosis-related disease (Buschke Ollendorff Syndrome): Identifying this rare condition from the lab to the field.

OBJECTIVE: To improve the differential diagnosis of osteopoikilosis in past populations using a clinical case as an example of this rare condition. MATERIALS: A patient referred to our Genetic Service with suspected Buschke Ollendorff Syndrome after finding a connective nevus. METHODS: Radiological images from different body regions were accompanied by a genetic study using next-generation sequencing. RESULTS: Small circular-to-ellipsoid sclerotic lesions were found in the epiphysis and metaphysis of long bones, as well as in the pelvis. These lesions were bilaterally distributed and with well-defined margins, compatible with the characteristics of Buschke Ollendorff Syndrome, bone manifestation osteopoikilosis. A heterozygous mutation on LEMD3 (NM_001167614:c.1918 + 1G > C) was identified by next-generation sequencing. Based on this confirmed case, we have discussed the most probable causes of similar bone lesions found in the archaeological record. CONCLUSION: It has been demonstrated how a current case of a rare disease can provide useful tools to improve the differential diagnosis of this disease in ancient skeletons. SIGNIFICANCE: This work underlines the great need for multidisciplinary platforms that integrates clinical research into paleopathology in order to successfully address the study of rare diseases from the past. LIMITATIONS: Since OPK is only detected by X-rays, suspected cases of this bone lesion will only be identified when radiographs are taken for other purposes. SUGGESTIONS FOR FURTHER RESEARCH: Retrospective and large-scale studies of radiographs from other research in past populations.

Buschke-Ollendorff syndrome with LEMD3 germline stopgain mutation p.R678* presenting as multiple subcutaneous nodules with mucin deposition.

Buschke-Ollendorff syndrome (BOS; OMIM 166700) is a rare autosomal dominant disorder characterized by the existence of connective tissue nevus and/or osteopoikilosis. The skin lesions usually present as firm, yellow, or flesh-colored papules and nodules, which may coalesce into plaques and increase in size and number over time. We present a case of a 26-year-old male with multiple subcutaneous nodules on the waist and thigh for more than 20 years. Being deeply seated, his skin lesions were not visible and could only be appreciated by palpation. Accordingly, pathology showed an increase in thick, crossed, or paralleled, elastic fibers arranged between the collagen bundles in the lower part of the reticular dermis and the subcutaneous fat with mucin deposition. Heterozygous point mutation in exon 8 of the LEMD3 gene was detected, which confirmed the diagnosis of BOS. The deeply situated nature of skin lesions noted in our case has not been reported in the literature of BOS. Our case thus expands the clinical and pathological features of the disease.

Modeling-based bone formation transforms trabeculae to cortical bone in the sclerotic areas in Buschke-Ollendorff syndrome. A case study of two females with LEMD3 variants.

Buschke-Ollendorff syndrome is a rare autosomal dominant condition caused by pathogenic variants in LEMD3 and characterized by connective tissue nevi and sclerotic bone abnormalities known as osteopoikilosis. The bone phenotype in Buschke-Ollendorff syndrome including osteopoikilosis remains unclear. We investigated bone turnover markers, pelvis and crura X-rays; lumbar spine and femoral neck DXA; bone activity by NaF-PET/CT, bone structure by µCT and dynamic histomorphometry in adults with Buschke-Ollendorff syndrome. Two women aged 25 and 47 years with a BMI of 30 and 32 kg/m2, respectively, were included in the investigation. Bone turnover markers were within normal range. aBMD Z-scores were comparable to that of controls in the lumbar spine and increased at the hip. Radiographies exposed spotted areas in crura and pelvis, and NaF-PET/CT exposed abnormal pattern of irregular shaped NaF uptake in the entire skeleton. In both biopsies, µCT showed trabecular structure comparable to that of controls with stellate shaped sclerotic noduli within the cavity and on the endocortex. Histomorphometric analyses of the sclerotic lesions revealed compact lamellar bone with a normal bone remodeling rate, but partly replaced by modeling-based bone formation. Woven bone was not observed in the nodules. Therefore, while bone turnover and BMD were largely within normal reference range in patients with the Buschke-Ollendorff syndrome, osteosclerotic lesions appear to emerge due to modeling-based bone formation with secondary bone remodeling. These observations indicate that LEMD3 may be important for the activation of bone lining cells leading to modeling-based bone formation.

Depressed indurated plaque with elastorrhexis as a distinctive lesion in Buschke-Ollendorff syndrome.

Buschke-Ollendorff syndrome (BOS) is a rare autosomal dominant genodermatosis caused by heterozygous mutations in LEMD3 and characterized by connective tissue nevi and sclerotic bone lesions known as osteopoikilosis. We report a family with three individuals affected by BOS, two of whom manifested clinical and histopathological peculiarities, presenting with a depressed indurated plaque as the main cutaneous manifestation instead of the classic connective tissue nevi. Notable elastorrhexis was present in both biopsies.

Osteopoikilosis With Germline LEMD3 Mutation Mimicking Bone Metastases in a Girl With a Concurrent Secreting Mixed Germ Cell Tumor.

Osteopoikilosis (OPK) is a rare, benign, asymptomatic bone disease causing dense bone lesions, which could be interpreted as bone metastasis. The symmetric distribution, lack of bone destruction, and location differentiate OPK from metastatic disease. It is essential to be aware of this benign condition to prevent diagnostic errors. We present the case of a 10-year-old female patient with the concurrent diagnosis of secreting mixed germ cell tumor with Yolk Salk Tumor compound and OPK. Physical examination disclosed an abdominal mass, and blood tests showed increased alfa-fetoprotein and human chorionic gonadotropin levels. Computed tomography revealed a pelvic tumor associated with multiple radiodense lesions distributed throughout the bone skeleton. Lesions were inactive on scintigraphy and FDG-PET. Pathology of the bone showed normal bone tissue and ruled out metastasis. The patient achieved complete remission after chemotherapy and surgery and remains in continued complete remission 28 months from diagnosis. The genetic analysis confirmed the LEMD3 germline mutation confirming OPK.

Melorheostosis and Osteopoikilosis Clinical and Molecular Description of an Italian Case Series.

Melorheostosis (MEL) is an uncommon, sclerosing disease, characterised by hyperostosis of long bones, resembling the flowing of candle wax. The disease is sporadic and the pathogenesis is still poorly understood. Occasionally, the same family can include individuals with MEL and Osteopoikilosis (OPK), a disease characterised by multiple round foci of increased bone density. LEMD3 gene mutations are related to OPK and Buschke-Ollendorff Syndrome, a genetic condition in which an association between MEL, OPK and skin lesions is observed. In rare cases, LEMD3 mutations and recently mosaic MAP2K1 gene mutations have been correlated to MEL suggesting that somatic mosaicism could be causative of the disease. In this study, we described the clinical, radiological and molecular findings of 19 individuals with MEL and 8 with OPK and compared the results to the medical literature. The molecular analyses of this case series corroborate the available data in the medical literature, indicating that LEMD3 germline mutations are not a major cause of isolated MEL and reporting five further cases of OPK caused by LEMD3 germline mutations.

Melorheostosis and Osteopoikilosis: A Review of Clinical Features and Pathogenesis.

Melorheostosis is an exceptionally rare sclerosing hyperostosis that typically affects the appendicular skeleton in a limited segmental fashion. It occasionally occurs on a background of another benign generalised sclerosing bone condition, known as osteopoikilosis caused by germline mutations in LEMD3, encoding the inner nuclear membrane protein MAN1, which modulates TGFß/bone morphogenetic protein signalling. Recent studies of melorheostosis lesional tissue indicate that most cases arise from somatic MAP2K1 mutations although a small number may arise from other genes in related pathways, such as KRAS. Those cases associated with MAP2K1 mutations are more likely to have the classic "dripping candle wax" appearance on radiographs. The relationship between these somatic mutations and those found in a variety of malignant conditions is discussed. There are also similar germline mutations involved in a group of genetic disorders known as the RASopathies (including Noonan syndrome, Costello syndrome and various cardiofaciocutaneous syndromes), successful treatments for which could be applied to melorheostosis. The diagnosis and management of melorheostosis are discussed; there are 4 distinct radiographic patterns of melorheostosis and substantial overlap with mixed sclerosing bone dysplasia. Medical treatments include bisphosphonates, but definitive guidance on their use is lacking given the small number of patients that have been studied. Surgical intervention may be required for those with large bone growths, nerve entrapments, joint impingement syndromes or major limb deformities. Bone regrowth is uncommon after surgery, but recurrent contractures represent a major issue in those with extensive associated soft tissue involvement.

A novel LEMD3 pathogenic variant in a son and mother with osteopoikilosis.

Elmaogullari S, Yildiz AE, Demir S, Gürkan H, Uçaktürk SA. A novel LEMD3 pathogenic variant in a son and mother with osteopoikilosis. Turk J Pediatr 2019; 61: 594-598. Osteopoikilosis (OPK) is a rare, benign condition characterized by osteosclerotic foci that occur in the epiphyses and metaphyses of long bones, wrists, feet, ankles, pelvis, and scapulae. We report a 16-year-old boy and his mother incidentally found to have sclerotic lesions on X-ray. Both of them were asymptomatic and the bone scan of the boy ruled out osteoblastic metastases. We have shown that the boy and his mother have a previously unknown pathogenic variant of the LEMD3 gene, supporting the diagnosis of osteopoikilosis.

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.

Juvenile elastoma without germline mutations in LEMD3 gene: A case of Buschke-Ollendorff syndrome?

We report the case of a 6-year-old Caucasian girl with clinical and histopathologic features of Buschke-Ollendorff syndrome. Histologic examination of skin lesions showed thick, curly, elastic fibers in the derma. Bone lesions compatible with Buschke-Ollendorff syndrome were found in the girl's mother. Mutations in LEMD3 are pathogenic for Buschke-Ollendorff syndrome. Analysis of all exons and exon-intron junctions of LEMD3 did not reveal any germline mutations.

Novel 4-bp Intronic Deletion (c.1560+5_1560+8del) [corrected] in LEMD3 in a Korean Patient With Osteopoikilosis.

Osteopoikilosis is an autosomal dominant bone disorder characterized by symmetric multiple osteosclerotic lesions throughout the axial and appendicular skeleton. Pathogenic variants in the LEMD3 have been identified as the cause of osteopoikilosis. LEMD3 encodes an inner nuclear membrane protein that interacts with bone morphogenetic protein (BMP) and transforming growth factor (TGF)-ß pathways. We report the case of a 19-year-old man presenting with lower back pain and sciatica. His radiograph revealed bilateral and symmetrical multiple osteosclerotic bone lesions in both scapular areas. Sanger sequencing of LEMD3 revealed a four-base-pair deletion in intron 2 (c.1560+5_1560+8del), [corrected] which was inherited from his father. We found that this four-base-pair deletion in intron 2 causes aberrant splicing and consequent deletion of exon 2. To the best of our knowledge, this is the first report of genetically confirmed osteopoikilosis in Korea.

Melorheostosis: Exome sequencing of an associated dermatosis implicates postzygotic mosaicism of mutated KRAS.

Melorheostosis (MEL) is the rare sporadic dysostosis characterized by monostotic or polyostotic osteosclerosis and hyperostosis often distributed in a sclerotomal pattern. The prevailing hypothesis for MEL invokes postzygotic mosaicism. Sometimes scleroderma-like skin changes, considered a representation of the pathogenetic process of MEL, overlie the bony changes, and sometimes MEL becomes malignant. Osteopoikilosis (OPK) is the autosomal dominant skeletal dysplasia that features symmetrically distributed punctate osteosclerosis due to heterozygous loss-of-function mutation within LEMD3. Rarely, radiographic findings of MEL occur in OPK. However, germline mutation of LEMD3 does not explain sporadic MEL. To explore if mosaicism underlies MEL, we studied a boy with polyostotic MEL and characteristic overlying scleroderma-like skin, a few bony lesions consistent with OPK, and a large epidermal nevus known to usually harbor a HRAS, FGFR3, or PIK3CA gene mutation. Exome sequencing was performed to ~100× average read depth for his two dermatoses, two areas of normal skin, and peripheral blood leukocytes. As expected for non-malignant tissues, the patient's mutation burden in his normal skin and leukocytes was low. He, his mother, and his maternal grandfather carried a heterozygous, germline, in-frame, 24-base-pair deletion in LEMD3. Radiographs of the patient and his mother revealed bony foci consistent with OPK, but she showed no MEL. For the patient, somatic variant analysis, using four algorithms to compare all 20 possible pairwise combinations of his five DNA samples, identified only one high-confidence mutation, heterozygous KRAS Q61H (NM_033360.3:c.183A>C, NP_203524.1:p.Gln61His), in both his dermatoses but absent in his normal skin and blood. Thus, sparing our patient biopsy of his MEL bone, we identified a heterozygous somatic KRAS mutation in his scleroderma-like dermatosis considered a surrogate for MEL. This implicates postzygotic mosaicism of mutated KRAS, perhaps facilitated by germline LEMD3 haploinsufficiency, causing his MEL.

The Buschke-Ollendorff syndrome: a case report of simultaneous osteo-cutaneous malformations in the hand.

BACKGROUND: We describe a male with functionally impairing radial deviation of the thumb who presented to us at 24 years of age. Two sclerotic skin lesions had been excised 7 years before because of consecutive skin contracture. Latest radiological examination showed a spotted pattern consistent with osteopoikilosis. CASE PRESENTATION: A corrective osteotomy of the thumb was carried out due to the patients discomfort. Facing the simultaneous osteo-cutaneous malformation we postulated a Buschke-Ollendorff syndrome. Buschke-Ollendorff syndrome is a rare autosomal-dominant hereditary disorder of connective tissue with typical osteo-cutaneous manifestations. To explore our hypothesis, biopsies were taken from the affected bone lesions and surrounding skin and soft tissue for histological investigation and genetic testing of the LEMD3 gene was performed on blood of the patient. The histology showed typical changes of the bone architecture and a fibrotic collagenous nodule of the skin. The genetic testing on DNA extracted from peripheral blood leucocytes confirmed a heterozygous loss of function mutation in the LEM domain-containing protein 3 (LEMD3) gene coding for the inner nuclear membrane protein MAN1, which causes osteopoikilosis by antagonizing transforming growth factor ß (TGF-ß) and bone morphogenetic protein (BMP) signalling. CONCLUSIONS: In atypical cases of simultaneous occurrence of fibrotic skin lesions and a spotted pattern in the X-ray we recommend the genetic screening of the LEMD3 gene. A correct diagnosis of Buschke-Ollendorff syndrome is necessary to spare patients from expensive investigations and to provide reassurance about the benign nature of the disease.

Identification of a novel LEMD3 Y871X mutation in a three-generation family with osteopoikilosis and review of the literature.

INTRODUCTION: Osteopoikilosis is a rare and benign autosomal dominant genetic disorder, characterized by a symmetric but unequal distribution of multiple hyperostotic areas in different parts of the skeleton. Recent studies have reported loss-of-function mutations in the LEM domain containing 3 (LEMD3) gene, encoding an inner nuclear membrane protein, as a cause of osteopoikilosis. METHODS: We investigated LEMD3 gene in a three-generation family from China, with six patients affected with osteopoikilosis. Peripheral blood samples were collected from family members and 100 healthy controls. All exons of the LEMD3 gene and adjacent exon-intron sequences were amplified by PCR and subsequently sequenced. RESULTS: A novel heterozygous c.2612_2613insA (p.Y871X) mutation in exon 13 of LEMD3 was identified, which resulted in a frame shift predicted to generate a premature stop codon at amino acid position 871. The mutation co-segregates with the osteopoikilosis phenotype and was not found in 100 ethnically matched controls. CONCLUSION: We identified a new mutation in LEMD3 gene, accounting for the familial case of osteopoikilosis. In addition we also review the clinical manifestation, diagnosis and treatment of osteopoikilosis.

Novel Somatic Mutation in LEMD3 Splice Site Results in Buschke-Ollendorff Syndrome with Polyostotic Melorheostosis and Osteopoikilosis.

Buschke-Ollendorff syndrome is a rare autosomal dominant disorder caused by loss of function in LEMD3, resulting in connective tissue nevi and varying bone dysplasia. Although typically benign, we describe a novel LEMD3 splice site mutation (IVS12 + 1delG) in a 13-year-old boy with Buschke-Ollendorff syndrome presenting with severe skeletal deformities, polyostotic melorheostosis, and osteopoikilosis.

Buschke-Ollendorff syndrome: sparing unnecessary investigations.

Buschke-Ollendorff syndrome (BOS) is an autosomal-dominant disease characterized by the association of connective tissue nevi and osteopoikilosis. It is diagnosed by mutations of proteins involved in bone and connective tissue morphogenesis. We report 2 cases of BOS with different cutaneous clinical patterns. These cases emphasize the importance of heightened suspicion of BOS in selected cases. Identifying BOS can be reassuring for the patient, sparing futile and expensive investigations.