Proband and the Brother.

INTRODUCTION: Camurati-Engelmann disease (CED) is a rare autosomal dominant disease. It is characterized by hyperostosis of the long bones and the skull, Clinically patient will have limb pain, proximal muscle weakness a wide-based gait. The gene causing CED is located on chromosome 19, this region contains the gene encoding the TGF Beta -1. The diagnosis of CED is established in a proband with the characteristic radiographic findings and molecular genetic testing for TGF Beta-1 mutation. Treatment is with corticosteroids and Losartan. MATERIALS: A 40 year old lady presented with complaints of Left lower limb pain for 1 year duration. On examination there was tenderness of left greater trochanter, proximal and distal femur was present. Blood investigations showed high PTH and low Vitamin-D3. Imaging showed non specific sclerotic lesions in femur. As patient brother had limp since childhood genetic disorders were and a provisional diagnosis of sclerotic bone disease probable Progressive diaphyseal dysplasia was considered. PET-CT was done which revealed abnormal osteoblastic activity in both femurs, focal hyperostosis in humeral diaphysis suggestive of CED. She was tested Positive for TGF beta 1 mutation consistent with CED. He was started on LOSARTAN. On follow up patient is pain free. RESULT: Her brother was also evaluated in view of his limp and he was also diagnosed as CED. CONCLUSION: The diagnosis in this case was based on the clinical history, family history and characteristic radiological findings and genetic testing which confirmed TGF Beta-1 mutation. Family history is crucial in this case which led to diagnosis. References Van Hul W, Boudin E, Vanhoenacker FM, et al. Camurati Engelmann disease. Calcif Tissue Int 2019;104(5):554-560. Camurati-Engelmann Disease. NORD (National Organization for Rare Disorders); 2022.

Clinical characteristics and the influence of rs1800470 in patients with Camurati-Engelmann disease.

Background: Camurati-Engelmann disease (CED) is a sclerosing bone dysplasia caused by transforming growth factor ß1 (TGFB1) gene variants. Objective: We aim to summarize the clinical characteristics and the efficacy of glucocorticoids in 14 individuals with CED, and explore the correlation between the phenotype and the SNP of rs1800470 (c.29C>T). Methods: Clinical, biochemical, radiological, and therapeutic data were collected from 14 patients. DNA was extracted for TGFB1 variants detection by Sanger sequencing. Results: The median onset and record age were 3.0 and 16.1 years, respectively. All patients manifested bone pain and decreased subcutaneous fat tissue. Inflammatory markers increased in over 60% of patients, and the median erythrocyte sedimentation rate (ESR) was 1.40 (0.50~3.67) of the upper limit of normal (ULN), and the median high sensitivity C reactive protein (hsCRP) was 1.71 (0.48~12.56) of ULN. There was a positive correlation between ESR and hsCRP (rs=0.806, p=0.003). Both ESR and hsCRP were negatively correlated with the levels of hemoglobin (HGB), calcium, and creatinine, but positively correlated with the level of alkaline phosphatase. Four known variants of TGFB1 were identified, including p.Tyr171Cys, p.Arg218Cys, p.Arg218His, and p.Cys225Arg. Moreover, 35.7% and 28.6% of them carried the heterozygous and homozygous SNP of c.29C>T, called C/T and T/T groups, respectively, but 35.7% of them were without c.29C>T (C/C group). The onset age, anthropometric data, percentages of different clinical manifestations, and biochemical parameters were comparable among the three groups. But there were increasing trends in levels of HGB and calcium and decreasing trends in ESR and hsCRP among C/C, C/T, and T/T groups in turn. Glucocorticoid improves the two inflammatory markers among CED patients. Conclusion: The phenotype of CED is highly heterogeneous. There is no clear genotype-phenotype correlation, but it seems to have better trends of biochemical parameters in patients with CED carrying the T allele of rs1800470.

Improvement of Bone Health and Initiation of Puberty Development in Camurati-Engelmann Disease With Glucocorticoid and Losartan Treatment: A Case Report and Review of Literature.

Camurati-Engelmann Disease (CED) is a rare sclerosing bone disease, sometimes associated delayed puberty. The treatment effect of glucocorticoid and angiotensin II receptor blocker (ARB) in bone health and puberty development remain unclear. We report a case of an 18-year-old girl who presented for a history of an enlarged head, pain of lower limbs, and no menstrual onset or breast development. Radiographs revealed thickening of skull and cortices in the diaphysis but sparse bone trabeculae in the spine and metaphysis. Sanger sequencing detected a mutation of c. 652C>T (p. R218C) in the gene TGFB1 and confirmed the diagnosis of CED. After treatment of a medium-to-small dosage of prednisone and losartan for 28 months, we observed improvement of bone mass in spine and hip and body fat mass and found initiation of puberty development. By a systemic review of current treatment strategies in patients with CED, we found that most cases reported relief of bone pain with treatment of glucocorticoid or ARB, but none has reported the outcome of hypogonadotropic hypogonadism. We propose that long-term use of glucocorticoid combined with ARB may inhibit the activation of TGFß1 in CED, improve adipogenesis, and thus initiate puberty development and improve the bone mass in spine and hip.

Clinical characteristics and identification of a novel TGFB1 variant in three unrelated Chinese families with Camurati-Engelmann disease.

BACKGROUND: To investigate the clinical characteristics and molecular diagnosis of Camurati-Engelmann disease (CAEND) in Chinese individuals. METHODS: We recruited six patients aged 14 to 45 years in three unrelated families with CAEND, including five females and one male. Clinical manifestations, biochemical tests, and radiographic examinations were analyzed. The TGFB1 gene variants were further identified by Sanger sequencing. In addition, one female patient was followed up for 5 years. RESULTS: The onset age of the patients ranged from 1 to 6 years. All of them had family histories and consisted of an autosomal dominant inheritance pattern. Gait disturbance, fatigue, progressive bone pain, muscle atrophy, and weakness were the main complaints. Laboratory examinations revealed that the inflammatory markers were at high levels, in addition to the increased bone metabolism indicators. The thickened diaphysis of long bones and the narrowed medullary cavity was observed by radiography. Furthermore, bone scintigraphy detected abnormal symmetrical radioactive concentrations in the affected regions of bone. Sanger sequencing identified a missense heterozygous variant in exon 4 of the TGFB1 gene in families 1 and 2, resulting in Arg218Cys, which confirmed CAEND. Moreover, one novel variant c.669C > G in exon 4 of the TGFB1 gene harboring Cys223Trp was detected in family 3. Subsequent bioinformatics software predicted that the novel variant was pathogenic. Of interest, III:2 in family 3 experienced heart valve defects and tachycardia at birth, which had never been reported in CAEND patients before. Moreover, the response to drug treatment is also full of contradictions and is worthy of further study. CONCLUSION: Besides the typical CAEND manifestations, the new phenotypic characteristics of tachycardia and heart valve defects were first reported in one woman carrying the novel variant p.Cys223Trp in TGFB1 the gene. In addition, we demonstrated that increased bone metabolism indicators and inflammatory markers may possess auxiliary diagnosis for CAEND.

Looking for the skeleton in the closet-rare genetic diagnoses in patients with diabetes and skeletal manifestations.

AIMS: The precision medicine approach of tailoring treatment to the individual characteristics of each patient has been a great success in monogenic diabetes subtypes, highlighting the importance of accurate clinical and genetic diagnoses of the type of diabetes. We sought to describe three unique cases of childhood-onset diabetes in whom skeletal manifestations led to the revelation of a rare type of diabetes. METHODS : Case-scenarios and review of the literature. RESULTS: Case 1: A homozygous mutation in TRMT10A, a tRNA methyltransferase, was identified in a 15-year-old boy with new-onset diabetes, developmental delay, microcephaly, dysmorphism, short stature and central obesity. The progressive apoptosis of pancreatic beta cells required insulin replacement therapy, with increased demand due to an unfavorable body composition. Case 2: Congenital generalized lipodystrophy type 1 was suspected in an adolescent male with an acromegaloid facial appearance, muscular habitus, and diabetes who presented with a pathological fracture in a cystic bone lesion. A homozygous mutation in AGPAT2, an acyl transferase which mediates the formation of phospholipid precursors, was identified. Leptin replacement therapy initiation resulted in a remarkable improvement in clinical parameters. Case 3: A 12-year-old boy with progressive lower limb weakness and pain was diagnosed with diabetic ketoacidosis. Diffuse diaphyseal osteosclerosis compatible with the diagnosis of Camurati-Engelmann disease and a heterozygous mutation in TGFß1 were identified. Preservation of euglycemia by insulin replacement relieved pain, suggesting that the diabetic milieu may have augmented TGFß1 overexpression. CONCLUSION: Unraveling the precise genetic cause for the clinical manifestations led to the prediction of phenotypic manifestations, and enhanced the clinical outcomes.

Surgery Treatment of an Adult Patient with Camurati-Engelmann Disease: A Case Report.

CASE: A 40-year-old Colombian woman presented with a 7-year history of progressive lower-limb pain. Sclerosis of the diaphyseal tibia and femur was observed in her latest x-ray images. A narrowing of the medullary canal is observed in Camurati-Engelmann disease (CED), a rare and progressive diaphyseal dysplasia that was confirmed in this patient by genetic testing. Medical treatment was unsuccessful; thus, surgical treatment consisted of decompression by drilling of the medullary canal was performed, achieving successful pain release. CONCLUSION: Surgical treatment should be considered for patients with CED when the medical treatment is unsuccessful because doing so reduces bone overgrowth, leading to pain relief.

A new LRP6 variant and Camurati-Engelmann-like disease.

INTRODUCTION: Camurati-Engelmann disease is a rare autosomal dominant bone dysplasia belonging to the group of craniotubular hyperostoses. Genetic analysis classically shows mutation on TGFß1 gene. CASE REPORT: A young woman was hospitalized with intense pain in lower limbs, associated to radiographic hyperostosis and sclerosis of the long bones. RESULTS: Mutation on LRP6 has recently been associated to high bone mass. In this case report, a rare missense variant on LRP6 gene was associated to radiographic features of Camurati-Engelmann. CONCLUSIONS: More studies should be conducted to assess the pathological role of this variant in Camurati-Engelmann-like disease.

A Case Report of a 44-Year-Old Woman With Camurati-Englemann Disease: A Case Report.

CASE: A 44-year-old woman presented with easy fatigability, diplopia, dizziness, and a 2-year history of pelvic, hip, and lower extremity aching and pain. Radiograph, magnetic resonance imaging, computed tomography, and histopathologic imaging studies were obtained. Hypersclerosis of the affected bones led to the initiation of a sclerotic bone dysplasia workup and sequencing of the transforming growth factor beta 1 gene located on chromosome 19q13 revealed a heterozygous rare missense variant in exon-4, leading to a final diagnosis of Camurati-Engelmann disease (CED). Medical treatment thus far has had a minimal effect on her symptoms, and the patient continues to be followed. CONCLUSIONS: This specific mutation has been reported only once previously in a patient with CED. This case report expands the typical phenotype associated with CED in association with the c.667T>C, p.Cys223Arg variant.

Genetic testing is useful in adults with limited phenotypes of genetic skeletal conditions.

We show the value of genetic screening in 3 adults with limited phenotypes of three bone sclerosing genetic disease (GD): osteopetrosis (OPT), Camurati-Engelmann disease (CED) and pycnodysostosis. INTRODUCTION: OPT, CED and pycnodysostosis are three rare bone diseases often diagnosed in childhood. However, some atypical phenotypes raise the problem of delayed diagnosis in adults. Genetic tests may then be useful to establish a formal diagnosis. METHODS: We report 3 cases of adult patients with symptomatic or asymptomatic bone sclerosing lesions for whom the clinical, radiological and biological explorations were atypical and did not allow a formal diagnosis. These unusual descriptions led to the search for genetic mutations. RESULTS: These 3 cases of limited phenotypes were associated with unknown or poorly described variants of 3 rare bone genetic diseases. CONCLUSIONS: Genetic tests proved useful to establish the diagnosis and manage the condition of adults with rare bone sclerosing GD.

Observations on the Natural History of Camurati-Engelmann Disease.

Camurati-Engelmann disease (OMIM 31300) is a rare cranio-tubular bone dysplasia characterized by osteosclerosis of the long bones and skull caused by dominantly-inherited mutations in the transforming growth factor beta 1 (TGFB1) gene. A wide variation in phenotype has been recognized, even within families carrying the same mutation. In addition, aspects of the natural history of the disorder, in particular whether it is always progressive or can remit spontaneously, remain uncertain. In a large kindred carrying a TGFB1 gene mutation (c.653G > A; p.R218H) we have attempted to clarify the extent of phenotypic variability and the natural history of the disease through detailed individual histories of symptoms, and skeletal imaging by both radiography and scintigraphy. Only one subject had the classical childhood onset with bone pain in the legs and gait disturbance. Eight subjects reported the onset of leg pain in their teenage years that, by their early 20s, had either resolved or persisted at a low level. Two of these eight later developed cranial nerve palsies. There was a wide variation in the radiographic appearance in adults, but disease extent and activity in long bones, as assessed by scintigraphy, was inversely correlated with age (p < 0.025). In younger subjects the radiographic and scintigraphic appearances were concordant, but in older subjects the scintigram could be quiescent despite florid radiographic changes. Sequential scintigrams in two subjects showed reduced activity in the later scan. One subject had suffered meningoencephalitis in early childhood that resulted in paresis of one arm. The affected arm showed markedly less disease involvement, implicating mechanical or growth factors in its etiology. Our data suggest that the natural history of Camurati-Engelmann disease can be benign, and that disease activity commonly attenuates in adulthood. Severe cases of childhood onset and/or with cranial nerve involvement, may occur only in a minority of mutation carriers. © 2019 American Society for Bone and Mineral Research.

Bone-targeted delivery of TGF-ß type 1 receptor inhibitor rescues uncoupled bone remodeling in Camurati-Engelmann disease.

Camurati-Engelmann disease (CED) is a genetic bone-modeling disorder mainly caused by mutations in the gene that encodes transforming growth factor-ß1 (TGF-ß1). Symptoms of CED include bone pain, fractures, and dysplasia. Currently, effective therapies for bone fracture and dysplasia in CED are urgently needed. We have demonstrated that TGF-ß1 is a coupling factor for bone remodeling and is aberrantly activated in CED. Daily injection of TGF-ß type 1 receptor inhibitor (TßR1I) attenuated CED symptoms, but this systemic administration caused serious side effects. In this study, we created a conjugate linking TßR1I and alendronate, which delivered TßR1I specifically to bone. After weekly injection of the conjugate for 8 weeks, normal bone morphology and remodeling in CED mice was maintained with a minimum effective dose 700 times lower than TßR1I injection. Additionally, we found that the conjugate restored normal bone turnover by reducing the number of osteoblasts and osteoclasts, maintained a regular osteogenic microenvironment by regulating the formation of CD31 and Endomucin double-positive vessels, and preserved ordinary bone formation via inhibition of the migration of leptin-receptor-positive cells. Thus, targeting delivery of TßR1I to bone is a promising therapy for CED and other uncoupled bone remodeling disorders.

Clinical characteristics and treatment outcomes in Camurati-Engelmann disease: A case series.

BACKGROUND: Camurati-Engelmann disease is an extremely rare disease characterized by hyperostosis of multiple long bones. This condition is caused by heterozygous mutations in the TGFB1 gene. METHODS: We describe the clinical and genetic characteristics of 4 Korean patients with this rare disease diagnosed at Asan Medical Center in Korea between June 2012 and May 2016, to increase awareness about this condition among general physicians and orthopedists. The presenting features, biochemical findings, radiographic and nuclear imaging findings, molecular analysis, and treatment outcomes of 4 patients were reviewed retrospectively. RESULTS: Two patients had sporadic disease, whereas the other 2 were familial cases. The average age at symptom onset was 8.8 ±â€Š5.5 (4-14) years. Symptoms included waddling gait or leg pain. Bone pain and easy fatigability were documented in all patients. Skeletal deformities such as osteoporosis, genu valgum, and severe scoliosis were observed. Visual and otologic manifestations presenting as exophthalmos, retinal detachment, and vestibulopathy were found in 3 patients. Skeletal survey showed diaphyseal expansion with diffuse cortical thickening of long bones in all patients. Bone scintigraphy images showed increased uptake of radioactive material in the calvarium and diaphysis of long bones. The mean erythrocyte sedimentation rate was 46.5 ±â€Š22.2 (20-72) mm/h. Sequence analysis of TGFB1 revealed the previously reported mutations p.Arg218His, p.Arg218Cys, and p.Glu169Lys. Corticosteroid was effective in relieving pain, and losartan was used as maintenance therapy. CONCLUSIONS: Our experience suggests that this rare condition can be suspected in patients with characteristic symptoms and skeletal findings. Considering the presence of effective medical treatment, efforts are needed to identify more cases.

Pain improvement in Camurati-Engelmann disease after anti-TNFα therapy.

Camurati-Engelmann disease (CED) is a rare disorder included in the group of craniotubular hyperostosis diseases. Corticosteroids are used for pain management in CED, but in refractory or corticosteroid-non-tolerant patients, pain management is limited. We report the case of a woman with CED diagnosed in early infancy whose initial complaints included persistent bone pain associated with progressive functional disability. She was treated with steroids but over time became dependent on higher doses with only mild pain relief. In her third decade, she was diagnosed with ulcerative colitis (UC) and was treated with mesalazine, azathioprine and prednisolone. Due to recurrent exacerbations of UC, treatment was changed to infliximab, an antitumour necrosis factor-alpha (TNFα). Remission of UC was achieved and CED-associated pain also improved with infliximab. This is the first report showing a possible role of anti-TNFα in pain management in CED with unsatisfactory response to steroids.

Discrepancy between bone density and bone material strength index in three siblings with Camurati-Engelmann disease.

Camurati-Engelmann (CE) is a very rare disease affecting one in every million persons worldwide. It is characterized by an enlargement of long bones. We aimed to assess bone characteristics in three siblings with different tools. Even if there was an excess of bone density, quality seemed to be deteriorated. INTRODUCTION: CE disease is a rare monogenic disorder affecting approximately one in every million persons worldwide. It is mainly characterized by a progressive hyperostosis of the periosteum and endosteum of the diaphysis of long bones. Limited data are available about bone characteristics in these patients. In three siblings with CE disease, we aimed to assess bone mineral density (BMD) and trabecular bone score (TBS) by dual-energy X-ray absorptiometry (DXA) and material characteristics at tissue level using bone impact reference point indentation. METHODS: Clinical data were collected and a general laboratory workup was performed. At the lumbar spine and hip, BMD and TBS were measured using DXA imaging. Bone material strength index (BMSi) was measured by bone impact microindentation using an Osteoprobe instrument. RESULTS: All three cases had densitometric values consistent with high bone mass (sum of Z-score at the lumbar spine and hip > 4). Hip BMD was extremely high in all three siblings at both total hip and femoral neck, while at the lumbar spine, two of them had normal values but the third again had very high BMD. TBS values were in the normal range. In contrast, BMSi measurements were at low or very low levels, compared with normal controls. CONCLUSION: Despite strikingly increased BMD and normal microarchitecture, BMSi is affected in patients with CE. Microindentation could be an appropriate tool for assessing bone fragility in these patients. Bone disease in this group of patients requires further study to better understand the underlying regulatory mechanisms and their alterations.

Orthopedic Manifestations of Type I Camurati-Engelmann Disease.

BACKGROUND: Camurati-Engelmann disease (CED) is a rare genetic skeletal disorder characterized by limb pain, muscle emaciation and weakness, and cortical thickening of the diaphysis of long bones. It is caused by mutations in the transforming growth factor beta 1 (TGFB1) (type I) or other unknown gene(s) (type II). We present 8 consecutive patients with type I CED. METHODS: We retrospectively reviewed medical records and radiographs of type I CED patients with special reference to the mode of presentation, process of diagnostic work-up, and disease course. They were 4 sporadic patients, and two pairs of mother and son. RESULTS: We categorized the mode of presentation into three groups. Group I had 4 patients who mainly presented with motor disturbances in young age. They drew medical attention for waddling gait, awkward ambulation or running, difficulty in going upstairs, or a positive Gower's sign at age 4 to 6 years. Subsequent development of limb pain and radiographic abnormality led to the diagnosis of CED at age 6 to 29 years. Group II had 3 patients who mainly presented with limb pain at age 15, 20, and 54 years, respectively. Radiographic evaluation and molecular genetic test led to the diagnosis of CED. The remaining 1 patient (group III) was asymptomatic until age 9 years when bony lesions at the tibiae were found incidentally. For the last 10 years, he intermittently complained of leg pain in the morning or after sports activities, which did not interfere with daily life. All the patients in group I showed a body mass index in the underweight range (< 18.4 kg/m2). At the latest follow-up, 4 patients in groups I and II required medication for the limb pain. CONCLUSIONS: CED presents with a wide range of severity. Awareness of this rare disease entity may be the key to timely correct diagnosis. This disease entity should be considered in the differential diagnosis of limb pain or motor disturbance in children to avoid unnecessary diagnostic work-up.

Clinical diagnosis and mutation analysis of a Chinese family with Camurati-Engelmann disease.

Camurati-Engelmann disease (CED) is a rare autosomal dominant bone disorder caused by a mutation in transforming growth factor ß1 (TGFß1). The present study aimed to identify a Chinese family with suspected CED based on the clinical symptoms, including pain in extremities, waddling gait, muscle weakness, cortical thickening of the diaphysis of the long bones, and sclerosis of the skull, facial bone, and pelvis. Molecular analysis revealed the presence of the p.Glu169Lys (E169K) mutation in exon 2 of TGFß1 in patients when compared with the controls. Therefore, the Chinese family was diagnosed with CED due to the presence of the E169K mutation. The present study emphasized the importance of clinical and genetic evidence for the diagnosis of CED. The data presented in the present study are of significance to clinicians, as well as genetic counselors, in the prenatal screening of CED.

An ENU-induced p.C225S missense mutation in the mouse Tgfb1 gene does not cause Camurati-Engelmann disease-like skeletal phenotypes.

Camurati-Engelmann disease (CED) is a rare sclerosing bone disorder in humans with autosomal dominant inheritance. Mutations in the gene (TGFB1) that encodes transforming growth factor-ß1 (TGF-ß1) are causative for CED. TGF-ß1 signaling is enhanced by the CED-causing mutations. In this study, we performed Tgfb1 mutation screening in an ENU-mutagenized mouse genomic DNA library. We identified a missense mutation in which cysteine was substituted by serine at position 225 (p.C225S), that corresponded to the CED-causing mutation (p.C225R). TGF-ß1 mutant protein carrying p.C225S was secreted normally into the extracellular space. Reporter gene assays showed that the p.C225S mutants enhanced TGF-ß signaling at the same level as p.C225R mutants. We generated p.C225S homozygous mice and confirmed that the mature TGF-ß1 levels in the culture supernatants of the calvarial cells from the homozygotes were significantly higher than those from wild-type mice. Although the skull and femur are sclerotic in CED, these phenotypes were not observed in p.C225S homozygous mice. These results suggest that human and mouse bone tissue react differently to TGF-ß1. These findings are useful to pharmacological studies using mouse models in developing drugs that will target TGF-ß signaling.

Mild Camurati­Engelamann disease presenting with exophthalmos as the first and only manifestation: A case report.

Camurati-Engelmann disease (CED; MIM 131300), or progressive diaphyseal dysplasia, is a rare autosomal dominant bone disease, which is caused by mutations in the transforming growth factor­ß1 (TGFß1) gene on chromosome 19q13.1­13.3. Extremely variable penetrance has been reported to be associated with CED, the most common features of which are limb pain, waddling gait and muscle weakness. The present study reported on a consanguineous Chinese family with one affected individual that initially presented with exophthalmos, which has not previously been reported as an initial manifestation of CED. The proband was a 22-year-old woman that presented with progressive proptosis. Except for increased serum levels of alkaline phosphatase and C­terminal telopeptide of type I collagen, no other biochemical abnormalities were detected. Whole­body radiological and bone scintigraphic investigations revealed that hyperostosis and sclerosis predominantly affected the cranial bones, including the skull base, and only mildly affected the long bones. A heterozygous mutation involving a G to A transition at the cDNA position +653 of TGFß1 was detected in the patient only, but not in her family members, by automated DNA sequencing using an ABI DNA sequencer (Model 377). Based on the clinical, biochemical, radiological and genetic findings, a diagnosis of CED was confirmed. Considering the phenotypic variability associated with CED and the unique manifestations of the patient described in the present study, CED should be taken into account regarding the differential diagnosis of exophthalmos.

[Camurati-Engelmann disease].

Camurati-Engelmann disease (CAEND, OMIM 131300) is a rare autosomal dominant, progressive diaphyseal dysplasia, which is characterized by hyperosteosis and sclerosis of the diaphyses of long bones. Estimated number of patients with CAEND in Japan is approximately 50-60 by our epidemiological survey. We have reported that domain-specific mutations in transforming growth factor-ß1 gene(TGFB1) cause CAEND. Mutations in latency associated peptide(LAP) domain of TGF-ß1 destabilize the complex and may hyperactivate TGF signal pathway. We tried to establish CAEND model mice by gene-targeting, but could not because of spermatogenesis defects in chimera mice. We also failed using CRISPR/Cas9 system. Alternatively, we established CAEND patient-derived iPS cells, and are advancing research with them to develop novel therapeutic agents for CAEND.

Miscellaneous Bone Disorders.

This chapter deals with a few of the important childhood bone disorders associated with high bone mass as well as conditions associated with fragility fractures and limb deformities that have not been addressed in previous chapters. A couple of skeletal dysplasias that can sometimes be confused with rickets are also dealt with in this chapter.