Clinical and Molecular Diagnosis of Osteocraniostenosis in Fetuses and Newborns: Prenatal Ultrasound, Clinical, Radiological and Pathological Features.

Osteocraniostenosis (OCS, OMIM #602361) is a severe, usually lethal condition characterized by gracile bones with thin diaphyses, a cloverleaf-shaped skull and splenic hypo/aplasia. The condition is caused by heterozygous mutations in the FAM111A gene and is allelic to the non-lethal, dominant disorder Kenny-Caffey syndrome (KCS, OMIM #127000). Here we report two new cases of OCS, including one with a detailed pathological examination. We review the main diagnostic signs of OCS both before and after birth based on our observations and on the literature. We then review the current knowledge on the mutational spectrum of FAM111A associated with either OCS or KCS, including three novel variants, both from one of the OCS fetuses described here, and from further cases diagnosed at our centers. This report refines the previous knowledge on OCS and expands the mutational spectrum that results in either OCS or KCS.

Report of a novel variant in the FAM111A gene in a fetus with multiple anomalies including gracile bones, hypoplastic spleen, and hypomineralized skull.

Kenny-Caffey syndrome type 2 (KCS2) and osteocraniostenosis (OCS) are allelic disorders caused by heterozygous pathogenic variants in the FAM111A gene. Both conditions are characterized by gracile bones, characteristic facial features, hypomineralized skull with delayed closure of fontanelles and hypoparathyroidism. OCS and KCS2 are often referred to as FAM111A-related syndromes as a group; although OCS presents with a more severe, perinatal lethal phenotype. We report a novel FAM111A mutation in a fetus with poorly ossified skull, proportionate long extremities with thin diaphysis, and hypoplastic spleen consistent with FAM111A-related syndromes. Trio whole exome sequencing identified a p.Y562S de novo missense variant in the FAM111A gene. The variant shows significant similarity to other reported pathogenic mutations fitting proposed pathophysiologic mechanism which provide sufficient evidence for classification as likely pathogenic. Our report contributed a novel variant to the handful of OCS and KCS2 cases reported with pathogenic variants.

Overlapping phenotype comprising Kenny-Caffey type 2 and Sanjad-Sakati syndromes: The first case report.

Kenny-Caffey syndrome (KCS) is a rare hereditary skeletal disorder involving hypoparathyroidism. The autosomal dominant form (KCS2), caused by heterozygous pathogenic variants in the FAM111A gene, is distinguished from the autosomal recessive form (KCS1) and Sanjad-Sakati syndrome (SSS), both caused by pathogenic variants in the tubulin folding cofactor E (TBCE) gene, by the absence of microcephaly and intellectual disability. We present a patient with KCS2 caused by a de novo pathogenic variant c.1706G>A (p.Arg569His) in FAM111A gene, presenting intellectual disability and microcephaly, which are considered to be typical signs of SSS. We suggest that KCS1, KCS2, and SSS may not represent mutually exclusive clinical entities, but possibly an overlapping spectrum.

Hyperphosphatemic Tumoral Calcinosis: Pathogenesis, Clinical Presentation, and Challenges in Management.

Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare and disabling disorder of fibroblast growth factor 23 (FGF23) deficiency or resistance. The disorder is manifest by hyperphosphatemia, inappropriately increased tubular reabsorption of phosphate and 1,25-dihydroxy-Vitamin D, and ectopic calcifications. HFTC has been associated with autosomal recessive pathogenic variants in: (1) the gene encoding FGF23; (2) GALNT3, which encodes a protein responsible for FGF23 glycosylation; and (3) KL, the gene encoding KLOTHO, a critical co-receptor for FGF23 signaling. An acquired autoimmune form of hyperphosphatemic tumoral calcinosis has also been reported. Periarticular tumoral calcinosis is the primary cause of disability in HFTC, leading to pain, reduced range-of-motion, and impaired physical function. Inflammatory disease is also prominent, including diaphysitis with cortical hyperostosis. Multiple treatment strategies have attempted to manage blood phosphate, reduce pain and inflammation, and address calcifications and their complications. Unfortunately, efficacy data are limited to case reports and small cohorts, and no clearly effective therapies have been identified. The purpose of this review is to provide a background on pathogenesis and clinical presentation in HFTC, discuss current approaches to clinical management, and outline critical areas of need for future research.

Hyperphosphatemic familial tumoral calcinosis caused by a novel variant in the GALNT3 gene.

AIM: Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare endocrine disorder caused by autosomal recessive variants in GALNT3, FGF23, and KL leading to progressive calcification of soft tissues and subsequent clinical effects. The aim of this was to study the cause of HFTC in an Iranian family. PATIENTS AND METHODS: Four generations of a family with HFTC were studied for understanding the genetic pattern of the disease. Whole exome sequencing was applied on genomic DNA of the proband. Based on its result, genetically altered sequences were checked in his family through sanger sequencing. Then bioinformatics approaches as well as co-segregation analysis were applied to validate the genetic alteration. RESULTS: A novel homozygous variant in exon four of GALNT3, namely p.R261Q was found. The parents and sister were carriers. CONCLUSION: To our knowledge, it is the first-reported Iranian family with GALNT3-CDG novel variant.

Krüppel-like factor 3 inhibition by mutated lncRNA Reg1cp results in human high bone mass syndrome.

High bone mass (HBM) is usually caused by gene mutations, and its mechanism remains unclear. In the present study, we identified a novel mutation in the long noncoding RNA Reg1cp that is associated with HBM. Subsequent analysis in 1,465 Chinese subjects revealed that heterozygous Reg1cp individuals had higher bone density compared with subjects with WT Reg1cp Mutant Reg1cp increased the formation of the CD31hiEmcnhi endothelium in the bone marrow, which stimulated angiogenesis during osteogenesis. Mechanistically, mutant Reg1cp directly binds to Krüppel-like factor 3 (KLF3) to inhibit its activity. Mice depleted of Klf3 in endothelial cells showed a high abundance of CD31hiEmcnhi vessels and increased bone mass. Notably, we identified a natural compound, Ophiopogonin D, which functions as a KLF3 inhibitor. Administration of Ophiopogonin D increased the abundance of CD31hiEmcnhi vessels and bone formation. Our findings revealed a specific mutation in lncRNA Reg1cp that is involved in the pathogenesis of HBM and provides a new target to treat osteoporosis.

A Rare Case of Lethal Prenatal-Onset Infantile Cortical Hyperostosis.

Infantile cortical hyperostosis, or Caffey's disease, usually presents with typical radiological features of soft tissue swelling and cortical thickening of the underlying bone. The disease can be fatal when it presents antenatally, especially before a gestational age of 35 weeks. This fatal, premature form of the disease is known to occur in various ethnic groups around the globe, and approximately 30 cases have been reported in English literature. This paper is unique in that it is the first paper to report a lethal form of prenatal-type infantile cortical hyperostosis diagnosed in South Korea. Born at gestational age of 27 weeks and 4 days, the patient had typical features of polyhydramnios, anasarca, hyperostosis of multiple bones, micrognathia, pulmonary hypoplasia, and hepatomegaly. The patient was hypotonic, and due to pulmonary hypoplasia and persistent pulmonary hypertension, had to be supported with high frequency ventilation throughout the entire hospital course. Due to the disease entity itself, as well as prolonged parenteral nutrition, liver failure progressed, and the patient expired on day 38 when uncontrolled septic shock was superimposed. The chromosome karyotype of the patient was normal, 46, XX, and COL1A1 gene mutation was not detected.

Autoimmune hyperphosphatemic tumoral calcinosis in a patient with FGF23 autoantibodies.

Hyperphosphatemic familial tumoral calcinosis (HFTC)/hyperostosis-hyperphosphatemia syndrome (HHS) is an autosomal recessive disorder of ectopic calcification due to deficiency of or resistance to intact fibroblast growth factor 23 (iFGF23). Inactivating mutations in FGF23, N-acetylgalactosaminyltransferase 3 (GALNT3), or KLOTHO (KL) have been reported as causing HFTC/HHS. We present what we believe is the first identified case of autoimmune hyperphosphatemic tumoral calcinosis in an 8-year-old boy. In addition to the classical clinical and biochemical features of hyperphosphatemic tumoral calcinosis, the patient exhibited markedly elevated intact and C-terminal FGF23 levels, suggestive of FGF23 resistance. However, no mutations in FGF23, KL, or FGF receptor 1 (FGFR1) were identified. He subsequently developed type 1 diabetes mellitus, which raised the possibility of an autoimmune cause for hyperphosphatemic tumoral calcinosis. Luciferase immunoprecipitation systems revealed markedly elevated FGF23 autoantibodies without detectable FGFR1 or Klotho autoantibodies. Using an in vitro FGF23 functional assay, we found that the FGF23 autoantibodies in the patient's plasma blocked downstream signaling via the MAPK/ERK signaling pathway in a dose-dependent manner. Thus, this report describes the first case, to our knowledge, of autoimmune hyperphosphatemic tumoral calcinosis with pathogenic autoantibodies targeting FGF23. Identification of this pathophysiology extends the etiologic spectrum of hyperphosphatemic tumoral calcinosis and suggests that immunomodulatory therapy may be an effective treatment.

Hyperphosphatemic familial tumoral calcinosis secondary to fibroblast growth factor 23 (FGF23) mutation: a report of two affected families and review of the literature.

Hyperphosphatemic familial tumoral calcinosis (HFTC), secondary to fibroblast growth factor 23 (FGF23) gene mutation, is a rare genetic disorder characterized by recurrent calcified masses. We describe young Lebanese cousins presenting with HFTC, based on a retrospective chart review and a prospective case study. In addition, we present a comprehensive review on the topic, based on a literature search conducted in PubMed and Google Scholar, in 2014 and updated in December 2017. While the patients had the same previously reported FGF23 gene mutation (homozygous c.G367T variant in exon 3 leading to a missense mutation), they presented with variable severity and age of disease onset (at 4 years in patient 1 and at 23 years in patient 2). A review of the literature revealed several potential patho-physiologic pathways of HFTC clinical manifestations, some of which may be independent of hyperphosphatemia. Most available treatment options aim at reducing serum phosphate level, by stimulating renal excretion or by inhibiting intestinal absorption. HFTC is a challenging disease. While the available medical treatment has a limited and inconsistent effect on disease symptomatology, surgical resection of calcified masses remains the last resort. Research is needed to determine the safety and efficacy of FGF23 replacement or molecular therapy, targeting the specific genetic aberration. Hyperphosphatemic familial tumoral calcinosis is a rare genetic disorder characterized by recurrent calcified masses, in addition to other visceral, skeletal, and vascular manifestations. It remains a very challenging disease.

Hiperostosis cortical infantil: reporte de caso / Infantile cortical hyperostosis: Case report

La hiperostosis cortical infantil, o enfermedad de Caffey-Silverman, es una entidad clínica caracterizada por neoformación ósea perióstica secundaria a un proceso inflamatorio agudo. De baja frecuencia, su curso clínico es generalmente autolimitado y de excelente pronóstico. Objetivo: Presentar el caso de un lactante portador de un cuadro clínico compatible con una hiperostosis cortical infantil. Caso clínico: Lactante varón, 4 meses de edad, previamente sano, que consultó por presentar irritabilidad, llanto, aumento de volumen en la cara, los brazos y las piernas. Se observó aumento de volumen al nivel de la rama mandibular bilateral, simétrica, sensible, sin cambios en la coloración, la temperatura o la textura, hasta la región preauricular. El estudio bioquímico fue normal, y el estudio radiológico mostró reacción perióstica (periostitis e hiperostosis) al nivel de la rama mandibular, el fémur izquierdo, la tibia y el radio bilateral. Se manejó con antipiréticos, antiinflamatorios y analgésicos, y estuvo en observación en el servicio de urgencias durante 6 h, donde se decidió su egreso y el manejo ambulatorio. La sintomatología cedió por completo entre 4 y 6 semanas después del alta. Conclusión: La hiperostosis cortical es una colagenopatía que debe ser considerada como diagnóstico diferencial en cuadros agudos de inflamación ósea, irritabilidad y fiebre. Es indispensable conocerla para sospecharla y la correlación clínico-radiológica es notable.

Infantile Cortical Hyperostosis, or Caffey-Silverman disease, is a rare condition characterised by generalised bone proliferation mediated by an acute inflammatory process. Diagnosis can be made through clinical evaluation and X-ray studies. The course is generally self-limiting and prognosis is excellent. Objective: To present the case of a 4-month child with clinical and radiological symptoms compatible with Infantile Cortical Hyperostosis. Case report: A 4-month old male who presented with crying and irritability associated with swelling of the face, arms and legs was admitted to the Emergency Room of National Institute of Pediatrics. Bilateral mandibular swelling extending to periauricular region was observed, with no signs of inflammation. X-ray studies showed a periosteal reaction in the jaw, left femur and tibia, and radius bilateral. Clinical observation combined with analgesics and antipyretics was the only medical intervention. Four to six months after discharge from hospital, the symptoms disappeared, confirming the good prognosis of this condition. Conclusion: Infantile cortical hyperostosis is a collagenopathy, which must be considered as a differential diagnosis in acute bone inflammatory processes, irritability and fever. It is important to understand and identify this disease and clinical-radiological correlation is remarkable.

Molecular Characterization of Three Canine Models of Human Rare Bone Diseases: Caffey, van den Ende-Gupta, and Raine Syndromes.

One to two percent of all children are born with a developmental disorder requiring pediatric hospital admissions. For many such syndromes, the molecular pathogenesis remains poorly characterized. Parallel developmental disorders in other species could provide complementary models for human rare diseases by uncovering new candidate genes, improving the understanding of the molecular mechanisms and opening possibilities for therapeutic trials. We performed various experiments, e.g. combined genome-wide association and next generation sequencing, to investigate the clinico-pathological features and genetic causes of three developmental syndromes in dogs, including craniomandibular osteopathy (CMO), a previously undescribed skeletal syndrome, and dental hypomineralization, for which we identified pathogenic variants in the canine SLC37A2 (truncating splicing enhancer variant), SCARF2 (truncating 2-bp deletion) and FAM20C (missense variant) genes, respectively. CMO is a clinical equivalent to an infantile cortical hyperostosis (Caffey disease), for which SLC37A2 is a new candidate gene. SLC37A2 is a poorly characterized member of a glucose-phosphate transporter family without previous disease associations. It is expressed in many tissues, including cells of the macrophage lineage, e.g. osteoclasts, and suggests a disease mechanism, in which an impaired glucose homeostasis in osteoclasts compromises their function in the developing bone, leading to hyperostosis. Mutations in SCARF2 and FAM20C have been associated with the human van den Ende-Gupta and Raine syndromes that include numerous features similar to the affected dogs. Given the growing interest in the molecular characterization and treatment of human rare diseases, our study presents three novel physiologically relevant models for further research and therapy approaches, while providing the molecular identity for the canine conditions.

Phenotypic and Genotypic Characterization and Treatment of a Cohort With Familial Tumoral Calcinosis/Hyperostosis-Hyperphosphatemia Syndrome.

Familial tumoral calcinosis (FTC)/hyperostosis-hyperphosphatemia syndrome (HHS) is a rare disorder caused by mutations in the genes encoding fibroblast growth factor-23 (FGF23), N-acetylgalactosaminyltransferase 3 (GALNT3), or KLOTHO. The result is functional deficiency of, or resistance to, intact FGF23 (iFGF23), causing hyperphosphatemia, increased renal tubular reabsorption of phosphorus (TRP), elevated or inappropriately normal 1,25-dihydroxyvitamin D3 (1,25D), ectopic calcifications, and/or diaphyseal hyperostosis. Eight subjects with FTC/HHS were studied and treated. Clinical manifestations varied, even within families, ranging from asymptomatic to large, disabling calcifications. All subjects had hyperphosphatemia, increased TRP, and elevated or inappropriately normal 1,25D. C-terminal FGF23 was markedly elevated whereas iFGF23 was comparatively low, consistent with increased FGF23 cleavage. Radiographs ranged from diaphyseal hyperostosis to massive calcification. Two subjects with severe calcifications also had overwhelming systemic inflammation and elevated C-reactive protein (CRP). GALNT3 mutations were identified in seven subjects; no causative mutation was found in the eighth. Biopsies from four subjects showed ectopic calcification and chronic inflammation, with areas of heterotopic ossification observed in one subject. Treatment with low phosphate diet, phosphate binders, and phosphaturia-inducing therapies was prescribed with variable response. One subject experienced complete resolution of a calcific mass after 13 months of medical treatment. In the two subjects with systemic inflammation, interleukin-1 (IL-1) antagonists significantly decreased CRP levels with resolution of calcinosis cutis and perilesional inflammation in one subject and improvement of overall well-being in both subjects. This cohort expands the phenotype and genotype of FTC/HHS and demonstrates the range of clinical manifestations despite similar biochemical profiles and genetic mutations. Overwhelming systemic inflammation has not been described previously in FTC/HHS; the response to IL-1 antagonists suggests that anti-inflammatory drugs may be useful adjuvants. In addition, this is the first description of heterotopic ossification reported in FTC/HHS, possibly mediated by the adjacent inflammation. © 2016 American Society for Bone and Mineral Research.

[Infantile cortical hyperostosis: Case report]. / Hiperostosis cortical infantil: reporte de caso.

Infantile Cortical Hyperostosis, or Caffey-Silverman disease, is a rare condition characterised by generalised bone proliferation mediated by an acute inflammatory process. Diagnosis can be made through clinical evaluation and X-ray studies. The course is generally self-limiting and prognosis is excellent. OBJECTIVE: To present the case of a 4-month child with clinical and radiological symptoms compatible with Infantile Cortical Hyperostosis. CASE REPORT: A 4-month old male who presented with crying and irritability associated with swelling of the face, arms and legs was admitted to the Emergency Room of National Institute of Pediatrics. Bilateral mandibular swelling extending to periauricular region was observed, with no signs of inflammation. X-ray studies showed a periosteal reaction in the jaw, left femur and tibia, and radius bilateral. Clinical observation combined with analgesics and antipyretics was the only medical intervention. Four to six months after discharge from hospital, the symptoms disappeared, confirming the good prognosis of this condition. CONCLUSION: Infantile cortical hyperostosis is a collagenopathy, which must be considered as a differential diagnosis in acute bone inflammatory processes, irritability and fever. It is important to understand and identify this disease and clinical-radiological correlation is remarkable.

[Kenny-Caffey syndrome and its related syndromes].

Kenny-Caffey syndrome (KCS) is a very rare dysmorphologic syndrome characterized by proportionate short stature, cortical thickening and medullary stenosis of tubular bones, delayed closure of anterior fontanelle, eye abnormalities, and hypoparathyroidism. Two types of KCS were known: the autosomal recessive form (KCS type 1), which is caused by mutations of the TBCE gene, and the autosomal dominant form (KCS type 2), which is caused by mutations of the FAM111A gene. TBCE mutation also causes hypoparathyroidism-retardation-dysmorphism syndrome, and FAM111A mutation also causes gracile bone dysplasia. These two diseases can be called as KCS-related syndromes. In this article, we review the clinical manifestations of KCS and discuss its related syndromes.

Hyperphosphatemic familial tumoral calcinosis: odontostomatologic management and pathological features.

BACKGROUND: Hyperphosphatemic familial tumoral calcinosis (HFTC) is to a rare autosomal recessive disorder characterized by cutaneous and sub-cutaneous calcified masses, usually adjacent to large joints. The aim of the current study was to report on the clinico-pathological features of a patient with HFCT, with emphasis on alterations in the jawbones and teeth and the subsequent therapeutic interventions. CASE REPORT: A 13-year-old male patient with HFTC diagnosis came to our attention for dental anomalies and maxillary and mandibular hypoplasia. OPT highlighted multiple impacted teeth, short and bulbous teeth, and pulp chamber and canal obliterations. Lateral cephalometric radiograms pointed out retrusion of both jaws, skeletal class II malocclusion, and deep-bite. He underwent orthopedic, orthodontic, conservative, and surgical treatments, allowing the correction of maxillo-facial and dental abnormalities and dysmorphisms without adverse effects. The surgical samples were sent for conventional and confocal laser scanning microscope (CLSM) histopathological examination, which highlighted several metaplastic micro- and macro-calcifications in the soft tissues, and typical islands of homogenous, non-tubular, dentino-osteoid calcified structures in dentinal tissues. CONCLUSIONS: The management of maxillo-facial abnormalities in patients affected by HFTC is very difficult and, requires a combined therapeutic approach. To date, very few indications have been published in the literature.

Caffey disease: new perspectives on old questions.

The autosomal dominant form of Caffey disease is a largely self-limiting infantile bone disorder characterized by acute inflammation of soft tissues and localized thickening of the underlying bone cortex. It is caused by a recurrent arginine-to-cysteine substitution (R836C) in the α1(I) chain of type I collagen. However, the functional link between this mutation and the underlying pathogenetic mechanisms still remains elusive. Importantly, it remains to be established as to how a point-mutation in type I collagen leads to a cascade of inflammatory events and spatio-temporally limited hyperostotic bone lesions, and how structural and inflammatory components contribute to the different organ-specific manifestations in Caffey disease. In this review we attempt to shed light on these questions based on the current understanding of other mutations in type I collagen, their role in perturbing collagen biogenesis, and consequent effects on cell-cell and cell-matrix interactions.

Mineralization/anti-mineralization networks in the skin and vascular connective tissues.

Ectopic mineralization has been linked to several common clinical conditions with considerable morbidity and mortality. The mineralization processes, both metastatic and dystrophic, affect the skin and vascular connective tissues. There are several contributing metabolic and environmental factors that make uncovering of the precise pathomechanisms of these acquired disorders exceedingly difficult. Several relatively rare heritable disorders share phenotypic manifestations similar to those in common conditions, and, consequently, they serve as genetically controlled model systems to study the details of the mineralization process in peripheral tissues. This overview will highlight diseases with mineral deposition in the skin and vascular connective tissues, as exemplified by familial tumoral calcinosis, pseudoxanthoma elasticum, generalized arterial calcification of infancy, and arterial calcification due to CD73 deficiency. These diseases, and their corresponding mouse models, provide insight into the pathomechanisms of soft tissue mineralization and point to the existence of intricate mineralization/anti-mineralization networks in these tissues. This information is critical for understanding the pathomechanistic details of different mineralization disorders, and it has provided the perspective to develop pharmacological approaches to counteract the consequences of ectopic mineralization.