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.

Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease).

BACKGROUND: Infantile cortical hyperostosis (ICH)/Caffey disease is an inflammatory collagenopathy of infancy, manifested by subperiosteal bone hyperplasia. Genetically, ICH was linked with heterozygosity for an R836C mutation in the COL1A1 gene. Although an autosomal-recessive trait is also suspected, it has not been proven thus far. METHODS: A case of an infant male born to consanguineous parents is reported, presenting with classical findings, course, and clinical outcome of ICH. Whole-exome sequencing (WES) was performed in order to identify a possible underlying genetic defect. RESULTS: WES analysis revealed a novel homozygous nonsense mutation in lysine 2 of fetuin-A, encoded by the ALPHA-2-HS-GLYCOPROTEIN (AHSG) gene (c.A4T; p.K2X). Fetuin-A is an important regulator of bone remodeling and an inhibitor of ectopic mineralization. By enzyme-linked immunosorbent assay (ELISA), we show a complete deficiency of this protein in the patient's serum, compared to controls. CONCLUSION: A novel homozygous nonsense mutation in AHSG gene has been found in ICH patient with a typical phenotype, resulting in fetuin-A deficiency. This finding postulates an autosomal-recessive mode of inheritance in ICH, which, unlike the autosomal-dominant inheritance associated with COL1A1, is associated with AHSG and fetuin-A deficiency.

Severe vascular calcification and tumoral calcinosis in a family with hyperphosphatemia: a fibroblast growth factor 23 mutation identified by exome sequencing.

BACKGROUND: Tumoral calcinosis is an autosomal recessive disorder characterized by ectopic calcification and hyperphosphatemia. METHODS: We describe a family with tumoral calcinosis requiring amputations. The predominant metabolic anomaly identified in three affected family members was hyperphosphatemia. Biochemical and phenotypic analysis of 13 kindred members, together with exome analysis of 6 members, was performed. RESULTS: We identified a novel Q67K mutation in fibroblast growth factor 23 (FGF23), segregating with a null (deletion) allele on the other FGF23 homologue in three affected members. Affected siblings had high circulating plasma C-terminal FGF23 levels, but undetectable intact FGF23 or N-terminal FGF23, leading to loss of FGF23 function. CONCLUSIONS: This suggests that in human, as in experimental models, severe prolonged hyperphosphatemia may be sufficient to produce bone differentiation proteins in vascular cells, and vascular calcification severe enough to require amputation. Genetic modifiers may contribute to the phenotypic variation within and between families.

Structural and molecular imaging-based characterization of soft tissue and vascular calcification in hyperphosphatemic familial tumoral calcinosis.

Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare disorder caused by deficient FGF23 signaling and resultant ectopic calcification. Here, we systematically characterized and quantified macro- and micro-calcification in a HFTC cohort using CT and 18F-sodium fluoride PET/CT (18F-NaF PET/CT). Fourier-transform infrared (FTIR) spectroscopy was performed on 4 phenotypically different calcifications from a patient with HFTC, showing the dominant component to be hydroxyapatite. Eleven patients with HFTC were studied with CT and/or 18F-NaF PET/CT. Qualitative review was done to describe the spectrum of imaging findings on both modalities. CT-based measures of volume (eg, total calcific burden and lesion volume) and density (Hounsfield units) were quantified and compared to PET-based measures of mineralization activity (eg, mean standardized uptake values-SUVs). Microcalcification scores were calculated for the vasculature of 6 patients using 18F-NaF PET/CT and visualized on a standardized vascular atlas. Ectopic calcifications were present in 82% of patients, predominantly near joints and the distal extremities. Considerable heterogeneity was observed in total calcific burden per patient (823.0 ± 670.1 cm3, n = 9) and lesion volume (282.5 ± 414.8 cm3, n = 27). The largest lesions were found at the hips and shoulders. 18F-NaF PET offered the ability to differentiate active vs quiescent calcifications. Calcifications were also noted in multiple anatomic locations, including brain parenchyma (50%). Vascular calcification was seen in the abdominal aorta, carotid, and coronaries in 50%, 73%, and 50%, respectively. 18F-NaF-avid, but CT-negative calcification was seen in a 17-year-old patient, implicating early onset vascular calcification. This first systematic assessment of calcifications in a cohort of patients with HFTC has identified the early onset, prevalence, and extent of calcification. It supports 18F-NaF PET/CT as a clinical tool for distinguishing between active and inactive calcification, informing disease progression, and quantification of ectopic and vascular disease burden.

Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare disorder in which patients develop sometimes large debilitating calcifications of soft tissues and blood vessels. It is caused by deficient fibroblast growth factor-23 that leads to high phosphate levels, which contributes to the calcifications. The calcifications and manifestations of this disorder have not been well characterized. We determined the mineral composition of the calcifications to be hydroxyapatite. Capitalizing on the fact fluoride can be integrated into hydroxyapatite, we used radiolabeled sodium fluoride PET/CT scans (18F-NaF PET/CT) to characterize and quantify the calcifications in 11 patients. Eighty-two percent of the patients had calcifications, with the largest located at the hips and shoulders. Micro-calcifications were found in the blood vessels of most patients, including children. The technique also enabled us to differentiate between active vs stable calcifications. This first systematic assessment of calcifications in patients with HFTC showed the utility of 18F-NaF PET/CT as a tool to identify and quantify calcifications, as well as distinguish between active and stable calcifications. This approach will inform disease progression and may prove useful for measuring response to treatment.

Case Report of Worth Syndrome and Chiari I Malformation: Unusual Association and Surgical Treatment.

BACKGROUND: Worth syndrome or autosomal dominant endosteal hyperostosis (ADEH) is an extremely rare genetic disease involving increased bone density. To the author's knowledge, this is the second case report of a family with neurologic involvement associated with this condition along with its surgical treatment. The most effective treatment for clinically significant neurologic symptoms in this scenario is currently unknown, and there is sparse experience on surgical treatment for this condition reported in the literature. Therefore we aim to make a contribution to the identification of a standard and consistently successful surgical management. CASE DESCRIPTION: Two patients, mother (Patient 1) and daughter (Patient 2), were diagnosed with Worth syndrome. Both presented with the typical facial characteristics described for ADEH. Interestingly, Patient 1 presented the novel mutation in the LRP5 gene that is associated with different conditions involving increased bone density. Although neurologic symptoms are infrequent in ADEH, both referred chronic headache, nausea, and vomiting. Neuroimaging showed an increased cranial bone density and Chiari I malformation. The patients underwent a midline suboccipital craniectomy with excision of the posterior arch of C1 and duroplasty. However, due to a symptomatic recurrence 5 years after surgery, Patient 1 was reoperated on. We extended the craniectomy and also carried out a C2 laminectomy. CONCLUSION: After surgical interventions, patients' neurologic symptoms were successfully resolved. This report shows that posterior fossa decompression including duroplasty may be a valid treatment option in case of neurologic involvement.

An Unusual Cause of Pseudopapillary Oedema: Hyperphosphatemic Hyperostosis Syndrome.

For the first time, we report hyperphosphatemic hyperostosis syndrome as a cause for pseudopapillary oedema in a pediatric case. Clinical findings are presented and discussed with tomographic evaluation (optical coherence tomography and Heidelberg retinal tomography) of optic discs, visual-evoked potentials, and visual fields.

Root anomalies and dentin dysplasia in autosomal recessive hyperphosphatemic familial tumoral calcinosis (HFTC).

Hyperphosphatemic familial tumoral calcinosis (HFTC, OMIM #211900) is an autosomal recessive metabolic disorder characterized by hyperphosphatemia, tooth root defects, and the progressive deposition of calcium phosphate crystals in periarticular spaces, soft tissues, and sometimes bone.(1) In this HFTC case report, we document the dental phenotype associated with a homozygous missense mutation (g.29077 C>T; c.484 C>T; p.Arg162*) in GALNT3 (OMIM 6017563), a gene encoding UDP-GalNAc transferase 3 that catalyzes the first step of O-linked oligosaccharide biosynthesis in the Golgi. The medical and dental pathology is believed to be caused primarily by high serum phosphate levels (hyperphosphatemia), which, in turn, is caused by failure of GALNT3 to glycosylate the phosphate regulator protein FGF23, impairing its ability inhibit reabsorption of filtered phosphate in the kidneys.

Recurrent Caffey's cortical hyperostosis and persistent deformity.

A boy, age 12 years, who had infantile cortical hyperostosis has continued to have occasional aches and new cortical thickenings in his arms and legs. His mandible is undergrown and his ribs have an abnormal slope. Recurrence of Caffey's cortical hyperostosis and persistent deformity have been observed in other children and young adults. Some unexplained cases of late cortical thickening and pain may be due to Caffey's disease.

Neurological involvement in Worth type endosteal hyperostosis: report of a family.

We present the first Australian family known with autosomal dominant endosteal hyperostosis affecting a mother and her 2 children. Neurological involvement comprising chronic intracranial hypertension and cranial nerve palsies were found in the mother; computerised tomography and magnetic resonance imaging of the head demonstrated symmetrical sclerosis of the cranial vault, narrow internal auditory meati and canals, inferior herniation of the cerebellar tonsils into the foramen magnum, and encroachment of occipital bone into the foramen magnum posteriorly. This is the fifth report of significant neurologic involvement in this condition and supports the view that severe forms of endosteal hyperostosis are not confined to the autosomal recessive variant, as individuals with the autosomal dominant form may also show progression with neurological involvement in adulthood.

Infantile cortical hyperostosis and facial nerve palsy.

Facial nerve palsy was diagnosed in a 13-month-old child with infantile cortical hyperostosis. Facial palsy preceded the roentgenographic evidence of mandibular hyperostosis but there was concurrent evidence of hyperostosis of multiple other bones. This case exemplifies the importance of maintaining a high index of suspicion for infantile cortical hyperostosis in infants and children presenting with facial swelling and facial nerve palsy.

Infantile cortical hyperostosis (Caffey's disease).

A case of infantile cortical hyperostosis (Caffey's disease) is presented with its usual clinical and radiological manifestations. The accompanying anaemia and thrombocytopenia as seen in our case is discussed. The possibility of autoantibodies secondary to an immunological defect is put forward to explain the cause of the anaemia and thrombocytopenia. This may be a new feature of the disease or a modification of the current concept.

[Familial facial paralysis. Generalised cortical hyperostosis (author's transl)]. / Paralysies faciales familiales. Hyperostose corticale généralisée.

Generalised cortical hyperostosis is a rare disease. In our own field it involves the lower jaw and the skull. Certain nerves, including the facial, may be compressed as a result. This condition behaves genetically in a recessive or dominant manner.

Different clinical picture in early and late onset cortical hyperostosis.

Six cases of Cortical Hyperostosis (C.H.) are presented. The clinical and laboratory features of the disease seem to be related to age at onset. In fact, our cases with a later onset (after the first year of life) are characterized by: a) a longer duration of the disease and a particularly high frequency of relapses; b) the absence of any sign of mandibular involvement; c) the presence of eosinophilia (700-1300/mm3). In two out of three cases having a later onset clinical and laboratory data suggest the hypotesis of a immunoallergic pathogenesis and particularly of cow's milk allergy. A review of the literature appears to confirm the differences between early and late onset forms of C.H. as for as the sites of skeletal involvement and the whole clinical course are concerned.

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.