Hyperphosphatemic familial tumoral calcinosis is a rare autosomal recessive metabolic disorder characterized by the progressive deposition of basic calcium phosphate crystals in periarticular spaces, soft tissues, and sometimes bone (Chefetz et al., 2005). The biochemical hallmark of tumoral ... Hyperphosphatemic familial tumoral calcinosis is a rare autosomal recessive metabolic disorder characterized by the progressive deposition of basic calcium phosphate crystals in periarticular spaces, soft tissues, and sometimes bone (Chefetz et al., 2005). The biochemical hallmark of tumoral calcinosis is hyperphosphatemia caused by increased renal absorption of phosphate due to loss-of-function mutations in the FGF23 or GALNT3 gene. The term 'hyperostosis-hyperphosphatemia syndrome' is sometimes used when the disorder is characterized by involvement of the long bones associated with the radiographic findings of periosteal reaction and cortical hyperostosis. Although some have distinguished HHS from FTC by the presence of bone involvement and the absence of skin involvement (Frishberg et al., 2005), Ichikawa et al. (2010) concluded that the 2 entities represent a continuous spectrum of the same disease, best described as familial hyperphosphatemic tumoral calcinosis. HFTC is considered to be the clinical converse of autosomal dominant hypophosphatemic rickets (ADHR; 193100), an allelic disorder caused by gain-of-function mutations in the FGF23 gene and associated with hypophosphatemia and decreased renal phosphate absorption (Chefetz et al., 2005; Ichikawa et al., 2005).
Inclan et al. (1943) first gave the name 'tumoral calcinosis' to this condition, which was first described by Giard (1898) and then by Duret (1899). Ghormley (1942) reported multiple affected sibs.
Baldursson et al. (1969) observed ... Inclan et al. (1943) first gave the name 'tumoral calcinosis' to this condition, which was first described by Giard (1898) and then by Duret (1899). Ghormley (1942) reported multiple affected sibs. Baldursson et al. (1969) observed 4 affected sibs out of 12 in a black family. Hyperphosphatemia was documented as early as 21 months of age in one of them in whom tumoral calcinosis appeared at 4 years of age. A majority of the cases of this condition reported in the Anglo-American literature have been in blacks. Other familial cases were reported by Barton and Reeves (1961), Harkess and Peters (1967), and Wilber and Slatopolsky (1968). Dodge et al. (1965) described 3 sibs with heterotopic calcification, hyperphosphatemia, unresponsiveness to parathyroid hormone (PTH; 168450), and elevated renal tubular maximum for phosphate reabsorption. Stigmata of Albright hereditary osteodystrophy (AHO; see 103580) were not present. Some reported patients have had angioid streaks of the retina (see 607140) (McPhaul and Engel, 1961). This is consistent with the view that angioid streaks in pseudoxanthoma elasticum (PXE; 264800), sickle cell anemia (603903), and Paget disease (167250) are due to a brittle state of Bruch membrane produced by deposition of calcium, iron, and perhaps other cations. McPhaul and Engel (1961) reported affected brothers; in another family the proband's paternal grandfather was thought to have been affected and he was related to a family reported as PXE. From Beirut, Najjar et al. (1968) described 2 sibs with periarticular calcified masses, increased blood phosphorus, normal blood calcium, calcified vessels, and skin changes of PXE. The parents may have been related. An aunt was said to have heterotopic calcification. In a review of the radiologic findings of PXE, James et al. (1969) pictured a large calcified mass in the region of the elbow. The patient probably had the entity discussed here, which was called 'lipocalcinogranulomatose' by Teutschlaender (1935). Collard (1966) described 2 affected sisters in a sibship of 5. Calcification of the media was limited to arteries of the leg. The parents were normal and unrelated. Large calcified tophus-like nodules were situated around the joints of the fingers and toes. Although rheumatic symptoms had begun at age 20 in both, the sisters were in their 50s at the time of report. McClatchie and Bremner (1969) reported 26 cases from Kenya, where the condition has an unusually high frequency. Until the publication of the papers by Palmer (1966) and Thomson (1966), only 25 cases had been reported; they reported an additional 50 cases, mostly from Rhodesia, and mentioned seeing others in Nigeria and elsewhere. McClatchie and Bremner (1969) documented its occurrence in Uganda. Eight different Kenyan tribes were represented among 17 cases. Melhem et al. (1970) reported 2 unrelated children with episodic pain, swelling, and heat involving several bones of the extremities. One child had rib involvement. Radiographic examination showed periosteal reaction with hyperostosis that healed completely. Both children also had unexplained hyperphosphatemia. Osteomyelitis was ruled out in both cases. The authors suggested decreased renal tubular phosphate excretion and postulated a relation of the disorder to tumoral calcinosis. The patient reported by Goldbloom et al. (1966) as having periosteal periostosis may have also had the same disorder. Altman and Pomerance (1971) suggested that the patient they reported as having chronic polyostotic periostitis (Altman and Pomerance, 1961) may have had the same disorder, although that patient had only 1 documented episode of hyperphosphatemia. Hacihanefioglu (1978) reported 11 patients with tumoral calcinosis from Turkey. Balachandran et al. (1980) reported a family in which 7 of 15 sibs were affected. Goldfarb (1979) proposed an intrinsic defect in phosphate handling by the proximal renal tubule leading to increased reabsorption (Mitnick et al., 1980; Zerwekh et al., 1980). Involvement at the shoulders and buttocks was common. Mikati et al. (1981) described hyperphosphatemia associated with cortical hyperostosis in 6 children. All presented with recurrent episodes of swelling, pain, and tenderness of the long bones. Bone biopsies of 3 patients showed periosteal new bone formation. Serum phosphate levels were persistently elevated and serum calcium levels were normal. Prince et al. (1982) reported a sibship in which 7 of 13 sibs were affected. Serum phosphorus and 1,25-dihydroxycholecalciferol concentrations were increased and parathormone and 25-hydroxycholecalciferol concentrations decreased. Balance studies indicated increased gastrointestinal absorption and decreased renal excretion of calcium and phosphorus. The authors interpreted the data to indicate a hereditary abnormality of vitamin D metabolism, and suggested a defect in the normal feedback mechanism regulating the 25-hydroxy-1-alpha-hydroxylase enzyme. Clarke et al. (1984) studied 3 black children, including 2 sibs, who presented with recurrent pain and swelling of the legs. In addition to tumoral calcinosis and hyperphosphatemia, the children showed hyperostosis of diaphyses of long bones of the leg. The authors suggested that the syndrome of hyperostosis and hyperphosphatemia reported by Mikati et al. (1981) was fundamentally the same disorder despite the lack of tumoral calcinosis. Steinherz et al. (1985) observed 5 affected persons in 2 branches of a Druze Arab kindred. The patients presented with calcified deposits in or about the hips and knees beginning in childhood. The authors concluded that serum calcitriol levels do not decline in response to hyperphosphatemia and that hyperphosphatemia with elevated renotubular reabsorption of phosphate is a constant feature of this disorder. Low phosphorus diet and oral aluminum hydroxide gel did not lower serum phosphate levels or improve the calcified deposits. Lyles et al. (1985) studied a kindred previously reported by McPhaul and Engel (1961). Nine affected persons were identified in 4 generations, suggesting autosomal dominant inheritance. They used a unique dental lesion as a phenotypic marker. The teeth were hypoplastic but had fully developed enamel of normal color. Panoramic x-rays showed short, bulbous roots and almost complete obliteration of pulp cavities. Histologic studies showed that dentin in the radicular portion was deposited in swirls, and true pulp stones almost completely filled the pulp cavity. Elevated serum 1,25-dihydroxyvitamin D levels were found in all affected persons even though some did not show classic findings of tumoral calcinosis. Talab and Mallouh (1988) reported a 6-year-old girl with hyperostosis with hyperphosphatemia and noted that only 8 other cases had been previously reported. Clinical features included repeated attacks of bone pain and swelling, radiographic findings of periosteal reaction with cortical hyperostosis, and increased serum phosphorus with normal serum calcium and parathyroid hormone. Wilson et al. (1989) reported hyperphosphatemia associated with cortical hyperostosis and tumoral calcinosis in a 9-year-old black girl. There was no family history of the disorder. The report suggested a common pathogenesis between the 2 disorders. Slavin et al. (1993) reviewed the histopathologic and ultrastructural changes of tumoral calcinosis occurring in 7 affected sibs in a sibship of 15. This was the black family cared for in Galveston, Texas, over a period of 25 years and described in the medical literature a total of 9 times (i.e., Abbud et al., 1979; Balachandran et al., 1980; Baldursson et al., 1969; Chausmer et al., 1982; Clarke et al., 1984; Prince et al., 1982; Pursley et al., 1979; Viegas et al., 1985; Witcher et al., 1989). A useful summary of the clinical findings in the 7 patients was provided. In order of frequency for the site of first lesions, hips, elbows, shoulders, and scapulae led the list. All 7 patients has elevated serum phosphorus levels, and elevated levels of 1,25-vitamin D were detected in 3. One patient, who also had calcinosis cutis involving the antecubital, popliteal, and axillary areas and legs, died at age 19 of pulmonary hypertension. The other sibs varied in age from 20 to 40 years at the time of this report. Onset had varied from 22 months to 5 years of age. Three of the sibs were males. Slavin et al. (1993) concluded that tumoral calcinosis is triggered by bleeding, followed by aggregation of foamy histiocytes. These, in turn, are transformed, with participation of collagenolysis, into cystic cavities lined by osteoclast-like giant cells and histiocytes, resulting in lesions resembling adventitious bursae. Movement and friction resulting from the periarticular location of the lesions were thought to be key to this transformation. Narchi (1997) reported 2 sisters, born of consanguineous Saudi Arabian parents, with hyperostosis with hyperphosphatemia. Symptoms first appeared at ages 8 and 5 years, respectively. The older girl had warm and tender swelling of the lower third of the right tibia which resolved after several days, but recurred 5 and 6 months later in the opposite tibia. At age 11 years, she developed a 5-cm painless swelling in her right ankle. Radiographs showed multiple loculated, calcified densities which were proven to be tumoral calcinosis on histologic examination. Her younger sister had similar symptoms and radiographs showed a laminated onion skin appearance of a periosteal reaction with porotic and mild sclerotic changes of affected bones. A third unrelated girl had recurrent nonmigratory bilateral leg and arm pain since age 6 years. All 3 patients had increased serum phosphate, normal serum parathyroid hormone, normal serum vitamin D, and normal serum calcium. The co-occurrence of tumoral calcinosis in 1 child suggested a common pathogenic abnormality. Narchi (1997) noted that the recurrent episodes of bone pain and swelling were often misdiagnosed as osteomyelitis or septic arthritis. Adams et al. (1999) described a brother and sister of Iranian descent with histologically and radiologically proven tumoral calcinosis who presented with cerebral and peripheral aneurysms. The brother died of a ruptured subclavian artery aneurysm after surgical repair of brachial, iliofemoral, and celiac axis aneurysms. Magnetic resonance and catheter angiography in the sister demonstrated marked carotid dysplasia and a left ophthalmic segment aneurysm, not amenable to treatment. Ichikawa et al. (2006) reported a 25-year-old female patient who presented with eyelid calcification and biochemical features of tumoral calcinosis. There was no history of metastatic calcifications, mineral homeostasis abnormalities, or renal dysfunction. A radiologic skeletal survey showed no evidence of ectopic calcification or hyperostosis, but the patient was noted to have more calcified costal cartilage than typical for her age. While eyelid calcification had been described in tumoral calcinosis, the authors found no reports of the disorder presenting with isolated eyelid calcifications. Ichikawa et al. (2006) suggested that the finding of a patient with a milder phenotype carrying mutations in GALNT3 may indicate that tumoral calcinosis is more common than had been thought, with a range of milder phenotypes. That the condition could become more aggressive in the patient could not be excluded. Ichikawa et al. (2007) reported a 13-year-old girl with tumoral calcinosis due to a homozygous mutation in the KL gene (604824.0002). She developed mild swelling of the malleolus and thenar eminence without erythema or warmth. Laboratory studies showed increased serum phosphorus, active vitamin D, and FGF23. Radiographs showed osteopenia, patchy sclerosis in the hands, feet, long bones, and calvaria, intracranial calcifications, and calcifications of the dura and carotid arteries. On presentation, she also had increased serum calcium and parathyroid hormone, which was successfully treated by subtotal parathyroidectomy of hyperplastic glands. Biochemical studies showed inappropriate tubular reabsorption of phosphorus and defective FGF23 signaling due to the mutant KL protein. Ichikawa et al. (2010) reported 4 unrelated patients with hyperostosis-hyperphosphatemia syndrome/tumoral calcinosis. One child, born of first-degree cousins from Sri Lanka, presented with painful left lower leg swelling which was found to be hyperostosis of the tibia with circumferential endosteal and periosteal bone formation; there was evidence of infection. In the following 2 years, she developed periarticular calcified lesions in the elbow, consistent with tumoral calcinosis. Another patient was a Greek woman who presented at age 8 years with a tibial lesion involving the cortical and trabecular bones with subperiosteal ossification. At age 14, she had subcutaneous calcified lesions of the upper thigh and left hand. Laboratory studies in both patients showed increased serum phosphorus, normal calcium, and inappropriately low/normal 1,25-(OH)2D. There were also low levels of intact circulating FGF23 and increased C-terminal FGF23 fragments. Ichikawa et al. (2010) concluded that hyperostosis-hyperphosphatemia and tumoral calcinosis represent a continuous spectrum of the same disease caused by loss of GALNT3 function and low circulating intact FGF23.
Topaz et al. (2004) studied the large Druze and African American kindreds with familial tumoral calcinosis described by Steinherz et al. (1985) and Slavin et al. (1993), respectively. They mapped ... - Mutation in the GALNT3 Gene Topaz et al. (2004) studied the large Druze and African American kindreds with familial tumoral calcinosis described by Steinherz et al. (1985) and Slavin et al. (1993), respectively. They mapped the gene underlying the disorder to 2q24-q31 and demonstrated biallelic deleterious mutations in the GALNT3 gene (601756) in all affected individuals. The GALNT3 gene encodes a glycosyltransferase responsible for initiating mucin-type O-glycosylation, suggesting that defective posttranslational modification underlies this disorder. In affected members of a multigenerational family previously reported by McPhaul and Engel (1961) and Lyles et al. (1985), Ichikawa et al. (2005) identified biallelic mutations in the GALNT3 gene. The proband was compound heterozygous for 2 mutations (601756.0002 and 601756.0004), and the affected maternal great uncle was homozygous for 1 of the mutations (601756.0004). The family had originally been thought to show autosomal dominant inheritance, but biallelic mutations found in 2 generations demonstrated that the family had pseudoautosomal dominant inheritance. The findings confirmed that tumoral calcinosis is in fact an autosomal recessive trait. In 2 affected individuals from 2 Arab Moslem families with hyperostosis-hyperphosphatemia syndrome, Frishberg et al. (2005) identified homozygosity for a mutation in the GALNT3 gene (601756.0001). The mutation had previously been identified in a large Druze family with HFTC, indicating that the 2 disorders are allelic. Haplotype analysis confirmed a founder effect. Specktor et al. (2006) identified a homozygous mutation in the GALNT3 gene (601756.0005) in an HFTC patient of northern European origin, suggesting that the disease may have a wider geographic distribution than previously thought. The 32-year-old man had severe joint disease and dental anomalies. Ichikawa et al. (2006) reported a 25-year-old female patient who presented with eyelid calcification and biochemical features of tumoral calcinosis who was compound heterozygous for missense mutations in the GALNT3 gene (see 601756.0008). Ichikawa et al. (2010) reported 4 unrelated patients with hyperphosphatemia and recurrent calcified deposits in the bones or soft tissue associated with homozygous mutations in the GALNT3 gene (see, e.g. 601756.0011-601756.0012). One patient had a diagnosis of tumoral calcinosis, 1 hyperostosis-hyperphosphatemia syndrome, and 2 had diagnosis of both disorders. There were low levels of intact serum FGF23 and high levels of C-terminal FGF23 fragments in all 3 patients examined. Ichikawa et al. (2010) concluded that hyperostosis-hyperphosphatemia and tumoral calcinosis represent a continuous spectrum of the same disease caused by loss of GALNT3 function and low circulating intact FGF23. - Mutation in the FGF23 Gene In an individual with familial tumoral calcinosis in whom mutation in the GALNT3 gene had been excluded, Benet-Pages et al. (2005) identified a homozygous ser71-to-gly substitution in the FGF23 gene (S71G; 605380.0003). - Mutation in the KL Gene Ichikawa et al. (2007) reported a 13-year-old girl with tumoral calcinosis due to a homozygous mutation in the KL gene (604824.0002).