A Novel Mutation in FGF23 Causing Severe Manifestation of Hyperphosphataemic Familial Tumoral Calcinosis

Tania- Tofail^1, , Fariduddin M¹, Haq T¹, Selim S¹, Jahan S¹, Khan MA¹, Mustari M¹, Banu H¹, Datta NK², Islam MA², Hossain MS³ and Hasanat MA¹

¹Department of Endocrinology, BSMMU, Dhaka, Bangladesh

²Department of Orthopaedics, BSMMU, Dhaka, Bangladesh

³Department of Genetic Engineering, DU, Dhaka, Bangladesh

Cite this paper:
Tania- Tofail, Fariduddin M, Haq T, Selim S, Jahan S, Khan MA, Mustari M, Banu H, Datta NK, Islam MA, Hossain MS and Hasanat MA. A Novel Mutation in FGF23 Causing Severe Manifestation of Hyperphosphataemic Familial Tumoral Calcinosis. American Journal of Medical Case Reports. 2018; 6(5):99-102. doi: 10.12691/ajmcr-6-5-6

Abstract

We present a 16-year girl, second issue of a consanguineous couple presented with painless symmetrical bony swellings around hips for 3 years. She lost 25 kg weight due to profound anorexia in the first year of illness and developed secondary amenorrhea. Last 7 months she had repeated generalized tonic clonic seizure due to hypocalcaemia. The bony swellings were located in both gluteal regions and were 30x35 cm², hard and non tender. Mobility of hip joints were restricted. Except for severe wasting as a part of generalized cachexia other systemic examination was unremarkable. Investigations revealed anaemia (Hb-E trait), low albumin, low corrected calcium (during convulsions) otherwise normal, persistently high phosphate & vitamin-D level, normal iPTH & alkaline phosphatase (ALP), low serum ascorbic acid, normal ESR & CRP. X-ray & CT scan of pelvis showed large calcified mass in periarticular soft tissues. Biopsy confirmed presence of dystrophic calcification. Diagnosis of tumoral calcinosis was based on biochemical parameters, imaging and biopsy findings. A homozygous novel mutation in FGF homology domain: B-21 mutated from G to A at 232 in exon 2. As a result glutamic acid is replaced by lysine. Phosphate restricted diet and phosphate lowering agent improved biochemical paramaters. Surgical excision has been withheld. Contemporary manifestation of hFTC and Hb E trait; two disease of autosomal recessive inheritance in an individual makes it extremely rare. High index of suspicion is needed for early diagnosis and treatment.

Keywords:
Tumoral calcinosis Hyperphosphataemia FGF23

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