J Pediatr Genet 2023; 12(04): 280-287
DOI: 10.1055/s-0041-1741522
Original Article

Recurrent Bilateral Lower Motor Neuron Type of Facial Palsy with Hearing Impairment: Hyperphosphatemic Familial Tumoral Calcinosis

1   Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
,
Anusha Raj
1   Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
,
Dhananjaya K. Vamyanmane
2   Department of Pediatric Radiology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
,
Vani H. Nagarajappa
3   Department of Pediatric Endocrinology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
,
Sahana M. Srinivas
4   Department of Pediatric Dermatology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
,
Rajalakshmi Tirumale
5   Department of Pathology, St John's Medical College, Bangalore, Karnataka, India
,
Jaya Ranganath
6   Department of Pediatric Cardiology, Sri Jayadeva Institute of Cardiology, Bangalore, Karnataka, India
,
Chandan Gaddehosur
7   Department of Pedodontics, V.S. Dental College and Hospital, Bangalore, Karnataka, India
,
Gurudatta B. Vishwanathan
8   Center for Human Genetics, Biotech Park, Electronic City Phase I, Bengaluru, Karnataka, India
› Author Affiliations

Funding None.
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Abstract

Hyperphosphatemic familial tumoral calcinosis (HFTC) presents with varied neurological manifestations that have been reported in the literature like facial palsy, vision and hearing impairment, stroke, and headache. In this article, we reported a 12-year-old girl child patient with recurrent facial weakness with bilateral hearing impairment and multiple ulcerative lesions on lower limbs and elbows. On examination, she had lower motor neuron (LMN) facial palsy with conductive hearing loss. The investigations showed hyperphosphatemia (9.3 mg/dL) with normal serum calcium (10.4 mg/dL), alkaline phosphatase (147.9 U/L), parathyroid hormone (23.12 pg/mL), and renal function tests. Elevated serum calcium and phosphorus product (96.72 mg2/mL2) and elevated renal tubular reabsorption of phosphate (TMPxGFR) value (9.16) were noted. Skeletal survey showed hyperostosis in the long bone diaphysis, vertebrae, ribs, pelvic bone, skull, and facial bones with narrowing of cranial ostium, characteristically without any peri-articular soft tissue calcifications. An angiogram showed multiple intravascular calcifications. She was managed with a low-phosphate diet, sevelamer, niacinamide, acetazolamide, sucroferric oxyhydroxide to lower serum phosphate level, and topical sodium thiosulfate ectopic cutaneous calcification. Exome sequencing showed novel homozygous inframe deletion of ACG in FGF23 gene exon 3 at c.374_376 delins position (p. Asp125del) in the proband and a mutation in the heterozygous state in the mother and elder sibling, thus confirming a molecular diagnosis of HFTC. Our case had a unique neurological presentation of recurrent bilateral lower motor nerve facial palsy, hearing loss, multiple ectopic cutaneous calcifications without peri-articular deposits, multiple intravascular, intracranial, and vertebral endplate calcification, which has not been reported earlier. The proband showed a novel pathogenic variant suggesting an expanding phenotype of HFTC.

Authors' Contributions

V.K. supervised, guided, and reviewed the manuscript. A.R. was involved in the management of the child and the preparation of manuscript. D.V. was involved in the collection of data and the preparation of manuscript. V.H. was involved in the collection of data and the preparation of manuscript. S.S. provided valuable inputs in the management of this child. R.T. was involved in the collection of data and the preparation of manuscript. J.R. was involved in the collection of data and the preparation of manuscript. C.G. was involved in the collection of data and the preparation of manuscript. G.D. was involved in the molecular genetic analysis and the preparation of manuscript.




Publication History

Received: 24 April 2021

Accepted: 06 December 2021

Article published online:
07 January 2022

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