A GALNT3 mutation causing Hyperphosphatemic familial Tumoral calcinosis

Abstract

AimHyperphosphatemic Familial Tumoral Calcinosis (HFTC) is an autosomal recessive disorder. This study investigates the etiology of HFTC in offspring from consanguineous parents. Methods: Clinical assessment, imaging, and direct sequencing were utilized to elucidate the condition. Previously reported cases were also reviewed. Result: We identified a consanguineous Chinese family with HFTC caused by an interesting homozygous G to A substitution in GALNT3 (c.1626 + 1G > A). The parents were carriers. Conclusion: This study represents the first report of HFTC in a consanguineous Chinese family due to an interesting GALNT3 mutation. We reviewed known GALNT3 variants and associated clinical features of calcification disorders. The phenotypic difference between homozygous and complex heterozygous mutations is not clinically significant. Gene mutations affect the function of proteins mainly by affecting their binding to polyvalent ligands.

Keywords

• HFTC
• GALNT3
• GALNT3 mutation
• Ectopic calcification
• Metabolic bone disease
• Phosphate