Tumoral calcinosis due to GALNT3 C.516-2A >T mutation in a black African family.

Familial Tumoral Calcinosis (FTC) is a rare autosomal recessive disorder of the phosphocalcic metabolism caused by mutations in the FGF23 or GALNT3 genes. We have identified a Beninese family in which two brothers present FTC caused by a homozygous A>T transversion at the acceptor splice site in intron 1 of GALNT3 gene. We report on the clinical, biochemical, histopathological and molecular spectrum of the disorder in this family. The particularly severe phenotype, the amelogenesis imperfecta, and the carbapatite deposit observed in these patients, seem to be characteristic of our observations.