Considering that he was also presented with facial paralysis and nasal obstruction symptom, the diagnosis of craniometaphyseal dysplasia was suspected, and then was confirmed by the mutation analysis of ANKH of the proband and his family, which showed a de novo heterozygous mutation (C1124-1126delCCT) on exon 9.
We propose that this craniometaphyseal dysplasia mutation causes a loss of ANKH protein expression and activity in the plasma membrane as a result of aberrant intracellular protein trafficking.
Mutations in ANK result in two distinct calcification disorders: craniometaphyseal dysplasia and familial calcium pyrophosphate dihydrate deposition disease.