A whole exome sequencing study of a Korean proband with idiopathic basal ganglia calcification and its daughter

Idiopathic basal ganglia calcification (IBGC) is characterized by brain calcification and a wide variety of neurological and psychiatric symptoms. In families displaying an autosomal dominant inheritance pattern, three causative genes have been identified: SLC20A2, PDGFRB, and very recently, PDGFB. While in clinical practice sporadic presentation of IBGC is frequent, well-documented reports of true sporadic occurrences are rare. We report a case of a 61-year-old woman who presented with depressive and dystonic symptoms revealing IBGC. Her 41-year-old daughter was healthy. In the proband, we identified 4 mutations in PDGFB, and 1 exonic mutation in SLC20A2, all of which were absent in the daughter. These mutations may result in a loss-of-function of PDGF-B or SLC20A2, which has been shown to cause IBGC in humans and disrupts the blood-brain barrier in mice resulting in brain calcification. Herein, we present the occurrence of a sporadic patient of IBGC and its causative mutations.