Basal ganglia calcification is a nonspecific finding that can occur in the context of certain infectious, metabolic, and genetic syndromes. It may simply constitute a benign incidental finding (around 1% of CT scans performed for other reasons in people over 60 years of age), the sequel of a connatal infection, but there is an associated clinical picture, not explained by other causes and particularly in the context positive family history, the possibility of a genetic study should be considered.
There are two conditions that we have considered for addressing this panel:
- In childhood, Aicardi-Goutières syndrome (AGS) is an early-onset encephalopathy that presents with cerebral atrophy, leukodystrophy, and characteristically calcifications of the basal ganglia and elevated levels of interferon in the CSF. There are several genes described (RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, TREX1, ADAR, and IFIH1), with which a diagnostic yield of 90-95% is achieved. of suspected AGS cases (Crowet al., 2015). Since the original description (Aicardi and Goutières, 1984), the phenotypic spectrum has been expanding, which should be taken into account, particularly in later forms of presentation.
- In adults around the 3rd-5th decade of life, one might think of idiopathic calcification of the basal ganglia (Fahr’s disease): an autosomal dominant condition, usually of familial onset, characterized by symmetrical calcification in the basal ganglia and other regions of the brain. The symptoms can range from asymptomatic stages to a wide spectrum of neuropsychiatric symptoms. The genes involved to date are SLC20A2, XPR1, PDGFB, and PDGFRB. More recently, the involvement of 2 additional genes, PCDH12 and MYORG, in autosomal recessive transmission, has been described.
