From OMIM
Familial idiopathic basal ganglia calcification is an autosomal dominant condition characterized by symmetric calcification in the basal ganglia and other brain regions. Patients with calcifications can either be asymptomatic or show a wide spectrum of neuropsychiatric symptoms, including parkinsonism, dystonia, tremor, ataxia, dementia, psychosis, seizures, and chronic headache. Serum levels of calcium, phosphate, alkaline phosphatase, and parathyroid hormone are normal. The typical age at clinical onset is between 30 and 50 years (summary by Wang et al., 2012). Calcification of the basal ganglia is a nonspecific finding in many medical conditions, including infectious, metabolic, and genetic syndromes. In addition, calcification of the basal ganglia is observed as an incidental finding in approximately 0.7 to 1.2% of CT scans (Koller et al., 1979; Harrington et al., 1981; Forstl et al., 1992). These incidental calcifications are usually benign and have no clear etiology, especially in patients over 60 years of age (Geschwind et al., 1999). Forstl et al. (1992) found no increased risk for dementia, cerebral infarction, seizures, alcoholism, vertigo, or headache in 166 patients with calcification of the basal ganglia compared to 622 individuals without calcification. Genetic Heterogeneity of Idiopathic Basal Ganglia Calcification See IBGC4 (615007), caused by mutation in the PDGFRB gene (173410) on 5q32; IBGC5 (615483), caused by mutation in the PDGFB gene (190040) on 22q13; IBGC6 (616413), caused by mutation in the XPR1 gene (605237) on 1q25; IBGC7 (618317), caused by mutation in the MYORG gene (618255) on 9p13; and IBGC8 (618824), caused by mutation in the JAM2 gene (606870) on 21q21. See 114100 for a childhood-onset form of idiopathic basal ganglia calcification. The symbol IBGC3 previously referred to the locus on chromosome 8p11 that includes the SLC20A2 gene (Dai et al., 2010). However, the family that originally defined the putative IBGC1 locus on chromosome 14q (Geschwind et al., 1999) was later found to carry a pathogenic mutation in the SLC20A2 gene (Hsu et al., 2013), and the IBGC locus on chromosome 14q has not been replicated (Oliveira et al., 2004; Hsu et al., 2013). Thus, the symbol IBGC1 now refers to the disorder caused by mutation in the SLC20A2 gene on chromosome 8p11 and the symbol IBGC3 is no longer used. In addition, the symbol IBGC2 was previously used for a form of IBGC erroneously mapped to 2q37; the family in which this linkage was reported by Volpato et al. (2009) was later found by Grutz et al. (2016) to have a mutation in the SLC20A2 gene and thus to have IBGC1.  http://www.omim.org/entry/213600

From MedlinePlus Genetics
The severity of primary familial brain calcification varies among affected individuals; some people have no symptoms related to the condition, whereas others have significant movement and psychiatric problems.

Psychiatric and behavioral problems occur in 20 to 30 percent of people with primary familial brain calcification. These problems can include difficulty concentrating, memory loss, changes in personality, a distorted view of reality (psychosis), and decline in intellectual function (dementia). Affected individuals may also have difficulty swallowing (dysphagia), impaired speech, headache, episodes of extreme dizziness (vertigo), seizures, or urinary problems.

The main signs and symptoms of primary familial brain calcification are movement disorders and psychiatric or behavioral problems. These difficulties usually begin in mid-adulthood, and worsen over time. Most affected individuals have a group of movement abnormalities called parkinsonism, which include unusually slow movement (bradykinesia), muscle rigidity, and tremors. Other movement problems common in people with primary familial brain calcification include involuntary tensing of various muscles (dystonia), uncontrollable movements of the limbs (choreoathetosis), and an unsteady walking style (gait).

Primary familial brain calcification is a condition characterized by abnormal deposits of calcium (calcification) in blood vessels within the brain. These calcium deposits are visible only on medical imaging and typically occur in the basal ganglia, which are structures deep within the brain that help start and control movement of the body. Other brain regions may also be affected.  https://medlineplus.gov/genetics/condition/primary-familial-brain-calcification