Analysis of the CTAGE5 P521A variation with the risk of familial idiopathic basal ganglia calcification in an Iranian population.

Familial idiopathic basal ganglia calcification (IBGC) is a rare neurodegenerative syndrome with an autosomal dominant pattern of inheritance which is characterized by deposition of calcium in the basal ganglia and other brain regions. Linkage studies demonstrated its genetic heterogeneity; however, the responsible genes are unknown. Recently, a heterozygous variation (C>G, P521A) at exon 20 of the human cutaneous T cell lymphoma-associated antigen 5 (CTAGE5) gene was found in all patients of the affected large American family linked to IBGC1 (14q11.2-21.3). However, no carrier was detected in the two affected Brazilian families. This study was performed to investigate whether the CTAGE5 P521A variation is associated with the IBGC in an affected Iranian family. Genotyping of the CTAGE5 P521A variation was determined using PCR-RFLP. Totally, 22 members of an affected Iranian family as well as 100 normal people as control group were screened. All the samples including 22 members of the affected family as well as all control people had normal CC genotype and no GC carrier was found. Our result is similar to a Brazilian study but contrary to an American report, strengthening genetic heterogeneity of this syndrome. It seems that additional studies are necessary to confirm the pathogenicity of this rare mutation.