Identification and characterization of C3orf6, a new conserved human gene mapping to chromosome 3q28

This study reports the characterization of a novel human gene, chromosome 3 open reading frame 6 (C3orf6), mapped to chromosome 3q28, within the critical region of hereditary spastic paraplegia SPG14 locus. Based on computational "spliced" EST alignment and RT-PCR, two C3orf6 transcript variants were identified. The longer C3orf6 transcript contains a 1449-nt ORF, encoding a protein of 482 aa, while the shorter variant contains a 921-nt ORF, encoding for a protein of 306 aa. C3orf6 gene is organised on 12 exons and the shorter transcript comes from an alternative splicing event skipping exon 6. The two mRNA are differentially expressed in brain and in several other human tissues with a predominant level for the shorter transcript. By database analysis, EST assembling and RT-PCR, we identified the transcripts of mouse and rat C3orf6 orthologous genes. The involvement of C3orf6 in the spastic paraplegia was investigated by sequencing all coding exons and flanking sequences in the SPG14 family, excluding the presence of causative mutations.