This gene is part of a 500 kb inverted duplication on chromosome 5q13. This duplicated region contains at least four genes and repetitive elements which make it prone to rearrangements and deletions. The repetitiveness and complexity of the sequence have also caused difficulty in determining the organization of this genomic region. The duplication region includes both a telomeric and a centromeric copy of this gene. Deletions of this gene, the telomeric copy, often accompany deletions of the neighboring SMN1 gene in spinal muscular atrophy (SMA) patients, and so it is thought that this gene may be a modifier of the SMA phenotype. The function of this protein is not known; however, it bears low-level homology with the RNA-binding domain of matrin-cyclophilin, a protein which colocalizes with small nuclear ribonucleoproteins (snRNPs) and the SMN1 gene product. Alternatively spliced transcripts have been documented but it is unclear whether alternative splicing occurs for both the centromeric and telomeric copies of the gene. [provided by RefSeq, Jul 2008].