Four alternatively spliced transcript variants encoding four different isoforms have been found for this nuclear gene. All isoforms contain leucine-rich repeats. Three of these isoforms are mitochondrial proteins and one of them lacks the target peptide, so is not located in mitochondrion. This gene is down-regulated in Down syndrome (DS) brain, which may represent mitochondrial dysfunction in DS patients. [provided by RefSeq, Sep 2012].