LETM2 is a 491 amino acid protein that is localized to the mitochondrial membrane and contains one LETM1 domain. Despite its name, LETM2, which is preferentially expressed in sperm and testis, does not contain any EF-hand domains. There are four isoforms of LETM2 that are produced as a result of alternative splicing events. A homolog of LETM2, LETM1 is thought to be involved in maintaining normal mitochondrial function and overall cell viability. Deletions in the gene encoding LETM1 are associated with Wolf-Hirschhorn syndrome (WHS), a congenital syndrome characterized by a number of abnormalities, including mental retardation, seizures, heart defects, fused teeth, hearing loss, a webbed neck and renal abnormalities. The LETM2 gene is located on chromosome 8, which is made up of nearly 146 million bases and encodes about 800 genes.