DNASE1L1 is a 302 amino acid protein that localizes to the endoplasmic reticulum and belongs to the deoxyribonuclease family. Expressed at high levels in cardiac and skeletal muscle and at lower levels in a variety of tissues throughout the body, DNASE1L1 exists as multiple alternatively spliced isoforms and is thought to function in a similar manner to DNase l, possibly mediating internucleosomal DNA degradation via catalytic cleavage events. The gene encoding DNASE1L1 maps to human chromosome X, which contains nearly 153 million base pairs and houses over 1,000 genes. In conjunction with chromosome Y, chromosome X is responsible for sex determination. There are a number of conditions related to an abnormal number and combination of sex chromosomes, some of which include Turner's syndrome, color blindness, hemophilia and Duchenne muscular dystrophy.