X-linked visceral heterotaxy type 1 is a very rare form of heterotaxy that has only been reported in a few families. Heterotaxy is the right/left transposition of thoracic and/or abdominal organs. This condition is caused by mutations in the ZIC3 gene, is inherited in an X-linked recessive fashion, and is usually seen in males. Physical features include heart abnormalities such as dextrocardia, transposition of great vessels, ventricular septal defect, patent ductus arteriosus, pulmonic stenosis; situs inversus, and missing (asplenia) and/or extra spleens (polysplenia). Affected individuals can also experience abnormalities in the development of the midline of the body, which can cause holoprosencephaly , myelomeningocele, urological anomalies, widely spaced eyes (hypertelorism), cleft palate, and abnormalities of the sacral spine and anus. Heterotaxia with recurrent respiratory infections are called primary ciliary dyskinesia.