What causes Holoprosencephaly?
The cause of Holoprosencephaly (HPE) is currently unknown. Often, no specific cause can be identified. Suggested risk factors include maternal diabetes, infections during pregnancy (syphilis, toxoplasmosis, rubella, herpes, cytomegalovirus), and various drugs taken during pregnancy (alcohol, aspirin, lithium, thorazine, anticonvulsants, hormones, retinoic acid). Women with previous pregnancy loss and first trimester bleeding are also more likely to have a child diagnosed with Holoprosencephaly. Although many children with Holoprosencephaly have normal chromosomes, specific chromosomal abnormalities have been identified in some patients. There is evidence that in some families, HPE is inherited (autosomal dominant as well as autosomal or X-linked recessive inheritance). Features consistent with familial transmission of the disease (e.g., a single central maxillary incisor) should be carefully assessed in parents and family members. Several genes have been identified that play a role in
