Chimerism 47,XY,+21/46,XX in a female infant with anencephaly and other congenital defects

Chimerism is rare in humans and is usually discovered accidentally when a 46,XX and 46,XY karyotype is found in a same individual. We describe a malformed female infant with neural tube defect (NTD) and a 47,XY,+21[5]/46,XX[30] karyotype.3637Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP