Cytogenetic variants in holoprosencephaly. Report of a case and review of the literature.

A new infant with classical features of holoprosencephaly and multiple extracranial malformations was found to have abnormal karyotype: 47, XX, + 13. Although trisomy D has been reported in a few cases, our case is the first, to our knowledge, in which positive identification of trisomy 13 was made by banding technique in cebocephaly.