Prenatal diagnosis of tetrasomy 9p with Dandy–Walker malformation

Objectives To add to the knowledge of chromosomal abnormalities associated with Dandy–Walker malformation. Methods Molecular cytogenetic analyses of a chorionic villus sampling and of an amniocentesis of a fetus with Dandy–Walker malformation and abnormal somatic development. Results All cells examined showed a 47, XY, +idic(9p)(pter→q12::q12→pter) de novo karyotype. This report describes the fourth case of a tetrasomy 9p associated with Dandy–Walker malformation Conclusions This case, together with the three previously reported cases of an association with a tetrasomy 9p, indicate that this chromosomal aberration should be looked for when Dandy–Walker malformation is detected via prenatal ultrasonography. Copyright © 2004 John Wiley & Sons, Ltd.