First trimester diagnosis of Pallister-Killian syndrome in a fetus with suggestive abnormalities.

Background: Pallister-Killian Syndrome is a rare, sporadic chromosomal disorder characterized by a tetrasomy 12p often in mosaic. It is only in 2000 that the first case of PKS was diagnosed in the first trimester further to an increased nuchal translucency.

Aim: Report a new case.

Case Report: To our knowledge, we present the first case of early prenatal diagnosis of Pallister Killian Syndrome due to the presence of an increased nuchal translucency, a diaphragmatic hernia, a typical facial dysmorphism and a micromelia of a predominantly rhizomelic type . A chorionic cells biopsy showed a normal karyotype. The diagnosis was revealed on cytogenetic analysis of amniotic fluid sampling.

Conclusion: The main ultrasound indicators of PKS seem to be: Hydramnios, congenital diaphragmatic hernia (CDH) and a micromelia of a rhizomelic type. The Hydrops fetalis, hygroma coli or increased nuchal translucency (INT), fetal overgrowth, ventriculomegaly and presence of a sacral appendix are less common. The amniocentesis with the study of the karyotype on amniotic cells is considered to be the gold standard for the diagnosis of PKS. A good morphological study during the first trimester in search of ultrasound abnormalities highly suggestive of PKS is able to direct the cytogenetic study.