Targeted prenatal diagnosis of Pallister-Killian syndrome.

OBJECTIVE: To present five new cases of prenatally diagnosed Pallister-Killian syndrome (PKS) and to propose an approach for a targeted diagnosis.

METHOD: We retrospectively analyzed ultrasound findings and cytogenetic results in PKS. We also searched through dysmorphology databases for features occurring in PKS that could potentially be seen in prenatal ultrasound examination.

RESULTS: On the basis of collected data, frequent and distinctive features in fetuses with PKS were established. The most appropriate material and method of testing were proposed. Rhizomelic limb shortening, diaphragmatic hernia, thickened nuchal fold, increased prenasal thickness, polydactyly and polyhydramnios were frequent and distinctive findings in fetuses with PKS. Amniocentesis was the most frequent prenatal procedure for material collection. Percentage of aneuploid cells was higher in amniotic fluid than in cord blood. Cytomolecular tests were useful as confirmation as well as preliminary tests. Cytogenetic identification of the isochromosome was done in all cases except one.

CONCLUSIONS: In case of ultrasound evaluation of features frequent and distinctive for PKS in second and third trimesters of pregnancy, targeted diagnosis should be considered. Amniotic fluid instead of cord blood collection is preferable. Communication with the laboratory is important because modification of routine procedures enhances a chance for correct diagnosis. © 2017 John Wiley & Sons, Ltd.