ABSTRACT
<p><b>OBJECTIVE</b>To report on prenatal diagnosis and follow up of two patients with paternal uniparental disomy of chromosome 6 (pUPD6).</p><p><b>METHODS</b>Fetal cells were subjected to in situ culturing and G-banded chromosomal analysis. DNA samples of the fetuses and their parents were also analyzed with single nucleotide polymorphism microarray (SNP array).</p><p><b>RESULTS</b>Both fetuses had a normal male karyotype. SNP array analysis showed both have carried pUPD6.</p><p><b>CONCLUSION</b>pUPD6 can lead to transient neonatal diabetes mellitus type 1. Homozygous status of recessive mutations, disorder of gene imprinting, and its influence on placental function are the main factors to be considered during prenatal diagnosis and genetic counseling for pUPD6.</p>