Achondrogenesis type II is an autosomal-dominant disease leading to severe 
micromelic dwarfism. Here, we report on the postmortem identification of a de 
novo heterozygous mutation in the COL2A1 gene (c.1529G>A, p.Gly510Asp) in a 
fetus who presented with generalized hydrops fetalis and severe micromelia 
during prenatal sonographic examinations. Initially, a reciprocal translocation 
t(4;17)(q31;p13) was detected in this fetus by chorionic villus sampling. 
Subsequent chromosomal analysis of maternal and paternal blood showed that the 
patient's mother was carrier of the same reciprocal translocation. SNP array 
analysis of the fetus did not provide evidence for chromosomal imbalances or 
CNVs that could be associated with the fetal phenotype. The coexistence of a 
cytogenetic (reciprocal translocation) and a molecular genetic (COL2A1 mutation) 
abnormality in the fetus carries important implications for genetic counseling.