An interstitial de-novo microdeletion of 3q26.33q27.3 causing severe intrauterine growth retardation.

Chromosomal abnormalities involving an interstitial or a terminal deletion of 3q26.33 and/or 3q27 have rarely been described. Here we report on a fetus of 22+1 weeks' gestational age with severe intrauterine growth restriction and multiple abnormalities detected by ultrasound examination. Post-mortem molecular cytogenetic investigation (array-comparative genomic hybridization) identified a de-novo interstitial ∼6.17 Mbp microdeletion of 3q26.33q27.3. The clinical and molecular findings in this patient are compared with the previous literature on cases with overlapping interstitial 3q-deletions (seven cases in total). The common phenotype observed in patients with a microdeletion involving 3q26.33q27.3 includes severe prenatal and postnatal growth retardation (including microcephaly), developmental delay, central nervous system anomalies, and several facial characteristics (abnormally shaped ears, broad nasal tip, epicanthal folds, micrognathia/retrognathia, short philtrum). No genotype-phenotype correlation could be established for severe (intrauterine) growth retardation. We conclude that deletions of 3q26.33q27.3 are associated with a profoundly abnormal phenotype, with severe intrauterine growth retardation as its most striking feature.