Trisomy 16 in a mid-trimester IVF foetus with multiple abnormalities.

Department Medical and Molecular Genetics, The Guy's, King's and St Thomas' Hospitals School of Medicine, King's College London, UK. mary.seller@genetics.kcl.ac.uk

An 18 week foetus with multiple system abnormalities was found to have full trisomy 16. This appears to be only the third reported case surviving into mid-gestation; typically, this common aneuploidy dies post-implantation. Similarities exist in the abnormalities found in the three cases suggesting that there is a 'surviving' trisomy 16 phenotype. It is characterised by: absent hemidiaphragm, pulmonary hypoplasia/aplasia, major cardiac defect, small chest, vertebral and rib defects, cystic kidneys, absent gall bladder, multiple spleens and imperforate anus, together with cleft palate, nuchal webbing/cystic hygroma, microcephaly, marked dysmorphic facial features and dorsiflexed great toe.

PMID: 15194958 [PubMed - indexed for MEDLINE]