Short reports A pericentric inversion duplication of the subcentromeric region of chromosome 12q The proband, a 1 year old girl, was referred because of dysmorphic features and developmental delay. There was no family history of congenital abnormalities and the mother had received no drugs during her pregnancy. The mother was 25 and the father 26 years old at the time of the birth. The pregnancy was normal and the birth uncomplicated. She learnt to sit at 3 months and to crawl at 5 months. She now walks unaided, yet she does not talk or make any sounds. She appears to understand what is said to her. The only abnormalities are a large protruding tongue and epicanthic folds. Cultured peripheral lymphocytes were used for chromosomal analysis with GTG and R banding. All 15 cells examined showed an elongation of the short arm of one of the chromosomes 12. This was evaluated in the G banded slides as an inverted duplication in the short arm of the immediate subcentromeric region of the long arm: dup(12p)(qll-ql2) (figure). The chromosomes of both parents were normal.