Familial dup(8)(p12p21.1): Mild phenotypic effect and review of partial 8pduplications

We describe a family with direct transmission of a duplication of 8p12-->8p 21.1. The phenotype of affected realtives included mild mental retardation but no minor anomalies. The duplication was identified by means of GTG-band ing and fluorescence in situ hybridization with a probe specific for 8p12 g enerated by microdissection and degenerate oligonucleotide primed-polymeras e chain reaction. Assay of glutathione reductase, which has been localised to 8p21.1, was significantly increased when compared with controls with nor mal chromosomal constitution. To the best of our knowledge, a proximal dire ct duplication of 8p restricted to subbands p12-->p21.1 has not been report ed so far. The reported aberration is compared with other partial duplicati ons of 8p, in particular to inversion duplications 8p and to small direct d istal duplications involving 8p23.1. Am. J. Med. Genet. 94:306-310, 2000. ( C) 2000, Wiley-Liss, Inc.