Paper

A serpin gene cluster on human chromosome 6p25 contains PI6, PI9 and ELANH2 which have a common structure almost identical to the 18q21 ovalbumin serpin genes
J. Sun^a, R. Stephens^b, G. Mirza^b, H. Kanai^a, J. Ragoussis^b, P.I. Bird<sup>a

a</sup>Department of Medicine, Monash Medical School, Clive Ward Centre, Box Hill Hospital, Box Hill (Australia); and
^bGenomics Laboratory, Division of Medical Molecular Genetics, UMDS, Guy's Hospital, London (UK)

Address of Corresponding Author

Cytogenet Cell Genet 1998;82:273-277 (DOI: 10.1159/000015118)

  Abstract.

The human genes encoding the “ovalbumin'' subgroup of closely related serine proteinase inhibitors (serpins) are located at 18q21.3 and 6p25. Those at 6p25 include proteinase inhibitor 6 (PI-6; gene symbol PI6), proteinase inhibitor 9 (PI-9; gene symbol PI9) and monocyte neutrophil elastase inhibitor (M/NEI; gene symbol ELANH2). Here we describe the fine mapping of these genes to a 200-kb region of chromosome 6 that includes the markers WI-8835 and D6S1338, and the establishment of the gene order: tel-PI6-PI9-ELANH2-cen. PI6 and ELANH2 are transcribed towards the telomere, and structural analysis shows that PI6 and PI9 are organized identically, having seven exons and six introns. PI6 and PI9 are almost identical in structure to the ovalbumin serpin genes at 18q21.3. The 18q21.3 genes have an extra exon and intron, otherwise all the other exon/intron boundaries are conserved between the two groups. These results represent the first detailed map of the chromosome 6 serpin gene cluster, and demonstrate that although they are very closely related, the 6p25 and 18q21q23 ovalbumin serpin genes form two structurally distinct groups. These findings do not support a previously proposed model for evolution of the clusters which invoked an inter-chromosomal duplication of the entire 6p25 group to 18q21.3.

  Author Contacts

Request reprints from Dr. P. Bird, Department of Medicine, Clive Ward Centre,Box Hill Hospital, Box Hill 3128 (Australia); telephone: +61 3 9895 0316;fax: +61 3 9895 0332; e-mail: philb@boxhill.med.monash.edu.au

  Article Information

Supported by the National Health and Medical Research Council of Australia, and by the MRC-HGMP grant G9533412. R.S. was the recipient of an MRC studentship.

Received: Received 2 June 1998;
manuscript accepted 10 July 1998.
Number of Print Pages : 5
Number of Figures : 3, Number of Tables : 1, Number of References : 24