A novel acropectoral syndrome maps to chromosome 7q36
- Munis Dundarb,
- Tilda M Gordona,
- Irfan Ozyazganb,
- Fahri Oguzkayab,
- Yusuf Ozkulb,
- Alexander Cookea,
- A Graham Wilkinsonc,
- Susan Hollowayd,
- Frances R Goodmane,
- John L Tolmiea
- aDuncan Guthrie Institute of Medical Genetics, Yorkhill, Glasgow G3 8SJ, UK, bDepartments of Medical Genetics, Plastic and Reconstructive Surgery, and Thoracic Surgery, Erciyes University Medical Faculty, 38039 Kayseri, Turkey, cDepartment of Radiology, Royal Hospital for Sick Children, Edinburgh EH9 1LF, UK, dClinical Genetics, Western General Hospital, Edinburgh EH4 2XU, UK, eMolecular Medicine Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
- Ms Gordon (molecular),caf2e{at}pop-server.cent.gla.ac.ukor Dr Dundar (clinical), mdundar{at}hotmail.com
- Revised 31 January 2001
- Accepted 2 February 2001
Abstract
F syndrome (acropectorovertebral syndrome) is a dominantly inherited skeletal dysplasia affecting the hands, feet, sternum, and lumbosacral spine, which has previously been described in only two families. Here we report a six generation Turkish family with a related but distinct dominantly inherited acropectoral syndrome. All 22 affected subjects have soft tissue syndactyly of all fingers and all toes and 14 also have preaxial polydactyly of the hands and/or feet. In addition, 14 have a prominent upper sternum and/or a blind ending, inverted U shaped sinus in the anterior chest wall. Linkage studies and haplotype analysis carried out in 16 affected and nine unaffected members of this family showed that the underlying locus maps to a 6.4 cM interval on chromosome 7q36, between EN2and D7S2423, a region to which a locus for preaxial polydactyly and triphalangeal thumb-polysyndactyly has previously been mapped. Our findings expand the range of phenotypes associated with this locus to include total soft tissue syndactyly and sternal deformity, and suggest that F syndrome may be another manifestation of the same genetic entity. In mice, ectopic expression of the geneSonic hedgehog(Shh) in limb buds and lateral plate mesoderm during development causes preaxial polydactyly and sternal defects respectively, suggesting that misregulation ofSHH may underlie the unusual combination of abnormalities in this family. A recently proposed candidate gene for 7q36 linked preaxial polydactyly is LMBR1, encoding a novel transmembrane receptor which may be an upstream regulator of SHH.
