We have helped the genetics service laboratory at the hospital to set up screening for keratin mutations, and as a result they are now efficiently handling all the "first pass" at new EBS samples that come to Dundee. This means that they perform what is now a very routine screen, a PCR-based screen of the two major "hotspots" for EBS mutations in K5 and K14. If they find no mutations in these regions then the sample is passed over to our lab, and full sequencing of the coding regions for the whole of keratins K5 and K14 is then undertaken. Following this routine, most of the patient samples can be turned around in a couple of months and results reported back to the clinician in charge. Closer collaboration has also led to greatly improved reporting systems all round.

The second level screening obviously takes much longer to do and we are still working on improvements to speed up this process; it does however provide important insights into the overall patterns of keratin mutations and their relationship to disease phenoptye. We anticipate that the data arising from this project will improve early and accurate diagnosis of EBS in the UK population.

Within Scotland we have now screened all the known families with EBS, and in collaboration with Dr Helen Horne in Edinburgh we are in the process of writing this work up as a population study of the correlation between genotype and phenotype in EBS. This study has also provided statistics on the true frequency of the EBS disorder in Scotland, which will probably be mirrored in the UK as a whole, and the frequency within this of the different types of mutations associated with this disease.

Prenatal diagnosis has now been undertaken for 5 patient families, and the first publication of these results is in press and should be published any day now. We are still not getting a large response from the UK patient pool - the prenatal diagnosis undertaken to date have been in response to requests from non-UK sufferers - but the limited uptake is probably understandable, given the variable severity of the disorders and the sensitive nature of the issue. However, Dundee should now be able to continue to provide not only a mutation analysis service for EBS cases but also a national prenatal screening service, at least on an ad hoc basis until the numbers of requests for this service become unmanageable.

1. Corden LD, Mellerio JE, Gratian MJ, Eady RAJ, Harper JI, Lacour M, Magee G, Lane EB, McGrath JA and McLean WHI (1998). Homozygous nonsense mutation in helix 2 of K14 causes severe recessive epidermolysis bullosa simplex. Human Mutation 11: 279-285.
2. Porter RM, Reichelt J, Lunny DP, Magin TM and Lane EB (1998). The relationship between hyperproliferation and epidermal thickening in a mouse model of BCIE. J Invest Dermatol 110: 951-957.
3. Smith, FJD, Maingi C, Covello SP, Higgins C, Schmidt M, Lane EB, Uitto J, Leigh IM and McLean I (1998). Genomic organisation and fine mapping of the keratin 2e gene (KRT2E): K2e V1 domain polymorphism and novel mutations in Ichyosis Bullosa of Siemens. J Invest Dermatol 111: 817-821.
4. Swensson O, Langbein L, McMillan JR, Churchill LJ, Leigh IM, McLean WHI, Lane EB and Eady RAJ (1998). Specialised keratin expression pattern in human ridged skin as an adaptation to high physical stress. British J Dermatology 139: 767-775.
5. Shemanko CS, Mellerio JE, Tidman MJ, Lane EB and Eady RAJ (1998). Severe palmo-plantar hyperkeratosis in Dowling-Meara epidermolysis bullosa simplex caused by a mutation in the keratin 14 gene (KRT14). J Invest Dermatol 111: 893-895.
6. Kremer H, Lavrijsen APM, McLean WHI, Lane EB, Melchers D, Ruiter DJ, Mariman ECM and Steijlen PM (1998). An atypical form of bullous congenital ichthyosiform erythroderma is caused by a mutation in the L12 linker region of keratin 1. J Invest Dermatol 111: 1224-1226.
7. McLean WHI, Morley SM, Higgins C, Bowden PE, White M, Leigh IM and Lane EB (1999). Novel and recurrent mutations in keratin 10 causing bullous congenital ichthyosiform erythroderma. Experimental Dermatol 8: 120-123.
8. Rugg EL, Rachet-Prehu M-O, Rochat A, Barrandon Y, Goossens M, Lane EB and Hovnanian A (1999). Donor splice site mutation in keratin 5 causes in-frame removal of 22 amino acids of H1 and 1A rod domains in Dowling-Meara epidermolysis bullosa simplex. Eur J Hum Gen 7: 293-300.
9. Rugg EL, Magee GJ, Wilson NJ, Brandrup F, Hamburger J and Lane EB (1999) Identification of two novel mutations in keratin 13 as the cause of white sponge naevus. Oral Diseases 5: 321-324.
10. Shemanko CS, Horn HM, Keohane SG, Hepburn N, Kerr AIG, Atherton DJ, Tidman MJ and Lane EB. Laryngeal involvement in the Dowling-Meara variant of epidermolysis bullosa simplex with keratin mutations of severly disruptive potential. British Journal of Dermatology (in press).
11. EL Rugg, D Baty, CS Shemanko, G Magee, S Polak, R Bergman, T Kadar, M Boxer, T Falik-Zaccai, Z Borochowitz & EB Lane (2000) DNA based prenatal testing for the skin blistering disorder epidermolysis bullosa simplex. Prenatal Diagnosis (In press)

Task 1:

Identify genes in skin cells which are responsible for the defective structural proteins in skin in EBS

• partly achieved

This is an ongoing task. Even when we have identified the mutations in all the currently known families, new mutations will continue to arise.

Progress has been good, with no significant obstacles encountered.

Task 2:

Transfer the skills necessary for routine mutation analysis of EBS to the local clinical genetics service laboratory so that this can continue after the completion of this grant funding period.

• achieved

Task 3:

Establish a robust long-term reporting system between the research laboratory, the clinical service laboratory and the patient interface so that appropriate and useful information reaches the referring clinician as a quickly as possible and correctly secure mutational data arising from the clinical service activity also feedback into the research group.

• achieved