006   A Phenotypic Variant of Marie Unna Hereditary Hypotrichosis Does Not Map to Chromosomes 8p21

Jack Green 1, 3 , David de Berker 2 , Elizabeth Fitzpatrick 3 , Susan Forrest 3 , Rod Sinclair 1 . 1 Department of Dermatology, St.Vincent’s Hospital, Melbourne, Australia; 2 Bristol Royal Infirmary, Bristol, England; 3 Murdoch Childrens Research Institute, Melbourne, Australia

The purpose of this study was to compare members of a family with Marie Unna Hereditary Hypotrichosis living in Scotland and Australia clinically and genotypically to previous described Marie Unna families. Twenty-two members of this family were examined and genomic DNA extracted. The known Marie Unna locus at 8p21 was analysed using microsatellite markers This family displayed a milder divergent phenotype of Marie Unna Hereditary Hypotrichosis segregating in an autosomal dominant fashion over four generations. Thirteen members of the family we examined (six male, seven female) were affected. Compared with previous reports, this family displays a milder phenotype. Onset of alopecia occurs in the late 2 nd decade or early 3rd decade. Eyebrows are either preserved or only mildly affected. In some affected individuals, body hair is normal with two affected males displaying a beard of normal density. Most of those affected had varying degrees of associated onycholysis with some also displaying koilonychia. Two of the affected had cleft lip and palate. Two affected ancestors also had cleft lip and palate. This feature was not found in unaffected individuals. Linkage analysis using the markers D8S258 D8S282 D8S560 and D8S298 resulted in significant negative LOD scores for three out of four markers at q = 0.05 ranging from –6.99 to –1.64. This demonstrates that the gene causing this variant phenotype of Maire Unna Hereditary Hypotrichosis is not present at the 8p21 locus and that this condition is genetically heterogenous.