Keratolytic winter erythema (KWE), also known as “Oudts-hoorn skin disease,” or “erythrokeratolysis hiemalis,” is an autosomal dominant skin disorder of unknown etiology characterized by a cyclical erythema, hyperkeratosis, and recurrent and intermittent peeling of the palms and soles, particularly during winter. Initially KWE was believed to be unique to South Africa, but recently a large pedigree of German origin has been identified. The disorder occurs with a prevalence of 1/7, 000 in the South African Afrikaans-speaking Caucasoid population, and this high frequency has been attributed to founder effect. After a number of candidate regions were excluded from linkage to KWE in both the German family and several South African families, a genomewide analysis was embarked on. Linkage to the microsatellite marker D8S550 on chromosome 8p22-p23 was initially observed, with a maximum LOD score (Zmax) of 9.2 at a maximum recombination fraction (θmax) of .0 in the German family. Linkage was also demonstrated in five of the larger South African families, with Zmax = 7.4 at θmax = .02. When haplotypes were constructed, 11 of 14 South African KWE families had the complete “ancestral” haplotype, and 3 demonstrated conservation of parts of this haplotype, supporting the hypothesis of founder effect. The chromosome segregating with the disease in the German family demonstrated a different haplotype, suggesting that these chromosomes do not have a common origin. Recombination events place the KWE gene in a 6-cM interval between D8S550 and D8S552. If it is assumed that there was a single South African founder, a proposed ancestral recombinant suggests that the gene is most likely in a 1-cM interval between D8S550 and D8S265.
Starfield, M., Hennies, H. C., Jung, M., Jenkins, T., Wienker, T., Hull, P., ... Reis, A. (1997). Localization of the Gene Causing Keratolytic Winter Erythema to Chromosome 8p22-p23, and Evidence for a Founder Effect in South African Afrikaans-Speakers. American Journal of Human Genetics, 61(2), 370-378. https://doi.org/10.1086/514848