摘要
Background: Punctate palmoplantar keratoderma (PPK) is a rare autosomal dominant cutaneous disorder characterized by numerous hyperkeratotic papules distributed on the palms and soles. Two loci for punctate PPK were recently found to be located on 8q24.13- 8q24.21 and 15q22- 15q24. However, no genes for this disease have been identified to date. Objectives: To refine the previously mapped regions and to identify the disease gene locus in a four- generation Chinese family with punctate PPK. Methods: Genetic linkage analysis was carried out in this family using microsatellite markers on chromosomes 8q and 15q. Two- point linkage analysis was performed using Linkage programs version 5.10 and the haplotype was constructed using Cyrillic version 2.02 software. Results: We failed to confirm our previous locus at 8q24.13- 8q24.21, but significant evidence for linkage was observed in the region of 15q with a maximum two- point LOD score of 5.38 at D15S153 (θ .=0.00). Haplotype analysis localized the punctate PPK locus within the region defined by D15S651 and D15S988. This region overlaps by 5.06 cM with the previously reported punctate PPK region. Conclusions: This study refines a disease gene causing punctate PPK to a 5- 06- cM interval at 15q22.215q22.31.
Background: Punctate palmoplantar keratoderma (PPK) is a rare autosomal dominant cutaneous disorder characterized by numerous hyperkeratotic papules distributed on the palms and soles. Two loci for punctate PPK were recently found to be located on 8q24.13- 8q24.21 and 15q22- 15q24. However, no genes for this disease have been identified to date. Objectives: To refine the previously mapped regions and to identify the disease gene locus in a four- generation Chinese family with punctate PPK. Methods: Genetic linkage analysis was carried out in this family using microsatellite markers on chromosomes 8q and 15q. Two- point linkage analysis was performed using Linkage programs version 5.10 and the haplotype was constructed using Cyrillic version 2.02 software. Results: We failed to confirm our previous locus at 8q24.13- 8q24.21, but significant evidence for linkage was observed in the region of 15q with a maximum two- point LOD score of 5.38 at D15S153 (θ .=0.00). Haplotype analysis localized the punctate PPK locus within the region defined by D15S651 and D15S988. This region overlaps by 5.06 cM with the previously reported punctate PPK region. Conclusions: This study refines a disease gene causing punctate PPK to a 5- 06- cM interval at 15q22.215q22.31.
