Refined localization of a punctate palmoplantar keratoderma gene to a 5.06-cM region at 15q22.2-15q22.31.
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 (theta = 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 15q22.2-15q22.31.
Gao
M
M
Institute of Dermatology and Department of Dermatology at no. 1 Hospital, Anhui Medical University, 69 Meishan Road, Hefei, Anhui 230032, China.
Yang
S
S
Li
M
M
Yan
K L
KL
Jiang
Y X
YX
Cui
Y
Y
Xiao
F L
FL
Shen
Y J
YJ
Chen
J J
JJ
Liu
J B
JB
Xu
S J
SJ
Huang
W
W
Zhang
X J
XJ
D000293:Adolescent; D000328:Adult; D002648:Child; D002874:Chromosome Mapping / Q000379:methods; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007645:Keratoderma, Palmoplantar / Q000235:genetics*; D008126:Lod Score; D008297:Male; D010375:Pedigree