Département de Biologie, Laboratoire de Génétique, Immunologie et Pathologie Humaine, Faculté des Sciences de Tunis, Tunis, Tunisia.
Br J Dermatol. 2013 Mar;168(3):583-7. doi: 10.1111/bjd.12050.
Psoriasis is a relapsing chronic inflammatory skin disease affecting all population groups, with a peak prevalence of 3% in northern European and Scandinavian caucasians. Epidemiological studies have implicated a genetic component to psoriasis. In the past 12 years multiple genome-wide linkage analyses have identified putative susceptibility loci on several chromosomes, with a major locus in the major histocompatibility complex region.
To investigate the genetic basis of familial psoriasis in the Tunisian population using a genome-wide linkage scan in seven ultiplex psoriatic families from Tunisia.
Following single nucleotide polymorphism (SNP) genotyping on the Affymetrix 10K SNP array, we performed nonparametric linkage (NPL) multipoint analyses to identify genotypes and obtain evidence for linkage with psoriasis across the genome.
No chromosomal region gave consistent evidence for linkage, providing evidence for genetic heterogeneity in Tunisian psoriasis families. Significant evidence for linkage of psoriasis to chromosome 2p12 was seen in one family. We also identified several regions of tentative psoriasis linkage on chromosomes 2q, 4q, 6p, 11q, 12q, 9q and 13q. One family exhibiting suggestive evidence for linkage to 17q25 (PSORS2) was identified and all affected members harboured a p.Gly117Ser mutation in CARD14 (caspase recruitment domain family, member 14), recently reported to lead to psoriasis in a large family from the U.S.A.
Our results support the genetic heterogeneity of psoriasis in the Tunisian population, provide confirmatory evidence for a novel psoriasis locus at chromosome 2p12 and reveal a psoriasis family with a mutation at PSORS2.
银屑病是一种反复发作的慢性炎症性皮肤病，影响所有人群，北欧和斯堪的纳维亚白种人中的发病率峰值为 3%。流行病学研究表明银屑病与遗传因素有关。在过去的 12 年中，多项全基因组连锁分析已经确定了几个染色体上的假定易感基因座，其中一个主要基因座位于主要组织相容性复合物区域。
使用来自突尼斯的 7 个多态性银屑病家系的全基因组连锁扫描，研究突尼斯人群中家族性银屑病的遗传基础。
在 Affymetrix 10K SNP 芯片上进行单核苷酸多态性（SNP）基因分型后，我们进行了非参数连锁（NPL）多点分析，以确定基因型并在整个基因组中获得与银屑病连锁的证据。
没有染色体区域给出一致的连锁证据，这为突尼斯银屑病家系的遗传异质性提供了证据。在一个家系中发现银屑病与 2p12 染色体的连锁具有显著意义。我们还在染色体 2q、4q、6p、11q、12q、9q 和 13q 上确定了几个暂定银屑病连锁区域。一个表现出与 17q25（PSORS2）连锁的家族被鉴定为具有提示性证据，所有受影响的成员均携带 CARD14（半胱氨酸天冬氨酸蛋白酶募集域家族，成员 14）中的 p.Gly117Ser 突变，最近在美国的一个大家庭中发现该突变可导致银屑病。
我们的结果支持突尼斯人群中银屑病的遗传异质性，为 2p12 上的一个新银屑病基因座提供了确认性证据，并揭示了一个具有 PSORS2 突变的银屑病家族。
