Raskind W H, Bolin T, Wolff J, Fink J, Matsushita M, Litt M, Lipe H, Bird T D
Department of Medicine, University of Washington, Seattle 98195, USA.
Hum Genet. 1998 Jan;102(1):93-7. doi: 10.1007/s004390050659.
Paroxysmal dystonic choreoathetosis (PDC) is a rare neurological disorder characterized by episodes of involuntary movement, involving the extremities and face, which may occur spontaneously or be precipitated by caffeine, alcohol, anxiety, and fatigue. PDC is transmitted as an autosomal dominant trait with incomplete penetrance. A gene implicated in this paroxysmal disorder has been mapped to a 10-15 cM region on chromosome 2q31-36 in two families. We describe a third family with PDC. Two-point linkage analyses with markers linked to the candidate PDC locus were performed. A maximum two-point LOD score of 4.20 at a recombination fraction of zero was obtained for marker D2S120, confirming linkage to the distal portion of chromosome 2q. The anion exchanger gene, SLC2C, maps to this region, but the family was poorly informative for polymorphic markers within and flanking this candidate gene. Haplotype analysis revealed a critical recombination event that confines the PDC gene to a 5-cM region bounded by the markers D2S164 and D2S377. We compared the haplotype in our family with that in another chromosome 2-linked PDC family, but did not detect a region of shared genotypes. However, identifying a third family whose disease maps to the same region and narrowing the critical region will facilitate identification of the 2q-linked PDC gene.
阵发性肌张力障碍性舞蹈手足徐动症（PDC）是一种罕见的神经系统疾病，其特征为出现累及四肢和面部的不自主运动发作，这些发作可能自发出现，或由咖啡因、酒精、焦虑及疲劳诱发。PDC以常染色体显性性状伴不完全外显率遗传。在两个家族中，已将一种与该阵发性疾病相关的基因定位于2号染色体q31 - 36区的一个10 - 15厘摩区域。我们描述了第三个患有PDC的家族。对与候选PDC基因座连锁的标记进行了两点连锁分析。标记D2S120在重组率为零时获得了最大两点LOD值4.20，证实与2号染色体q远端部分连锁。阴离子交换基因SLC2C定位于该区域，但该家族对于该候选基因内部及侧翼的多态性标记信息较少。单倍型分析揭示了一个关键的重组事件，将PDC基因限定于由标记D2S164和D2S377界定的一个5厘摩区域内。我们将我们家族的单倍型与另一个与2号染色体连锁的PDC家族的单倍型进行了比较，但未检测到共享基因型区域。然而，鉴定出第三个疾病定位于同一区域的家族并缩小关键区域，将有助于鉴定与2号染色体q连锁的PDC基因。
