Coveler Karen J, Yang Sam P, Sutton ReidV, Milstein Jay M, Wu Yuan-Qing, Bois Knox-Du, Beischel Linda S, Johnson John P, Shaffer Lisa G
Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room S801, Houston, TX 77030, USA.
Hum Genet. 2002 Mar;110(3):251-6. doi: 10.1007/s00439-002-0688-4. Epub 2002 Feb 26.
Uniparental disomy of chromosome 14 (UPD 14) results in one of two distinct abnormal phenotypes, depending upon the parent of origin. This discordance may result from the reciprocal over-expression and/or under-expression of one or more imprinted genes. We report a case of segmental paternal isodisomy for chromosome 14 with features similar to those reported in other paternal disomy 14 cases. Microsatellite marker analysis revealed an apparent somatic recombination event in 14q12 leading to proximal biparental inheritance, but segmental paternal uniparental isodisomy distal to this site. Analysis of monochromosomal somatic cell hybrids containing either the paternally inherited or the maternally inherited chromosome 14 revealed no deletion of the maternally inherited chromosome 14 and demonstrated the presence of paternal sequences from D14S121 to the telomere on both chromosomes 14. Thus, the patient has paternal isodisomy for 14q12-14qter. Because the patient shows most of the features associated with paternal disomy 14, this supports the presence of the imprinted domain(s) distal to 14q12 and suggests that the proximal region of chromosome 14 does not contain imprinted genes that contribute significantly to the paternal UPD 14 phenotype.
14号染色体单亲二体（UPD 14）会导致两种不同的异常表型之一，具体取决于起源的亲本。这种不一致可能是由于一个或多个印记基因的相互过表达和/或低表达所致。我们报告了一例14号染色体节段性父源等臂二体病例，其特征与其他父源14号二体病例报道的相似。微卫星标记分析显示在14q12发生了明显的体细胞重组事件，导致近端双亲遗传，但该位点远端为节段性父源单亲二体。对含有父源或母源遗传的14号染色体的单染色体体细胞杂种进行分析，结果显示母源遗传的14号染色体没有缺失，并证明两条14号染色体上从D14S121到端粒均存在父源序列。因此，该患者为14q12 - 14qter的父源等臂二体。由于该患者表现出了与父源14号二体相关的大多数特征，这支持了14q12远端印记结构域的存在，并表明14号染色体近端区域不包含对父源UPD 14表型有显著贡献的印记基因。
