Investigation of the imprinted domain located at the chromosomal deletion associated with Prader-Willi syndrome

普瑞德威利综合征（PWS）是一种以肥胖和智力低下为特征的著名疾病。大多数患者在 15q11-q13 处有相同的染色体缺失。缺失总是发生在父本染色体上，表明涉及基因组印记。尽管在该缺失中发现了多个印记基因，但尚不清楚在该缺失之外是否还存在一些额外的印记基因，即“印记域”。我们发现了一名15号染色体大缺失的严重PWS患者，发现其远端断点比普通PWS患者的常见断点多出约20kb。使用来自该重症患者的培养细胞，我们研究了额外删除中映射的基因（EST）是否其中一些被印记。结果，我们发现这些基因至少没有被印记在淋巴母细胞中。因此，我们无法获得印迹域比想象的更大的证据。上述数据最近发表在《临床遗传学》杂志上。

Prader-Willi syndrome (PWS) is one of the famous diseases that are characterized by obesity and mental retardation. Most of the patients share the same chromosome deletion at 15q11-q13. The deletion always occurs on the paternal chromosome, suggesting involvement of the genomic imprinting. Although several imprinted genes has been discovered within this deletion, it has yet not known whether some additional imprinted genes exist outside of the deletion, "an imprinted domain".We found a severe PWS patient with a large chromosome 15 deletion and found that its distal breakpoint was located approximately 20kb more telomeric from the common breakpoint of that of the usual PWS patient. Using the cultured cells from this severe patient, we investigated genes (ESTs) mapped in the extra deleted whether some of these are imprinted. As a result, we found that none of these genes was imprinted at least in the lymphoblast cells. Therefore, we could not obtain the proof that indicates the imprinted domain was larger than thought. These above data have recently been published in Clinical Genetics.