Variation in Gene Expression in Neurofibromatosis Type 1

1型神经纤维瘤病（NF 1）是一种常见的（约10万美国人）细胞生长失调的遗传性疾病。 受影响的人可以发展多个（数十个，数百个或数千个）称为神经纤维瘤的柔软肉质肿瘤。 患有NF 1的人也会患上恶性癌症。 NF 1的治疗方法有限，无法治愈。 在这个时候，基本上是不可能预测的严重程度的障碍。 除了少数例外，无论是相关基因（NF 1）的突变检测，还是其他受影响家庭成员的严重程度，都不能帮助估计病情的临床过程。 在这项研究中，我们研究了广泛的变异性严重程度与NF 1的家庭。 在我们的翻译方法中，在1型神经纤维瘤病的基因表达变异方案中，我们使用各种方法（体格检查，磁共振成像（MRI），皮肤和眼睛摄影，超声心动图，牙科评估）定量评估NF 1家族。我们计划将这些测量的差异与基因表达的差异相关联，如通过微阵列所确定的。 最终目标是确定与严重程度相关的基因。这些基因的差异（如单核苷酸多态性（SNP））可能有助于预测疾病的严重程度。 与严重程度相关的基因产物也可能是有用的治疗靶点。 博士斯图尔特于2004年11月底加入NHGRI。 IRB于2005年4月批准了我们的项目，此后不久就开始招募。到2008财年末，我们已经对大约100名受NF 1影响的个体进行了表型分析，并收集了几乎所有父母的DNA。 作为一个试点项目，我们培养了25个淋巴母细胞系（LCL）从这个表型组的个人受NF 1，收获RNA和杂交到微阵列（表达谱）。 然后，我们检查了各种表型（高度，咖啡牛奶斑点数量，肿瘤负荷等）与阵列上表达的约24，000个基因中的每一个之间的相关性。我们确定了一个基因，其水平似乎影响NF 1个体的身高。然后，我们扩大了调查和培养LCL从约75个人与NF 1和约25个控制。 我们目前正在研究这100名受试者的表达谱与表型数据的相关性。我们的目标是1）验证在初步研究中鉴定的基因作为修饰基因（NF 1中的身高），2）鉴定其他假定的修饰基因。 我们还与国家癌症研究所的Brigitte Widemann博士和托马斯Hornyak博士合作开发了一个合作项目（使用Bench-to-Bedside计划的资金），以调查神经纤维瘤的生长和生物学。 该项目名为1型神经纤维瘤病中真皮神经纤维瘤的自然史和生物学，于2006年5月获得NHGRI IRB的批准。它的目的是调查皮肤神经纤维瘤的生长速度和外观速度使用几种成像方式。我们还将活检皮肤神经纤维瘤和正常皮肤。为了简化招募，资格标准与我们的主要项目重叠，1型神经纤维瘤病基因表达变异。 到2008财年末，我们对12例NF 1患者的真皮神经纤维瘤进行了纵向评估。 由于斯图尔特博士是一名内科医生，他对NF 1影响成人的表现特别感兴趣。 为此，我们一直在评估成人中具有独特和未被认识到的疾病特征的NF 1个体。 到2008财政年度末，我们已经切除了四个NF 1患者的血管球瘤，这是一种罕见但疼痛的指尖良性肿瘤。 我们在了解肿瘤发展的分子机制方面取得了重大进展，并正在准备一份手稿，详细介绍我们的发现。另一份研究NF 1成人Lisch结节的手稿也在准备中。 在2008财政年度，我们在《美国医学遗传学杂志》上发表了一篇关于9 q亚端粒缺失综合征的特邀评论，斯图尔特博士在另一家机构担任遗传学研究员时描述了一种罕见的染色体疾病。我们在2007年美国人类遗传学会年会、2008年美国医学遗传学会年会和2008年儿童肿瘤基金会年会上介绍了我们的研究结果。

Neurofibromatosis type 1 (NF1) is a common (approximately 100,000 Americans) genetic disorder of dysregulated cell growth. Affected people can develop multiple (tens, hundreds, or thousands) of soft fleshy tumors called neurofibromas. People with NF1 also develop malignant cancers. There are limited therapies and no cures for NF1. At this time it is essentially impossible to predict the severity of the disorder. With few exceptions, neither mutation testing of the involved gene (NF1) nor the severity of other affected family members help in estimating the clinical course of the condition. In this study we study the wide variability in severity seen in families with NF1. In our translational approach in the protocol Variation in Gene Expression in Neurofibromatosis Type 1 we quantitatively evaluate families with NF1 using a variety of methods (physical exam, magnetic resonance imaging (MRI), skin and eye photography, echocardiography, dental evaluation). We plan to correlate differences in these measurements with differences in the expression of genes, as determined by a microarray. The ultimate goal is to identify genes associated with severity. Differences in these genes (such as single nucleotide polymorphisms (SNPs)) may be useful in predicting the severity of the disorder. Gene products associated with severity may also be useful therapeutic targets. Dr. Stewart joined NHGRI at the end of November 2004. The IRB approved our project in April 2005 and recruitment started shortly thereafter. By the end of fiscal 2008, we had phenotyped approximately 100 individuals affected with NF1 and collected DNA from nearly all their parents. As a pilot project, we cultured 25 lymphoblastoid cell lines (LCLs) from this phenotyped group of individuals affected with NF1, harvested RNA and hybridized it to microarrays (expression profiling). We then examined the correlation between a variety of phenotypes (height, number of caf-au-lait spots, tumor burden, etc) and each of the approximately 24,000 genes expressed on the array. We identified a gene whose level appears to influence height in individuals with NF1. We then expanded the investigation and cultured LCLs from approximately 75 individuals with NF1 and approximately 25 controls. We are currently investigating the correlation of expression profiles of these 100 subjects with phenotype data. Our goal is to 1) validate the gene identified in the pilot study as a modifier gene (for height in NF1) and 2) identify other putative modifier genes. We have also developed a collaborative project (using funds from the Bench-to-Bedside program) with Dr. Brigitte Widemann and Dr. Thomas Hornyak of the National Cancer Institute to investigate the growth and biology of neurofibromas. The project, titled Natural history and biology of dermal neurofibromas in neurofibromatosis type 1 was approved by the NHGRI IRB in May 2006. It is designed to investigate the growth rate and rate of appearance of dermal neurofibromas using several imaging modalities. We will also biopsy a dermal neurofibroma and normal skin. To streamline recruiting, the eligibility criteria overlap with that of our primary project, Variation in Gene Expression in Neurofibromatosis Type 1. By the end of fiscal 2008, we were evaluating, longitudinally, the dermal neurofibromas from 12 individuals affected with NF1. Since Dr. Stewart is trained as an internist, he has a special interest in manifestations of NF1 affecting adults. To this end, we have been evaluating individuals with NF1 with unique and under-recognized disease features in the adult. By the end of fiscal 2008 we had resected glomus tumors from four individuals with NF1, which are uncommon but painful benign tumors in the fingertips. We have made significant progress in understanding the molecular mechanism of the development of the tumors and are preparing a manuscript detailing our findings. Another manuscript investigating Lisch nodules in adults with NF1 is also in preparation. In fiscal 2008, we published in the American Journal of Medical Genetics an invited review on the 9q subtelomere deletion syndrome, an uncommon chromosomal disorder Dr. Stewart described as a genetics fellow at another institution. We presented our findings at the 2007 annual meeting of the American Society of Human Genetics, 2008 annual meeting of the American College of Medical Genetics and the 2008 annual meeting of the Childrens Tumor Foundation.