美國南加州大學日前發(fā)表公報稱,，該大學研究人員和中國北京協(xié)和醫(yī)學院的同行合作，發(fā)現(xiàn)一種染色體異常能導致全身毛發(fā)過度生長,，即俗稱的“毛人”,。
“毛人”是一種罕見的遺傳疾病,，學名為先天性多毛癥,。男性患者整個臉部,、包括眼瞼以及上半身長滿毛發(fā)，而女性全身都長滿毛發(fā),。研究人員稱,，他們的發(fā)現(xiàn)將有助于開發(fā)抑制毛發(fā)過度生長的新療法，也可能幫助找到禿頂?shù)男炉煼ā?/p>
以協(xié)和醫(yī)學院張學教授為首的這個研究小組在新一期《美國人類遺傳學期刊》發(fā)表論文說,，張學等中方研究人員在為中國一個家庭進行檢查時，首先發(fā)現(xiàn)了這種導致毛發(fā)過度生長的遺傳現(xiàn)象,。美方研究人員也在一個墨西哥家庭中發(fā)現(xiàn)了類似的遺傳現(xiàn)象,。
在中方的研究中，張學等人首先發(fā)現(xiàn)患者的5號染色體有一段插入了X染色體,。在這一成果的啟示下,，美方研究人員發(fā)現(xiàn)，墨西哥患者X染色體的相同部位被4號染色體的一段插入,。
研究人員解釋說,，當X染色體被其他染色體的“外來”DNA序列插入時，位于X染色體上的某個基因可能被“激活”,，從而刺激毛發(fā)生長,，導致先天性多毛癥。他們認為,，與毛發(fā)生長有關的SOX3基因可能起到了關鍵作用,。
早些時候，科學家發(fā)現(xiàn)先天性多毛癥屬家族隔代遺傳,，其癥狀可能多代以后才重復出現(xiàn),。美方研究人員帕特爾說，刺激毛發(fā)生長的遺傳信息很可能一直存在于基因組中，不過沒有表達,。如果進一步的研究能證實插入某段序列可以激活基因,、刺激毛發(fā)生長，未來人們可望據(jù)此尋找治療禿頂和遏制毛發(fā)過度生長的新方法,。（生物谷Bioon.com）
生物谷推薦原文出處：
The American Journal of Human Genetics DOI:10.1016/j.ajhg.2011.05.004
X-Linked Congenital Hypertrichosis Syndrome Is Associated with Interchromosomal Insertions Mediated by a Human-Specific Palindrome near SOX3
Hongwen Zhu1, 2, 9, Dandan Shang1, 9, Miao Sun1, 9, Sunju Choi3, 9, Qing Liu1, Jiajie Hao4, Luis E. Figuera5, Feng Zhang6, Kwong Wai Choy7, Yang Ao1, Yang Liu8, Xiao-Lin Zhang1, Fengzhen Yue2, Ming-Rong Wang4, Li Jin6, Pragna I. Patel3, 9, Tao Jing2, 9 and Xue Zhang
X-linked congenital generalized hypertrichosis (CGH), an extremely rare condition characterized by universal overgrowth of terminal hair, was first mapped to chromosome Xq24-q27.1 in a Mexican family. However, the underlying genetic defect remains unknown. We ascertained a large Chinese family with an X-linked congenital hypertrichosis syndrome combining CGH, scoliosis, and spina bifida and mapped the disease locus to a 5.6 Mb critical region within the interval defined by the previously reported Mexican family. Through the combination of a high-resolution copy-number variation (CNV) scan and targeted genomic sequencing, we identified an interchromosomal insertion at Xq27.1 of a 125,577 bp intragenic fragment of COL23A1 on 5q35.3, with one X breakpoint within and the other very close to a human-specific short palindromic sequence located 82 kb downstream of SOX3. In the Mexican family, we found an interchromosomal insertion at the same Xq27.1 site of a 300,036 bp genomic fragment on 4q31.2, encompassing PRMT10 and TMEM184C and involving parts of ARHGAP10 and EDNRA. Notably, both of the two X breakpoints were within the short palindrome. The two palindrome-mediated insertions fully segregate with the CGH phenotype in each of the families, and the CNV gains of the respective autosomal genomic segments are not present in the public database and were not found in 1274 control individuals. Analysis of control individuals revealed deletions ranging from 173 bp to 9104 bp at the site of the insertions with no phenotypic consequence. Taken together, our results strongly support the pathogenicity of the identified insertions and establish X-linked congenital hypertrichosis syndrome as a genomic disorder.
