美國(guó)南加州大學(xué)日前發(fā)表公報(bào)稱，該大學(xué)研究人員和中國(guó)北京協(xié)和醫(yī)學(xué)院的同行合作,，發(fā)現(xiàn)一種染色體異常能導(dǎo)致全身毛發(fā)過(guò)度生長(zhǎng)，即俗稱的“毛人”,。
“毛人”是一種罕見(jiàn)的遺傳疾病,，學(xué)名為先天性多毛癥。男性患者整個(gè)臉部,、包括眼瞼以及上半身長(zhǎng)滿毛發(fā),，而女性全身都長(zhǎng)滿毛發(fā)。研究人員稱,，他們的發(fā)現(xiàn)將有助于開(kāi)發(fā)抑制毛發(fā)過(guò)度生長(zhǎng)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(xué)院張學(xué)教授為首的這個(gè)研究小組在新一期《美國(guó)人類遺傳學(xué)期刊》發(fā)表論文說(shuō)，張學(xué)等中方研究人員在為中國(guó)一個(gè)家庭進(jìn)行檢查時(shí),，首先發(fā)現(xiàn)了這種導(dǎo)致毛發(fā)過(guò)度生長(zhǎng)的遺傳現(xiàn)象,。美方研究人員也在一個(gè)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(xué)等人首先發(fā)現(xiàn)患者的5號(hào)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(hào)染色體的一段插入,。
研究人員解釋說(shuō)，當(dāng)X染色體被其他染色體的“外來(lái)”DNA序列插入時(shí),，位于X染色體上的某個(gè)基因可能被“激活”,，從而刺激毛發(fā)生長(zhǎng)，導(dǎo)致先天性多毛癥,。他們認(rèn)為,，與毛發(fā)生長(zhǎng)有關(guān)的SOX3基因可能起到了關(guān)鍵作用。
早些時(shí)候,，科學(xué)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(fù)出現(xiàn)。美方研究人員帕特爾說(shuō),，刺激毛發(fā)生長(zhǎng)的遺傳信息很可能一直存在于基因組中,，不過(guò)沒(méi)有表達(dá)。如果進(jìn)一步的研究能證實(shí)插入某段序列可以激活基因,、刺激毛發(fā)生長(zhǎng),，未來(lái)人們可望據(jù)此尋找治療禿頂和遏制毛發(fā)過(guò)度生長(zhǎng)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.
