Kotecha U H, Movva S, Puri R D, Verma I C
Center of Medical Genetics, Sir Ganga Ram Hospital, New Delhi, India.
Mol Syndromol. 2012 Aug;3(2):89-93. doi: 10.1159/000339896. Epub 2012 Jul 5.
Trichohepatoenteric syndrome (THES) is characterized by chronic diarrhea, dysmorphic facies and hair abnormalities. Hepatic involvement varies from no abnormality to cirrhosis and hemochromatosis. Recently, mutations in the tetratricopeptide repeat domain 37 (TTC37) gene were identified to cause THES. The c.2808G>A variation was suggested as a possible founder mutation among the South Asians. We further report 2 unrelated cases of Asian-Indian ethnicity (Gujrati) with THES, wherein targeted mutation analysis revealed the same mutation in homozygous form in both cases. These findings, as well as haplotype analysis, corroborate the founder mutation hypothesis amongst Asian Indo-Pakistani ethnic groups. A restriction enzyme-based method is also described to identify this founder mutation. One of our probands had multiple hepatic hemangiomas, a feature not previously observed in this syndrome.
毛发肝肠综合征（THES）的特征为慢性腹泻、面容畸形和毛发异常。肝脏受累情况从无异常到肝硬化和血色素沉着症不等。最近，已确定四肽重复结构域37（TTC37）基因的突变会导致THES。c.2808G>A变异被认为可能是南亚人群中的一个奠基者突变。我们进一步报告了2例不相关的印度裔亚洲人（古吉拉特人）THES病例，其中靶向突变分析显示两例均为纯合形式的相同突变。这些发现以及单倍型分析证实了亚洲印度 - 巴基斯坦族群中的奠基者突变假说。还描述了一种基于限制性内切酶的方法来鉴定这种奠基者突变。我们的一位先证者患有多发性肝血管瘤，这是该综合征以前未观察到的特征。
