台灣漢人的姓氏與Y染色體STR單倍型的關聯性分析

Abstract

背景與目的 Y染色體是嚴格父子相傳的基因組，即是父系遺傳，而漢人的姓氏大多繼承自父親，所以姓氏與Y染色體的遺傳在理論上是平行的，共同姓氏的男性可能會有相同或相近的Y染色體型別。在此研究中，我們分析台灣漢人不同頻率的姓氏中Y染色體短多重複序列(STR)單倍型分布情形，並與一般台灣漢人族群做比較，分析姓氏與Y染色體STR單倍型的關聯程度，以了解Y染色體STR單倍型對姓氏的特異性程度及其在法醫學人身鑑別上的應用。

研究材料與方法 我們共研究了635名彼此無親緣關係的男性，包含屬於最常見姓氏的：102位陳姓(Chen)，107位李姓(Li)，及107位林姓(Lin)；屬於次常見姓氏的：42位周姓(Zhou)，29位簡姓(Jian)，8位唐姓(Tang)，8位曹姓(Cao)；以及屬於罕見姓氏的：21位華姓(Hua)，5位尹姓(Yin)，6位阮姓(Ruan)，與200位台灣隨機姓氏漢人(TWH)。另外在TWH族群加入367位FORDDAS資料庫內台灣漢人的數據。共567位作為隨機姓氏對照組。本研究分析17個Y-STR基因座(DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a, DYS385b, DYS393, DYS391, DYS439, DYS635, DYS392, Y-GATA-H4, DYS437, DYS438, DYS448)，由所得之單倍型(haplotype)，依姓氏分組計算單倍型歧異度(haplotype diversity)，分析不同姓氏之單倍型分布，找出可能的世系聚集(descent cluster)，並觀察不同姓氏Y-STR單倍型分布與台灣漢人隨機姓氏族群的差異，以了解台灣漢人姓氏與Y染色體間的關聯性。

主要結果 在研究的十個姓氏與台灣隨機姓氏族群裡，只有華姓(Hua)呈現相對較低之單倍型歧異度(0.9143)，其餘皆相對較高。次常見姓氏簡姓(Jian)觀察到一個世系聚集(descent cluster)，包含7人共享一個Y-STR單倍型與兩個相差一步突變的單倍型，且該世系聚集佔其姓氏群集31.03%；罕見姓氏華姓(Hua)亦有觀察到一個世系聚集，包含6人共享的一個Y-STR單倍型與相差一步突變的3人共享之另一單倍群，該世系聚集佔其姓氏群集42.86%，其餘姓氏觀察到的世系聚集所佔比率皆未超過10%，且較少共享型別的情形出現。本研究僅華姓觀察到6人(28%)共同擁有一個單倍型，且該單倍型並未出現在其他九個姓氏組和台灣隨機姓氏組中，這可能表示此單倍型為華姓所獨有。所有姓氏內之單倍型分布狀態與台灣漢人隨機姓氏並沒有差異，隨著個案數的增加，分布情形就越接近。

結論 台灣漢人常見姓氏族群具有很高的Y-STR單倍型歧異度，這可能是因為姓氏歷史久遠且起源多，使姓氏與Y染色體間的連結變弱。而較少見姓氏與罕見姓氏中，因為姓氏來源較少，族群內累積之突變較少，所以找到之世系聚集(descent cluster)在該姓氏族群中所佔之比率較高，而可能應用於法醫人身鑑別實務。

Background and purpose It is a biological necessity that a son inherit the Y chromosome of his father. Since Han population follow the paternal surname system, the surname can be thought of as traits ‘linked’ to the Y chromosome. Therefore, Han males with same surname may have same or similar Y haplotypes. The aim of our study was to analyze the Y chromosomal short tandem repeats (STR) haplotypes of groups of men with same surname and to assess the actual extent of correlation between surnames and Y-STR haplotypes in Taiwanese Han. Materials and Methods We genotyped 17 Y-STR markers (DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a, DYS385b, DYS393, DYS391, DYS439, DYS635, DYS392, Y-GATA-H4, DYS437, DYS438, DYS448) in 735 unrelated male Taiwanese Han. The individuals were subdivided into 10 groups according to their surname, including most common surnames: Chen(102), Lin(107), Li(107), less common surnames: Zhou(42), Jian(29), Tang(8), Cao(8), and rare surnames: Hua(21), Yin(5), and Ruan(6). The Y-STR data of another group of unrelated male Taiwanese Han(200) sampled from general population and 367 male Taiwanese Han from FORDDAS were served as a control population. Haplotype frequencies and haplotype diversity of each group were calculated. Possible descent cluster was identified. The correlation between surname and haplotypes of each group was analyzed. Results: Among these 10 surname groups, the haplotype diversity values were from 0.9143 (Hua) to 1 (Cao, Yin and Ruan). The common surname Chen, Lin and Li have high haplotype diversity and the haplotypes of these surname groups are well distribution as the general population. The haplotype distributions of less common surnames are similar to that of the common surnames except the surname Jian. Jian group has a haplotype shared by seven persons with two one-step neighbors near this core haplotype. This Jian’s cluster include 31.03% of its group. The rare surname Hua group has relatively lower haplotype diversity and a cluster with 42.86% of its group. A particular haplotype was shared by 6 persons with three one-step neighbors, whereas this haplotype has not been identified in other surname groups. This Y-STR haplotype may be specific to men with surname Hua. The Principal Coordinate Analysis showed similar distribution of 17 Y-STR loci of 10 different surname groups and Taiwanese Han. Conclusions: Our results suggest that the origins of the common surnames in Taiwanese are heterogeneous. Many interference factors have obscured the Y-STR linkage within common surname groups. The less common and rare surname groups may have the chance to find a bigger descent cluster which has potential to be used in forensic human identification.