Allelotype analysis was done at five short tandem repeat markers (D17S855, D17S1322, D17S1323, D17S1326, and D17S1327) in or adjacent to BRCA1 on the recurrent mutation carriers.
对发现携带有相同突变的个体选取5个与BRCA1基因连锁的标记（D17S855、D17S1322、D17S1323、D17S1326和D17S1327）进行单倍型分析。
![DNA strand slippage during replication of an STR locus. Boxes symbolize repetitive DNA units. Arrows indicate the direction in which a new DNA strand (white boxes) is being replicated from the template strand (black boxes). Three situations during DNA replication are depicted. (a) Replication of the STR locus has proceeded without a mutation. (b) Replication of the STR locus has led to a gain of one unit owing to a loop in the new strand; the aberrant loop is stabilized by flanking units complementary to the opposite strand. (c) Replication of the STR locus has led to a loss of one unit owing to a loop in the template strand. (Forster et al. 2015)](/Images/godic/202502/10/STR-Slippage_Dr.Peter_Forster0540.jpg")
![A partial human STR profile obtained using the Applied Biosystems Identifiler kit](/Images/godic/202502/10/Str_profile0540.jpg")