Q.t (A,B) means translocation fr. A to B or B to A or what?

[Aumsai]

Hi,
I have a confusion on translocation. My question is, For eg, if there is t(A,B) ,does this mean-
1. gene on chr. A translocates to gene on chr B? ,or,
2. gene on chr B translocates to gene on chr A?

I came across the following translocations when I was reading WBC disorders which really made me confused

1. In acute promyelocytic leukemia , there is t ( 15,17) which involves translocation of the retinoic acid receptor (RAR) on chr. 17 to chr.15
2.In follicular lymphoma, t (14,18) occurs in which Bcl 2 on chr. 18 translocates to the Ig heavy chain locus on chr. 14
3.. In mantle cell lymphoma t(11,14) takes place in which Cyclin D1 gene on chromosome 11 translocates to Ig heavy chain locus on chr. 14.

Can anyone pls help me out to dispel this confusion.Thanks.

[datson]

It could be either. You write the numbers in ascending order.
So t(8;21) not t(21;8)

[Aumsai]

Ok, got it. Thanks datson.