Awk: duplicate column and print remaining as is

Shell Programming and Scripting
1

Hello there

I'd like to make a copy of 2nd column and have it printed in place of column 1. Remaining columns are needed as it.

test data:

ProbeSet        GeneSymbol      X22565285     X22566285
ILMN_1050008    MYOCD   6.577   7.395
ILMN_1050014    GPRC6A  6.595   6.668
ILMN_1050017    FLJ38281        6.699   6.897
ILMN_1050019    LOC390084       7.41    7.839
ILMN_1050020    IMUP    6.777   7.74

awk '{printf $2"\t" ; for (i=2; i<=NF ;i++)  { print $i"\t"  } }'  file.txt

Bad output:

GeneSymbol      GeneSymbol
X22565285
X22566285
MYOCD   MYOCD
6.577
7.395
GPRC6A  GPRC6A
6.595
6.668
FLJ38281        FLJ38281
6.699
6.897
LOC390084       LOC390084
7.41
7.839
IMUP    IMUP
6.777
7.74

Rather I need output like:

GeneSymbol GeneSymbol X22565285 X22566285
MYOCD   MYOCD 6.577 7.395
2 
$ awk '$1=$2'  file
GeneSymbol GeneSymbol X22565285 X22566285
MYOCD MYOCD 6.577 7.395
GPRC6A GPRC6A 6.595 6.668

or

$ awk '$1=$2' OFS="\t" file
GeneSymbol	GeneSymbol	X22565285	X22566285
MYOCD	MYOCD	6.577	7.395
GPRC6A	GPRC6A	6.595	6.668
3

oh!

Thank you