edgeR design matrix error not of full rank

Hello,

I am currently having an error when I am using the estimateDisp function on edgeR, my pheno table and design matrix looks like this:

       GROUP   AGE  GENDER
1  no_woman  26.00000  woman
2    no_man  22.18962    man
2 yes_woman  27.86650  woman
3  no_woman  21.55446  woman
4  no_woman  24.60362  woman
5  no_woman  26.47429  woman
6  no_woman  24.00000  woman
7  no_woman  29.08834  woman
8  no_woman  20.85291  woman
9   yes_man  26.28884    man
10    no_man 30.54005    man
11    no_man 25.92953    man
[...]

And that is my matrix:

Group <- y_transcripts$samples$group
Age <- y_transcripts$samples$AGE
Gender <- y_transcripts$samples$GENDER
design <- model.matrix(~0+Group+Gender+Age)
Contrasts <- makeContrasts((Groupyes_woman-Groupno_woman)-(Groupyes_man-Groupno_man),levels=colnames(design))



design
      Groupno_man Groupno_woman Groupyes_man Groupyes_woman Genderwoman      Age
    1            0             1            0              0           1 26.00000
    2            1             0            0              0           0 22.18962
    3            0             0            0              1           1 27.86650
    4            0             1            0              0           1 21.55446
    5            0             1            0              0           1 24.60362
    6            0             1            0              0           1 26.47429
    7            0             1            0              0           1 24.00000
    8            0             1            0              0           1 29.08834
    9            0             1            0              0           1 20.85291
    10           0             0            1              0           0 26.28884
    11           1             0            0              0           0 30.54005
    [....]
    attr(,"assign")
    [1] 1 1 1 1 2 3
    attr(,"contrasts")
    attr(,"contrasts")$Group
    [1] "contr.treatment"

    attr(,"contrasts")$Gender
    [1] "contr.treatment"

Afterwards I filtered by minimum expression using defaults and normalized the library size

 keep <- filterByExpr(y_transcripts, group=Group)
    y_transcripts <- y_transcripts[keep, , keep.lib.sizes=FALSE]

y_transcripts <- calcNormFactors(y_transcripts)

I got an error when using estimateDisp

y_transcripts <- estimateDisp(y_transcripts, design, robust=TRUE)

>     Error in glmFit.default(sely, design, offset = seloffset, dispersion = 0.05,  : 
>       Design matrix not of full rank.  The following coefficients not estimable:
>      Genderwoman

When I exclude Gender from the design matrix it works, I don’t know what is my mistake.