bash – Grep exact match no dash

I have a list of genes like this one saved on a variable:

NOL6
NPPC
NPRL2
NRG1
NT5C1B
NUDT19
OSER1
PAEP
PARD3
PCDHA4

I want to grep all these genes at another list:

chr3 NPRL2
chr5 NT5C1B
chr5 NT5C1B-RDH14
chr2 NUDT19
chr21 ABC

I tried this:

grep -w "^$genes$" list.txt

The problem is that it returns to me genes with a dash too:

    chr3 NPRL2
    chr5 NT5C1B
    chr5 NT5C1B-RDH14
    chr2 NUDT19

I tried to use -x but it doesn’t work as the complete line doesn’t match because of the first column.