“Series objects are mutable and cannot be hashed” error

I am trying to get the following script to work. The input file consists of 3 columns: gene association type, gene name, and disease name.

cols = ['Gene type', 'Gene name', 'Disorder name']
no_headers = pd.read_csv('orphanet_infoneeded.csv', sep=',',header=None,names=cols)

gene_type = no_headers.iloc[1:,[0]]
gene_name = no_headers.iloc[1:,[1]]
disease_name = no_headers.iloc[1:,[2]]

query = 'Disease-causing germline mutation(s) in' ###add query as required

orph_dict = {}

for x in gene_name:
    if gene_name[x] in orph_dict:
        if gene_type[x] == query:
            orph_dict[gene_name[x]]=+ 1
        else:
            pass
    else:
        orph_dict[gene_name[x]] = 0

I keep getting an error that says:

Series objects are mutable and cannot be hashed

Any help would be dearly appreciated!