Add traces to Plotly Graph in a for loop, only shows the last trace in loop

Question

I am trying to add traces for each of the synonym names of the a searched human gene, but when I search a gene in the app it only shows the searched gene and the last gene in the synonyms list. I'm not sure how to be able to see all the synonym genes plotted in the same color along with the searched gene?

Current code:

import pandas as pd
import dash
import dash_core_components as dcc
import dash_html_components as html
import plotly.graph_objects as go
from dash.dependencies import Input, Output
import plotly.express as px
import plotly.io as pio
from plotly.tools import make_subplots
pd.options.plotting.backend = "plotly"
pio.renderers.default = "browser"


try:
        app = dash.Dash(__name__)
    
        app.layout = html.Div([
            html.Label('Search Box'),
        dcc.Input(id="search_gene", 
                  type="text",
                  value = '',
                  placeholder="Type a human gene name",
                  debounce = True,
                  minLength = 0, maxLength = 50,
                  autoComplete='on',
                  size='40'),            
        html.Br(),
        html.Div([
            html.Div([
            dcc.Graph(id='mygraph')])])    
        ])           
                              
        @app.callback(
            Output('mygraph', 'figure'),
            [Input('search_gene', 'value')])
        def update_output(search_gene):
            df = pd.read_csv('list_out.txt', sep = '\t', dtype=str)
            df = df.transpose().reset_index().rename(columns={'index':'Date'})
            new_header = df.iloc[0] 
            df = df[1:] 
            df.columns = new_header
            df = df.iloc[0:600]
            df = df.set_index('Date')

            
            lookup_df = pd.read_csv('Gene_Lookup.csv', dtype = str)
            link = lookup_df.set_index('Approved_Symbol').Linked_Genes.str.split('|').to_dict()
            
            link_date = lookup_df.set_index('Approved_Symbol').Date_Name_Changed.to_dict()
            
            
            if search_gene:
                search_gene = (search_gene).upper()
                syns = link[search_gene]
                date = link_date[search_gene]
                
                
                trace1 = go.Scatter(x=df.index, 
                                    y = df[search_gene], 
                                    line_shape='linear', 
                                    line = dict(color='steelblue'), 
                                    name = search_gene)
               
                    
                fig = make_subplots(rows=1,subplot_titles=['Synonymous Gene Names'],
                shared_yaxes=True)
                
                fig.add_trace(trace1)
                
                for i in syns:
                    fig.append_trace(go.Scatter(x=df.index, 
                                    y = df[i], 
                                    line_shape='linear', 
                                    line = dict(color='black'), 
                                    name = i), row=1, col=1)
                
                fig.update_layout(title="Human Gene Name Occurances Per Month", xaxis_title="Date", yaxis_title="Count")
                fig.add_shape(type="line", name = 'Date Human Genome Sequenced',
                              x0='2003-4', y0= '-10', x1='2003-4', y1=100,
                              line=dict(color="lightblue",width=3))
                fig.add_shape(type="line", name = 'Date Name Changed',
                              x0=date, y0='-10', x1=date, y1=100,
                              line=dict(color="darkblue",width=3))
                    
            elif search_gene is None or len(search_gene) == 0:
                df1 = pd.read_csv('list_out1.txt', sep='\t', dtype=str)
                #df1 = df1.set_index('Date')
                fig = px.line(df1, x=df1['Date'], y=df1.columns[1:])
                fig.update_layout(title="Human Gene Name Occurances Per Month", xaxis_title="Date", yaxis_title="Count")
                
            return fig
                    
                
        if __name__ == '__main__':
            app.run_server(debug=True)

except:
    pass

The data being plotted (df):

        BNaC2 ASIC1 hBNaC2
Time                    
1971-1      0     0    0
1971-2      0     3    0
1971-3      0     0    0
2017-9      1     0    0
2017-10     0     4    0
2017-11     0     0    7
2017-12     5     0    0

The gene_lookup file:

      Approved_Symbol  ...            Linked_Genes
0              A12M1~  ...                     NaN
1             A2MRAP~  ...                     NaN
2               ASIC1  ...      ACCN2|BNaC2|hBNaC2
3               BNaC2  ...      ACCN2|ASIC1|hBNaC2
4              hBNaC2  ...       ACCN2|ASIC1|BNaC2