I am using Tabular to make a simple table. For three columns, my table displayed fine. When I added a fourth column, the horizontal lines stopped reaching all the way across my table. I also have a little bit of horizontal line that sticks out on the left side of the table. What went wrong with my table?
\begin{tabular*}{0.75\textwidth}{@{\extracolsep{\fill } } | l | c | c | c || }
\hline
\textbf{GENE} & \textbf{Allele of interest} & \textbf{Outcomes} & \textbf{Dominance} \\
\hline \hline
MAOA & 2.5, 3, 5 & Agression & Recessive, Sex-selective \\ \hline
DAT1 & 10R & ADHD & hz. disadvantage \\ \hline
DRD4 & 7R & ADHD & - \\ \hline
5-HTT & 14 (s) & Negative Thoughts, Fear & Dominant \\ \hline
TRI & S & Depression & Codominant \\ \hline
DRD2 & A & Alcoholism & Dominant \\ \hline
DRD5 & 148 & ADHD & - \\ \hline
S000005 & A & Stress & - \\ \hline
S000006 & T & ADHD & - \\ \hline
MAOCA1 & 115+ & Alcoholism & Sex selective \\ \hline
\end{tabular*}
.75\textwidth
, while the actual table is much wider. Do you really need this constrain?