Occurs when there is an extra chromosome in the 23rd pair

There are three different types of things that may occur when an extra chromosome is found in the 23rd pair. I'll give the causes and symptoms for each of three different types!

Klinefelter's Syndrome (XXY)
Cause: Occurs when there is an extra X chromosome in the 23rd pair (in males only)
Symptoms: Weak muscles, slow motor development, delay in speaking

Super Male (XYY)
Cause: Occurs when there is an extra Y chromosome in the 23rd pair
Symptoms: intellectual disabilities, increased height, behavior problems, lower intelligence/IQ, anger issues, more testosterone, usually normal appearance

Trisomy X
Cause: Extra X chromosome in 23rd pair (in females only)
Symptoms: usually asymptomatic, doesn't affect fertility, mild facial abnormalities, delayed development, tall stature when there is an extra chromosome in the 23rd pair