Assuming your custom user field for the gender is named 
gender and the value is stored as e.g. 
Male, then you can use this:
	
	
	
		Code:
	
	
		{$user.username} ({$user.Profile.custom_fields.gender}, {$user.Profile.age})
	 
 
Note that the age will only show if the member has allowed it in their privacy options.