Foro de MySQL

Buenas alguin em prodra ayudar estoy tratando la bd para un formulario php y me tilda este error en el php my admin al momento de crear las tablas

#1064 - You have an error in your SQL syntax; check the manualthat corresponds to your MySQL server version for the right syntax touse near "auto increment primary key,
ptaboutservice varchar(50) null,
aboutweb varcha" at line 2

esta es la bd

create table `patients`
( `patient_id` int unsigned not null auto increment primary key,
 `ptaboutservice` varchar(50) null,
 `aboutweb` varchar(50) null,
 `phavechild` enum("y","n") null,
 `howmany_child` enum("1","2","3","4","5","more") null,
 `primary key` (patient_id),
);