Most common cause of delayed pubey in males is: (A) Kallaman syndrome, (B) Klienfelter syndrome, (C) Constitutional, (D) Prader-willi syndrome
Answer is C. Constitutional delay in growth and pubey is the most common cause of delayed pubey in boys.These boys have growth retardation and delayed bone age.Family history of delayed pubey is present.Gonadotropin levels are prepubeal similar to hypgonadotropic hypogonadism. Reference : OP Ghai ,eseential paediatrics 8 th edition, page no 538 .