Delayed Puberty in Female

Delay in onset of secondary sexual development after 13.5 years in boys → Serum gonadotropins

• Elevated → Karyotype
• Low → Growth pattern

Elevated gonadotropins — Karyotype

• Absence or abnormality of one X chromosome or mosaicism with 45,X cell line → Turner syndrome (may or may not have somatic stigmata of Turner syndrome but short stature is extremely common)
• Normal 46,XY → Primary ovarian failure–autoimmune or other etiology

Low gonadotropins — Growth pattern

• Consistently short for chronologic age but appropriate for bone age → Bone age delayed → Constitutional delay in growth and puberty
• Late-onset growth failure especially with concurrent diabetes insipidus → Signs of increased intracranial pressure or visual abnormalities → MRI → Mass → CNS tumor
• Normal without growth spurt → Sense of smell

Sense of smell pathway

• Anosmia or hyposmia → MRI → Absence of olfactory bulb and/or sulcus → Kallmann syndrome
• Normal sense of smell → Normal MRI → Isolated gonadotropin deficiency

Normal secondary sexual development with primary amenorrhea — Karyotype

• Normal → Anatomic defect or abnormality in LH pulsatility
• 46,XY → Syndrome of androgen resistance