What is Kallmann Syndrome?

A genetic condition where the hypothalamus doesn't produce GnRH (Gonadotropin-Releasing Hormone), the signal that starts puberty. It is a form of Hypogonadotropic Hypogonadism.

Key Feature:

Anosmia: Absent or severely reduced sense of smell. This is because GnRH neurons and olfactory neurons develop together in the embryo.

Symptoms:

• Delayed or Absent Puberty: No breast development (girls) or testicular enlargement (boys) by age 13-14.
• Infertility.
• Micropenis in boys (if severe).
• Associated Features: Cleft lip/palate, hearing loss, kidney abnormalities, or synkinesia (mirror movements of hands).

Diagnosis:

• Low LH, FSH, Testosterone/Estrogen.
• MRI: May show absent or small olfactory bulbs.
• Genetic Testing: Multiple genes can cause it (KAL1, FGFR1, etc.).

Treatment:

• Hormone Replacement: Testosterone (boys) or Estrogen + Progesterone (girls) to induce puberty and maintain secondary sex characteristics.
• Fertility: Pulsatile GnRH pump or injectable gonadotropins (LH/FSH) can stimulate the testes/ovaries to produce sperm/eggs.