StudyRareStudyRare
Log in to add personal notes on this page.

A 17-year-old male has not entered puberty. He has anosmia (cannot smell). MRI shows hypoplastic olfactory bulbs.

Heterogeneous; XLR (KAL1), AD (FGFR1, FGF8), AR

  • Hypogonadotropic hypogonadism (low FSH/LH)
  • Anosmia or hyposmia (defective olfactory neuron migration)
  • Absent/delayed puberty
  • May have renal agenesis, cleft palate, hearing loss
  • Low sex steroids (testosterone/estradiol) with inappropriately low or normal LH/FSH (hypogonadotropic hypogonadism)
  • Confirmed anosmia/hyposmia distinguishes Kallmann from normosmic isolated hypogonadotropic hypogonadism; MRI shows hypoplastic or absent olfactory bulbs
  • Multigene panel testing (ANOS1/KAL1, FGFR1, FGF8, PROK2, PROKR2, CHD7, others); inheritance and associated features guide interpretation
  • Screen for associated anomalies: renal ultrasound (unilateral renal agenesis), audiometry, dental/palate exam
  • Pubertal induction and maintenance with sex steroid replacement (testosterone in males; estrogen then estrogen-progestin in females)
  • Fertility induction with gonadotropins (hCG plus FSH) or pulsatile GnRH when conception is desired
  • Bone density monitoring; long-term hormone replacement preserves bone health
  • Genetic counseling reflecting locus heterogeneity (X-linked, autosomal dominant, autosomal recessive forms)

Reference Links