Endocrine Abstracts

JOINT3435

Introduction: Kallmann-Morsier syndrome is a rare genetic condition characterized by the association of hypogonadotropic hypogonadism (HH) with anosmia or hyposmia. This condition results from a defect in the embryonic migration of GnRH-producing neurons and olfactory neurons. Diagnosis is often delayed due to the significant variability in clinical manifestations.

Case Report: We present the case of a 17-year-old single female patient who consulted for primary amenorrhea. The medical history revealed anosmia present since childhood, with a family history of anosmia reported in her father. Clinical examination revealed normal development of secondary sexual characteristics, corresponding to Tanner stage S3P3. Biological assessments showed hypogonadotropic hypogonadism, with low LH and FSH levels, indicating dysfunction of the hypothalamic-pituitary axis. Paraclinical evaluations revealed:.

- A normal breast ultrasound,.

- A normal transthoracic echocardiogram,.

- An MRI of the olfactory bulbs showing complete agenesis of the left olfactory bulb and hypoplasia of the right olfactory bulb, thereby confirming the diagnosis of Kallmann syndrome. The treatment implemented was progressive hormone replacement therapy. Estradiol was gradually introduced over two years to promote the development of secondary sexual characteristics and ensure bone health. Subsequently, progesterone was added to simulate a physiological menstrual cycle.

Discussion: Kallmann syndrome was first described in 1944 by Franz Josef Kallmann, a German-born geneticist who emigrated to the United States. This condition results from a defect in the embryonic migration of GnRH-producing neurons and olfactory neurons, caused by genetic mutations, particularly in the KAL1, FGFR1, and PROKR2 genes. Although rare, this syndrome should be considered in any patient presenting with primary amenorrhea associated with hypogonadotropic hypogonadism and anosmia or hyposmia.

Conclusion: This case highlights the importance of suspecting Kallmann syndrome in adolescent girls presenting with primary amenorrhea accompanied by anosmia. Early and appropriate management, including hormone replacement therapy, optimizes pubertal development, improves bone health, and ensures a better quality of life.