Endocrine Abstracts

Introduction: Kallmann-de Morsier Syndrome is a rare genetic disorder characterized by the combination of hypogonadotropic hypogonadism and anosmia or hyposmia. It is more prevalent in males compared to females. In this case report, we present the case of an adolescent with Kallmann-de Morsier Syndrome.

Case Presentation: An 18-year-old patient was referred to our endocrinology clinic by gynecologists for the investigation of pubertal delay. The patient’s parents were not consanguineous. There were not a family history of pubertal delay or infertility. The patient has a history of epilepsy since childhood, managed with medication, and reports a long-standing hyposmia. Upon examination, the patient exhibited facial dysmorphia, including a broad forehead, protruding ears, a flat nose, and full lips. She was at Tanner stage S2P4A2. Neurological examination revealed cerebellar syndrome. Hormonal exploration identified hypogonadotropic hypogonadism and lactotroph insufficiency. Corticotrope and thyrotrope insufficiency were ruled out. Pelvic ultrasound showed an underdeveloped uterus with normal ovaries. The Karyotype was 46 XX. Hypothalamus-hypophysis and olfactory bulb MRI revealed agenesis of the olfactory bulbs, strongly suggesting Kallmann-de Morsier Syndrome. Renal ultrasound showed no anomalies. Hormonal treatment, based on estrogen, was initiated until breast development was complete. Subsequently, a progestin was added to induce menarche.

Discussion: Kallmann-de Morsier Syndrome (KS) or olfacto-genital dysplasia results from prenatal anomalies in the migration of GnRH neurons, often associated with olfactory bulb atrophy. This disease is four times less frequent in females. Primary amenorrhea is the presenting circumstance in over 90% of cases in females. Breast development varies. Diagnosis is confirmed by hypoplasia of olfactory bulbs on MRI. Besides clinical features, it is crucial to explore associated conditions such as renal or dental agenesis, cerebellar syndrome (as observed in this case), cleft lip/palate, or synkinesias. The sporadic form is more common than the familial form, and in 60-65% of patients, no mutations are identified.

Conclusion: Early diagnosis of Kallmann-de Morsier Syndrome is crucial to mitigate the organic and psychological impact of pubertal delay. The clinical and radiological context plays a pivotal role in diagnosis, as genetic studies are often inconclusive. Hormonal treatment facilitates puberty, and long-term fertility can be achieved

References: 1. H. Marhari, F. Z. Chahdi Ouazzani, H. E. Ouahabi, et L. Bouguenouch, « Le syndrome de Kallmann-de Morsier: à propos de trois cas », Pan Afr. Med. J., vol. 33, p. 221, juill. 2019. 2. I. U.-T. D. RESERVES, « Orphanet: Syndrome de Kallmann ». Consulté le: 21 janvier 2024.