SUN-519 Kallman Syndrome in an Australian First Nations patient with Bigender Gender Identity

Abstract M. Balcerek: None. B. Nolan: None. J. MacLeod: None. Background: Australia’s First Nations (Aboriginal and Torres Strait Islander) peoples represent ∼4% of the Australian population. First Nations peoples have diverse concepts of gender identity that extend beyond typical Western binary and nonbinary constructs. They also have higher rates of mental illness and socioeconomic disadvantage compared to non-indigenous Australians, with similar health disparities experienced by transgender, gender diverse and nonbinary Australians. Clinical case: A 57-year-old Australian Aboriginal patient (recorded male at birth) was referred to the Gender Service for evaluation of gender incongruence by their primary care provider. The patient described negative health care experiences due to misgendering. They disclosed a bigender gender identity (both male and female), an identity embraced and celebrated in their culture. There was no dysphoria relating to their sex recorded at birth, nor physical characteristics. Their main concern was osteoporosis management, and they were subsequently referred to Endocrinology. The presence of hypogonadotrophic hypogonadism and anosmia previously prompted karyotyping, confirming a diagnosis of Kallman Syndrome. Their medical history included type 2 diabetes mellitus (T2DM) with suboptimal glycaemic control, microvascular/macrovascular complications, and autonomic dysfunction. Cardiovascular risk factors included hypertension, dyslipidaemia, and class III obesity. Osteoporosis was diagnosed in the setting of multiple previous fragility fractures. Medications included Sitagliptin/Metformin (50/1000mg bd), Insulin Aspart/Insulin Aspart Protamine (30/70 units/mL) 80 units bd, Perindopril/Amlodipine (10/10mg daily), Simvastatin 40mg daily and Pregabalin 100mg daily. They were previously treated with testosterone for pubertal induction; however, this was self-ceased at age 40 years due to perceived lack of benefit. They were not on hormonal therapy, with low serum total testosterone and estradiol concentrations (1.1 nmol/L and 72 pmol/L via immunoassay respectively), and inappropriately low gonadotrophins (FSH 0.1, LH <0.1 IU/L). Transdermal estradiol 0.1% (2mg daily) was commenced to target an estradiol concentration >200 pmol/L for bone health, rather than for feminisation. Their diabetes therapy was intensified, and they were counselled on cardiovascular risk modification. Discussion: Our case is the first report of an Australian First Nations person with Kallman syndrome and bigender gender identity, treated with both masculinising and feminising hormone therapy across their lifetime. Important medical considerations include the physiologic effect of masculinising and feminising hormones on their T2DM, cardiometabolic risk factors and osteoporosis. Culturally responsive gender affirming health care and trauma-informed practice were also essential. Sunday, June 2, 2024