SAT281 Screening For Adrenocortical Insufficiency In Patients With X-linked Adrenoleukodystrophy

Disclosure: J. Berquist: None. R.N. Kiani: None. M.P. Wahl: None. Background: A 41-year-old male initially presented to neurology clinic for complaints of poor balance, lower extremity weakness, and numbness. He previously had exam findings of lower extremity spasticity and hyperreflexia, distal vibratory loss, positive Romberg, and difficulty with Tandem gait. His symptoms had been progressive following an ankle sprain 8 years earlier and he was treated with physical therapy and baclofen. He is highly active otherwise and enjoys rock climbing, which was difficult to do given his symptoms. Clinical Case: Genetic screening was performed to evaluate for hereditary spastic paraparesis, which resulted positive for a mutation in the ABCD1 gene with a p.Lys336Glu mutation of uncertain significance. Interestingly, this ABDC1 variant was not detected in submitted maternal sample, hence patient’s mutation likely occurred de novo. This variant is not established in population databases (gnomAD no frequency) but has been observed in at least one individual with clinical features of adrenomyeloneuropathy. X-linked adrenoleukodystrophy causes impairment of beta oxidation that leads to accumulation of saturated very long chain fatty acids (VFLA) in multiple tissues. There are many clinical phenotypes, but they are hallmarked by neurologic signs and symptoms. Although neurologic symptoms can often develop in childhood, they can be delayed and present in adulthood, as can adrenal insufficiency (AI). However, males are overwhelmingly likely to develop adrenocortical insufficiency compared to females. Our patient presented with a BMI of 22.94, HR 50 bpm, and blood pressure 120/76; reflecting his active lifestyle. Recent electrolytes were within normal limits, AM cortisol was 13.0, and ACTH 544.0 Given the elevated ACTH and known cause of adrenal insufficiency, we proceeded with ACTH stimulation test. Peak cortisol resulted at 13.1 (at 60 minutes) and he was started on replacement glucocorticoid therapy per body-surface area. Upon further literature review, patients can also develop loss of mineralocorticoid production. Renin and aldosterone were ordered and were both within normal limits. Conclusion: Males with adrenoleukodystrophy are at a much higher risk of developing adrenal insufficiency (AI) compared to females. Additionally, AI will often develop later in life, so a low threshold for screening should be present for the endocrinologist. Mineralocorticoid deficiency can also develop, although not as commonly. Loss of adrenal function can lead to patient demise, and therefore adrenal function needs to be closely evaluated in people with leukodystrophy. Presentation: Saturday, June 17, 2023