X-LINKED ADRENOLEUKODYSTROPHY IN BRAZIL: A CASE SERIES

The Clinical Spectrum of Adrenoleukodystrophy at a Portuguese Tertiary Hospital: Case Series and Review of Literature

Adrenoleukodystrophy, a rare genetic disease associated with the X chromosome (X-ALD - X-linked adrenoleukodystrophy), predominantly affects males and stems from mutations in the ABCD1 gene, responsible for transporting very long chain fatty acids (VLCFA) into peroxisomes. It leads to adrenal insufficiency (AI) and axonal demyelination. In males, the phenotype varies from isolated adrenocortical insufficiency and progressive myelopathy to cerebral adrenoleukodystrophy (CALD). The aim of this case series is to characterize patients with different clinical presentations of X-ALD with follow-up at a tertiary Portuguese hospital. All four patients were males, and the median age at the diagnosis was 5 years. Three patients were diagnosed through family screening, with the oldest already displaying hyperpigmentation. Two distinct forms were identified: adolescent CALD (25%) and isolated primary adrenal insufficiency (75%). Analytical studies revealed elevated plasma VLCFA levels in all cases, and genetic analysis demonstrated two different mutations in the ABCD1 gene. This disorder requires early diagnosis for improved prognosis. Screening male children with primary AIfor X-ALD using a VLCFA panel should be considered, particularly after ruling out the most common causes or when learning difficulties are evident. Genetic confirmation of the diagnosis is essential, enabling genetic counseling, family planning, and preimplantation genetic diagnosis.

Pediatric adrenal insufficiency: thirty years experience at a Portuguese hospital

BACKGROUND

Adrenal insufficiency (AI) is a life-threatening condition caused by an impaired secretion of the adrenal glucocorticoid and mineralocorticoid hormones. It comprises a heterogeneous group of primary, secondary and acquired disorders. Presentation differs according to the child's age, but it usually presents with nonspecific and insidious symptoms and signs. The main purpose of this study was to describe and compare patients with primary or secondary AI.

METHODS

Retrospective analysis of all patients with adrenal insufficiency followed at the Pediatric Endocrinology Unit in a tertiary care Portuguese hospital over the last 30 years. Data on family history, age at the first manifestation and at etiological diagnosis, and clinical presentation (symptoms, signs and laboratory evaluation) was gathered for all patients.

RESULTS

Twenty-eight patients with AI were included; 67.9% were male, with a median (25th-75th percentile, P25-P75) age of 1 (0.5-36) month at the first presentation. The principal diagnostic categories were panhypopituitarism (42.9%) and congenital adrenal hyperplasia (25%). The most frequent manifestations (75%) were vomiting and weight loss. They were followed for a median (P25-P75) period of 3.5 (0.6-15.5) years. In respect to neurodevelopmental delay and learning difficulties, they were more common in the secondary AI group.

CONCLUSIONS

Despite medical advances, the diagnosis and management of AI remains a challenge, particularly in the pediatric population, and clinicians must have a high index of suspicion. An early identification of AI can prevent a potential lethal outcome, which may result from severe cardiovascular and hemodynamic instability.