Newborn screening for adrenoleukodystrophy (ALD), including the monitoring and treatment of poor function of the adrenal glands, can prevent the development of potential life-threatening symptoms, a case series study reports.
During childhood, boys with ALD can develop cerebral ALD and primary adrenal insufficiency. This occurs when the adrenal glands, located above the kidneys, fail to produce enough vital hormones, such as sex hormones and cortisol.
Primary adrenal insufficiency is often a missed diagnosis, with symptoms often attributed to other more common conditions. An adrenocorticotropic hormone (ACTH) stimulation test can be used to identify adrenal gland dysfunction.
Detecting these conditions before the onset of symptoms is vital for timely, lifesaving therapies. Thus, in several U.S. states, newborn screening programs include blood tests that allow the early diagnosis of ALD.
This case-series report describes two cases where primary adrenal insufficiency was evident during early infancy. In both cases, ALD was determined by newborn screening that showed increased levels of very long chain fatty acids (VLCFAs) and the presence of a mutation in the ABCD1 gene.
ALD is caused by mutations in the ABCD1 gene, which result in excess accumulation of very long chain fatty acids, especially in the brain and adrenal glands. That leads to progressive damage to the brain and the hormone-producing adrenal glands.
The first case was of a 7-week-old boy diagnosed with ALD. Initially, the boy showed no symptoms of adrenal insufficiency. However, at 4.5 months, he showed hyperpigmentation and low cortisol levels. The boy began corticosteroid treatment, specifically hydrocortisone.
However, he still showed hyperpigmentation, low cortisol levels, and increasing ACTH levels. He was then submitted to daily corticosteroid replacement therapy at 11 months of age. With the exception of hyperpigmentation, no other noticeable symptoms of adrenal insufficiency were detected, and magnetic resonance imaging (MRI) scans at 12 months of age did not show evidence of cerebral ALD.
The second case was of a 17-month-old boy with ALD. Tests starting from 5 weeks of age showed borderline cortisol levels and increasing ACTH levels, resulting in the patient being treated with hydrocortisone.
Tests at 16.5 months of age showed low cortisol levels and increased ACTH levels; therefore, the patient was treated with daily maintenance hydrocortisone. At 17 months, with the exception of a bronzed skin tone, no other symptoms of adrenal insufficiency were identified. However, MRI scans at 25 months of age did identify signs indicative of cerebral ALD.
Overall, both case studies exemplify the benefits of ALD newborn screening to identify adrenal insufficiency before symptoms appear, thus allowing the introduction of timely therapies. Altered cortisol and ACTH levels often occur before other noticeable symptoms are identified, and adrenal insufficiency often occurs before the neurological symptoms.
“The clinical course of these patients supports the inclusion of ALD on newborn screening panels, as well as the need for adrenal dysfunction surveillance to start at diagnosis with follow-up testing every 3-4 months in the first two years, as recommended by the Pediatric Endocrine Society published guidance,” researchers stated.
“Prospective studies of children identified with ALD by newborn screening are necessary to better understand the natural development of ALD-related adrenal insufficiency, and to predict those at highest risk for adrenal insufficiency during infancy,” the team said.