Retrospective evaluation of patients with X-linked adrenoleukodystrophy with a wide range of clinical presentations: a single center experience

J Pediatr Endocrinol Metab. 2021 Jun 23. doi: 10.1515/jpem-2021-0032. Online ahead of print.

Abstract

Objectives: X-linked adrenoleukodystrophy (X-ALD), is a peroxisomal inborn error of metabolism caused due to the loss of function variants of ABCD1 gene that leads to accumulation of very long chain fatty acids (VLCFAs) in several tissues including the neurological system. Childhood cerebral X-ALD (CCALD) is the most common and severe form of X-ALD, if left untreated. Allogenic hematopoietic stem cell transplantation (HSCT) is the only available therapy that halts neurological deterioration in CCALD. We present 12 patients with several subtypes of X-ALD that were followed-up in a single center.

Methods: Data of 12 patients diagnosed with X-ALD were documented retrospectively. Demographics, age of onset, initial symptoms, endocrine and neurological findings, VLCFA levels, neuroimaging data, molecular genetic analysis of ABCD1 gene, and disease progress were documented.

Results: Mean age of initiation of symptoms was 7.9 years and mean age of diagnosis was 10.45 years. Eight patients had the CCALD subtype, while two had the cerebral form of AMN, one had the adult form of cerebral ALD, and one patient had the Addison only phenotype. The most common initial symptoms involved the neurological system. Loes scores varied between 0 and 12. Seven patients with CCALD underwent HSCT, among them three patients died. The overall mortality rate was 25%.

Conclusions: Patients with X-ALD should be carefully followed up for cerebral findings and progression, since there is no genotype-phenotype correlation, and the clinical course cannot be predicted by family history. HSCT is the only available treatment option for patients with neurological deterioration.

Keywords: ABCD1 gene; Loes score; X linked adrenoleukodystophy; very long chain fatty acids.