A distinct clinical phenotype in two siblings with X-linked adrenoleukodystrophy


Kutbay N., Ozbek M. N., Yurekli B. S., DEMİRBİLEK H.

Neuroendocrinology Letters, vol.40, no.1, pp.36-40, 2019 (SCI-Expanded, Scopus) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 40 Issue: 1
  • Publication Date: 2019
  • Journal Name: Neuroendocrinology Letters
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.36-40
  • Keywords: X-linked adrenoleukodystrophy (X-ALD), Very Long-Chain Fatty Acids (VLCFA), Bone Marrow Transplantation (BMT), Primary adrenal insufficiency, ATP Binding Cassette Subfamily D Member 1 (ABCD1)
  • Manisa Celal Bayar University Affiliated: Yes

Abstract

OBJECTIVES: X-linked adrenoleukodystrophy(X-ALD) is a rare X-linked recessive metabolic disorder. The mutations in the ATP Binding Cassette Subfamily D Member 1 (ABCD1) gene account for the underlying molecular mechanism. Herein, we present two siblings with X-ALD due to a missense, presumably identical, ABCD1 mutation, who had extremely distinct clinical phenotypes. MATERIAL AND METHODS: Patient 1 (6y/o) was admitted with primary adrenal insufficiency (PAI). His VLCFA analysis and cranial MRI suggested the diagnosis of X-ALD with no cranial involvement. Although the PAI was successfully managed using hydrocortisone replacement therapy, during follow-up he was admitted with the complaints of perception impairment, seizures, loss of vision and deafness suggesting cranial involvement which was not able to be recovered despite intensive supportive therapies; in the end patient died. Patient 2 (21y/o) had mild symptoms of PAI with no organ manifestation. He was undertaken to a molecular genetics analysis for ABCD1 gene due to history of his brother. His VLCFA analysis revealed mildly elevated C26, C22 and C26/C22 ratio suggesting ALD diagnosis. However, his cranial imaging and other results were within normal limits. CONCLUSION: Two siblings with X-ALD due to presumably an identical, missense ABCD1 mutation and distinct clinical phenotype have confirmed the lack of phenotype-genotype correlation and proved the essential role of molecular genetics analysis in the early diagnosis. It is crucial to follow up for the development of cranial involvement and decide a bone marrow transplantation which is the only option that can prevent the progression of the disease, thus extend the lifespan.