Novel ABCD1 variant causes phenotype of adrenomyeloneuropathy with cerebral involvement in Ukrainian siblings: first adult hematopoietic stem cell transplantation for ALD in Ukraine: a case report

Abstract

Background: This article presents a case study of two white male siblings of 24 and 31 years of age of self-reported Ukrainian ethnicity diagnosed with adrenomyeloneuropathy (AMN) associated with a novel splice site mutation in the ABCD1 gene. AMN represents a form of X-linked adrenoleukodystrophy (X-ALD) characterized by demyelination of the spinal cord and peripheral nerves. The case also presents the first adult haematopoietic stem cell transplant (HSCT) for adrenomyeloneuropathy in Ukraine. The rarity of this mutation and its cerebral involvement and the treatment make this case noteworthy and underscore the significance of reporting it to contribute to the existing medical knowledge.

Case presentation: The patients of 24 and 31 years initially exhibited progressive gait disturbance, lower extremity pain, and urinary incontinence, with the older sibling experiencing more advanced symptoms of speech, hearing, and vision disturbances. A comprehensive genetic analysis identified an unreported splice site mutation in exon 3 of the ABCD1 gene, leading to the manifestation of AMN. The inheritance pattern was consistent with X-linked recessive transmission. The article also outlines the clinical features, magnetic resonance imaging (MRI), and nerve conduction study (NCS) findings. Moreover, it discusses the genetic profile of the affected individuals and female carriers within the family. The younger sibling underwent HSCT, which was complicated by mediastinal lymph node and lung tuberculosis, adding to the complexity of managing adult ALD patients.

Conclusions: This report emphasizes the importance of genetic testing in diagnosing and comprehending the underlying mechanisms of rare genetic disorders, such as AMN with cerebral involvement. The identification of a novel splice site mutation expands our understanding of the genetic landscape of this condition. Additionally, the challenges and complications encountered during the hematopoietic stem cell transplant procedure underscore the need for cautious consideration and personalized approaches in adult ALD patients.

Keywords: ABCD1 gene; Adrenoleukodystrophy; Adrenomyeloneuropathy; Hematopoietic stem cell transplant; Novel variant.

Fig. 1

Pedigree of the extended family with the novel c.1224G > A, Glu408 = mutation in ABCD1 gene

Fig. 2

Pre-HCT MRI, 24 y o proband, T2, Flair hyperintensities of cortico-spinal tracts at various levels (green arrowheads A, B, D); symmetrical bilateral signal changes at the level of medial and lateral geniculate bodies (blue arrowheads, C); diffuse spinal cord atrophy (green arrowhead, E)

Fig. 3

MRI+ 90 day post HCT. No changes comparatively to pre HCT findings (Flair hyperintensities of cortico-spinal tracts at various levels and geniculate bodies (green arrowheads A, B)