The two most common forms of X-linked adrenoleukodystrophy (X-ALD), the childhood cerebral form (CCER) and the adult form, adrenomyeloneuropathy (AMN), arise from the same mutations in the X-ALD gene at Xq28.
ABCD1 mutations lead to a variety of phenotypes, including cerebral X-ALD and adrenomyeloneuropathy (AMN) in affected males and 80% of carrier females.
The nearly complete novel spectrum of ALD gene mutations identified has revealed no obvious correlation between the type of mutation and age of AMN onset in this small series.
X-adrenoleukodystrophy (X-ALD) is a complex disease where inactivation of ABCD1 gene results in clinically diverse phenotypes, the fatal disorder of cerebral ALD (cALD) or a milder disorder of adrenomyeloneuropathy (AMN).
The default manifestation of mutations in ABCD1 is adrenomyeloneuropathy, a slowly progressive dying-back axonopathy affecting both ascending and descending spinal cord tracts as well as in some cases, a peripheral neuropathy.
X-Adrenoleukodystrophy (X-ALD) and its adult-onset, most prevalent variant adrenomyeloneuropathy (AMN) are caused by mutations in the peroxisomal transporter of the very long-chain fatty acid ABCD1.
Both CCALD and AMN iPSCs normally differentiated into oligodendrocytes, the cell type primarily affected in the X-ALD brain, indicating no developmental defect due to the ABCD1 mutations.
Three unusual families were found: (1) 2 young brothers each having a PMP-22 duplication and a missense mutation in the GJB1 (Connexin-32) gene; (2) a 32-year-old woman having a PMP-22 duplication and a 1000-fold CTG repeat expansion in the DMPK gene (DM1 myotonic dystrophy); and (3) a 39-year-old man with a PMP-22 deletion and a missense mutation in the ABCD1 gene (adrenomyeloneuropathy).
It is a complex disease where the same mutation in the peroxisomal ABCD1 can lead to clinically diverse phenotypes ranging from the fatal disorder of cerebral ALD (cALD) to mild adult disorder of adrenomyeloneuropathy (AMN).
Adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN) are allelic X-chromosomal disorders of peroxisomal lipid metabolism due to mutations of the ABCD1-gene, leading, respectively, to leukoencephalopathy or myeloneuropathy in male patients.
NGS of the proband revealed a novel frameshift mutation in ABCD1 (c.1174_1178del, p.Leu392Serfs*7), bringing an end to diagnostic uncertainty by establishing the diagnosis of adrenomyeloneuropathy (AMN), the myelopathic phenotype of X-linked adrenoleukodystrophy (ALD).
Three unusual families were found: (1) 2 young brothers each having a PMP-22 duplication and a missense mutation in the GJB1 (Connexin-32) gene; (2) a 32-year-old woman having a PMP-22 duplication and a 1000-fold CTG repeat expansion in the DMPK gene (DM1 myotonic dystrophy); and (3) a 39-year-old man with a PMP-22 deletion and a missense mutation in the ABCD1 gene (adrenomyeloneuropathy).
Three unusual families were found: (1) 2 young brothers each having a PMP-22 duplication and a missense mutation in the GJB1 (Connexin-32) gene; (2) a 32-year-old woman having a PMP-22 duplication and a 1000-fold CTG repeat expansion in the DMPK gene (DM1 myotonic dystrophy); and (3) a 39-year-old man with a PMP-22 deletion and a missense mutation in the ABCD1 gene (adrenomyeloneuropathy).
There are numerous other varieties of HMSN including other autosomal dominant conditions such as HMSN-II (with nearly normal motor NCV) and several types of familial amyloid neuropathy (with specific amino acid substitutions in transthyretin); autosomal recessive conditions such as HMSN-III (Déjérine-Sottas hypertrophic neuropathy of childhood) and Refsum's disease (defect of phytanic acid metabolism); and conditions produced by mutations on the X chromosome such as X-linked HMSN, Fabry trihexoside storage disease, and adrenomyeloneuropathy.
Three unusual families were found: (1) 2 young brothers each having a PMP-22 duplication and a missense mutation in the GJB1 (Connexin-32) gene; (2) a 32-year-old woman having a PMP-22 duplication and a 1000-fold CTG repeat expansion in the DMPK gene (DM1 myotonic dystrophy); and (3) a 39-year-old man with a PMP-22 deletion and a missense mutation in the ABCD1 gene (adrenomyeloneuropathy).
X-linked adrenoleukodystrophy in Spain. Identification of 26 novel mutations in the ABCD1 gene in 80 patients. Improvement of genetic counseling in 162 relative females.