Hossain MA, Wu C, Yanagisawa H, Miyajima T, Akiyama K, Eto Y. Future clinical and biochemical predictions of Fabry disease in females by methylation studies of the
GLA gene.
Mol Genet Metab Rep 2019;
20:100497. [PMID:
31372342 PMCID:
PMC6661284 DOI:
10.1016/j.ymgmr.2019.100497]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/17/2019] [Accepted: 07/17/2019] [Indexed: 12/29/2022] Open
Abstract
Fabry disease is an X-linked lysosomal storage disorder caused by a deficiency of α-galactosidase A (α-gal A). The clinical variability of the phenotypes of Fabry disease in females is still poorly understood. The degree of aberrant methylation of non-mutated alleles is thought to have significant effects on X-chromosome inactivation (XCI). We previously reported that one heterozygous Fabry female showing classical phenotypes had complete methylation of the non-mutated allele of the GLA gene. In this report, we summarized 36 heterozygous females with a clinical severity score based on the FAbry STabilization indEX (FASTEX). We measured their α-gal A activity and plasma/ serum globotriaosylsphingosine (lyso-Gb3) accumulation and performed electron microscopy of skin biopsies. We analyzed the methylation-sensitive restriction enzyme sites throughout the GLA gene, including the 5’UTR, and found a single SacII site and multiple HhaI and HpaII sites aggregated in exon 1 and the 5’UTR. One HpaII sequence in exon 7 was also detected as a methylation-sensitive site. With methylation-sensitive restriction enzymes, methylated and non-methylated alleles could be separated, and the ratio of the methylation was quantified. We found a clear correlation between the severity of the phenotype and lyso-Gb3 accumulation for heterozygous Fabry disease in females. Methylation of the non-mutated allele was also proportionately correlated to the clinical severity score measured by FASTEX.
We summarized 36 heterozygous Japanese Fabry females with their clinical severity score.
We had detected methylation-sensitive restriction enzyme sites in exon 7 along with exon 1 and 5`UTR.
A clear correlation of patients’ FASTEX scores, sphingolipids accumulations and dysmethylation of the GLA gene was detected.
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