X Chromosome Inactivation in Carriers of Fabry Disease: Review and Meta-Analysis

Anderson-Fabry disease is an X-linked inborn error of glycosphingolipid catabolism caused by a deficiency of α-galactosidase A. The incidence ranges between 1: 40,000 and 1:117,000 of live male births. In Italy, an estimate of incidence is available only for the north-western Italy, where it is of approximately 1:4000. Clinical symptoms include angiokeratomas, corneal dystrophy, and neurological, cardiac and kidney involvement. The prevalence of symptomatic female carriers is about 70%, and in some cases, they can exhibit a severe phenotype. Previous studies suggest a correlation between skewed X chromosome inactivation and symptoms in carriers of X-linked disease, including Fabry disease. In this review, we briefly summarize the disease, focusing on the clinical symptoms of carriers and analysis of the studies so far published in regards to X chromosome inactivation pattern, and manifesting Fabry carriers. Out of 151 records identified, only five reported the correlation between the analysis of XCI in leukocytes and the related phenotype in Fabry carriers, in particular evaluating the Mainz Severity Score Index or cardiac involvement. The meta-analysis did not show any correlation between MSSI or cardiac involvement and skewed XCI, likely because the analysis of XCI in leukocytes is not useful for predicting the phenotype in Fabry carriers.

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X-chromosome inactivation patterns in females with Fabry disease examined by both ultra-deep RNA sequencing and methylation-dependent assay

10.21203/rs.3.rs-100840/v1 ◽

2020 ◽

Author(s):

Rini Rossanti ◽

Kandai Nozu ◽

Atsushi Fukunaga ◽

China Nagano ◽

Tomoko Horinouchi ◽

...

Keyword(s):

Fabry Disease ◽

Rna Sequencing ◽

X Chromosome ◽

Clinical Symptoms ◽

Wide Spectrum ◽

X Chromosome Inactivation ◽

Chromosome Inactivation ◽

Severe Phenotype ◽

Female Patients ◽

Pathogenic Variants

Abstract Background: Fabry disease is an X-linked inherited lysosomal storage disorder related to GLA mutations, gene encoding α-galactosidase A. In general, males has severe phenotype, while females has a wide spectrum of sign and symptoms, from asymptomatic to a more classical profile including cardiac, renal, and cerebrovascular manifestations. This variability has been assumed to be derived from organ-dependent skewed X-chromosome inactivation (XCI) patterns in each female patient. Some previous studies examined this correlation using the classical methylation-dependent method; however, conflicting results were obtained. This study was established to determine the existence of skewed XCI in nine females with heterozygous pathogenic variants in the GLA gene and its relationship to the phenotypes. Methods: We present five female patients from one family and four individual female patients with Fabry disease. In all cases, heterozygous pathogenic variants in the GLA gene were detected. The X-chromosome inactivation patterns in peripheral blood leukocytes and cells of urine sediment were determined by both classical methylation-dependent HUMARA assay and ultra-deep RNA sequencing, the latter being a method that we recently developed. Results: Among all cases, skewed XCI resulting in predominant inactivation of the normal allele was observed only in one individual case with a severe phenotype. In the other eight cases, no skewing was observed, even among cases with severe phenotypes. Conclusions: We conclude that skewed XCI could explain the severity of Fabry disease in only a limited number of female cases and is not the main factor in the onset of various clinical symptoms in females with Fabry disease.

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X-Linked Emery–Dreifuss Muscular Dystrophy: Study Of X-Chromosome Inactivation and Its Relation with Clinical Phenotypes in Female Carriers

Genes ◽

10.3390/genes10110919 ◽

2019 ◽

Vol 10 (11) ◽

pp. 919 ◽

Cited By ~ 1

Author(s):

Viggiano ◽

Madej-Pilarczyk ◽

Carboni ◽

Picillo ◽

Ergoli ◽

...

Keyword(s):

Muscular Dystrophy ◽

X Chromosome ◽

Clinical Symptoms ◽

Fibrous Tissue ◽

X Chromosome Inactivation ◽

Chromosome Inactivation ◽

Cardiac Conduction ◽

Asymptomatic Carriers ◽

Cardiac Symptoms ◽

Female Carriers

X-linked Emery–Dreifuss muscular dystrophy (EDMD1) affects approximately 1:100,000 male births. Female carriers are usually asymptomatic but, in some cases, they may present clinical symptoms after age 50 at cardiac level, especially in the form of conduction tissue anomalies. The aim of this study was to evaluate the relation between heart involvement in symptomatic EDMD1 carriers and the X-chromosome inactivation (XCI) pattern. The XCI pattern was determined on the lymphocytes of 30 symptomatic and asymptomatic EDMD1 female carriers—25 familial and 5 sporadic cases—seeking genetic advice using the androgen receptor (AR) methylation-based assay. Carriers were subdivided according to whether they were above or below 50 years of age. A variance analysis was performed to compare the XCI pattern between symptomatic and asymptomatic carriers. The results show that 20% of EDMD1 carriers had cardiac symptoms, and that 50% of these were ≥50 years of age. The XCI pattern was similar in both symptomatic and asymptomatic carriers. Conclusions: Arrhythmias in EDMD1 carriers poorly correlate on lymphocytes to a skewed XCI, probably due to (a) the different embryological origin of cardiac conduction tissue compared to lymphocytes or (b) the preferential loss of atrial cells replaced by fibrous tissue.

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