TY - JOUR
T1 - Functional characterization of novel variants found in patients with suspected Fabry disease
AU - Varela-Calais, Patrícia
AU - Nicolicht, Priscila
AU - Paulo Martin, Renan
AU - Yamamoto, Joyce
AU - D'Almeida, Vânia
AU - Martins, Ana Maria
AU - Pesquero, João Bosco
N1 - Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - The deficiency or absence of the lysosomal hydrolase α-Galactosidase A results in Fabry disease (FD), a rare and underdiagnosed X-linked disorder. The symptoms caused by FD have a direct relation with the variant present in the gene coding α-Galactosidase A (GLA) and enzyme residual activity, and it can vary drastically between men and women of the same family. Here, we present four novel variants found in patients with suspicion of FD. The patients were screened for FD by enzymatic activity and/or DNA sequencing, which showed four novel GLA missense variants. To confirm the potential pathogenicity of these variants, we employed site-directed mutagenesis. GLA wild-type and mutant plasmids were transfected into mammalian cells; RNA and proteins were extracted for expression and enzymatic activity analysis. The patients presented the variants p.Ile133Asn, p.Lys140Thr, p.Lys168Gln and p.Pro323Thr in the GLA. In vitro analysis showed pathogenic potential of three variants and one tolerated variant. The variants p.Ile133Asn and p.Lys168Gln showed no residual activity and, therefore, leading to classical phenotype, and the variant p.Lys140Thr, which presented 22% of residual activity, was considered a mild variant leading to non-classical phenotype. The variant p.Pro323Thr presented 66.7% of residual activity and alone, it is not enough to cause FD.
AB - The deficiency or absence of the lysosomal hydrolase α-Galactosidase A results in Fabry disease (FD), a rare and underdiagnosed X-linked disorder. The symptoms caused by FD have a direct relation with the variant present in the gene coding α-Galactosidase A (GLA) and enzyme residual activity, and it can vary drastically between men and women of the same family. Here, we present four novel variants found in patients with suspicion of FD. The patients were screened for FD by enzymatic activity and/or DNA sequencing, which showed four novel GLA missense variants. To confirm the potential pathogenicity of these variants, we employed site-directed mutagenesis. GLA wild-type and mutant plasmids were transfected into mammalian cells; RNA and proteins were extracted for expression and enzymatic activity analysis. The patients presented the variants p.Ile133Asn, p.Lys140Thr, p.Lys168Gln and p.Pro323Thr in the GLA. In vitro analysis showed pathogenic potential of three variants and one tolerated variant. The variants p.Ile133Asn and p.Lys168Gln showed no residual activity and, therefore, leading to classical phenotype, and the variant p.Lys140Thr, which presented 22% of residual activity, was considered a mild variant leading to non-classical phenotype. The variant p.Pro323Thr presented 66.7% of residual activity and alone, it is not enough to cause FD.
KW - Fabry disease
KW - GLA gene
KW - Missense variant
KW - Novel variant
KW - α-Galactosidase A
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U2 - 10.1016/j.cca.2022.07.012
DO - 10.1016/j.cca.2022.07.012
M3 - Article
C2 - 35870541
AN - SCOPUS:85135366242
SN - 0009-8981
VL - 534
SP - 156
EP - 160
JO - Clinica Chimica Acta
JF - Clinica Chimica Acta
ER -