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A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature
The neuronal ceroid lipofuscinoses (NCLs), also known as Batten disease, are a group of autosomal recessive lysosomal storage disorders that are characterized by neurodegeneration, progressive cognitive decline, motor impairment, ataxia, loss of vision, seizures, and premature death. To date, pathog...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8640139/ https://www.ncbi.nlm.nih.gov/pubmed/34868216 http://dx.doi.org/10.3389/fgene.2021.746101 |
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author | Nicolaou, Paschalis Tanteles, George A. Votsi, Christina Zamba-Papanicolaou, Eleni Papacostas, Savvas S. Christodoulou, Kyproula Christou, Yiolanda-Panayiota |
author_facet | Nicolaou, Paschalis Tanteles, George A. Votsi, Christina Zamba-Papanicolaou, Eleni Papacostas, Savvas S. Christodoulou, Kyproula Christou, Yiolanda-Panayiota |
author_sort | Nicolaou, Paschalis |
collection | PubMed |
description | The neuronal ceroid lipofuscinoses (NCLs), also known as Batten disease, are a group of autosomal recessive lysosomal storage disorders that are characterized by neurodegeneration, progressive cognitive decline, motor impairment, ataxia, loss of vision, seizures, and premature death. To date, pathogenic variants in more than 13 genes have been associated with NCLs. CLN6 encodes an endoplasmic reticulum non-glycosylated transmembrane protein, which is involved in lysosomal acidification. Mutations in CLN6 cause late-infantile juvenile NCL (JNCL) adult-onset NCL, and Kufs disease. Members from two available families with JNCL were clinically evaluated, and samples were collected from consenting individuals. The molecular investigation was performed by whole-exome sequencing, Sanger sequencing, and family segregation analysis. Furthermore, in silico prediction analysis and structural modeling of the identified CLN6 variants were performed. We report clinical and genetic findings of three patients from two Greek-Cypriot families (families 915 and 926) with JNCL. All patients were males, and the first symptoms appeared at the age of 6 years. The proband of family 926 presented with loss of motor abilities, ataxia, spasticity, seizure, and epilepsy. The proband of family 915 had ataxia, spasticity, dysarthria, dystonia, and intellectual disability. Both probands did not show initial signs of vision and/or hearing loss. Molecular analysis of family 926 revealed two CLN6 biallelic variants: the novel, de novo p.Tyr295Cys and the known p.Arg136His variants. In family 915, both patients were homozygous for the p.Arg136His CLN6 variant. Prediction analysis of the two CLN6 variants characterized them as probably damaging and disease-causing. Structural modeling of the variants predicted that they probably cause protein structural differentiation. In conclusion, we describe two unrelated Cypriot families with JNCL. Both families had variants in the CLN6 gene; however, they presented with slightly different symptoms, and notably none of the patients has loss of vision. In silico prediction and structural analyses indicate that both variants are most likely pathogenic. |
format | Online Article Text |
id | pubmed-8640139 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-86401392021-12-04 A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature Nicolaou, Paschalis Tanteles, George A. Votsi, Christina Zamba-Papanicolaou, Eleni Papacostas, Savvas S. Christodoulou, Kyproula Christou, Yiolanda-Panayiota Front Genet Genetics The neuronal ceroid lipofuscinoses (NCLs), also known as Batten disease, are a group of autosomal recessive lysosomal storage disorders that are characterized by neurodegeneration, progressive cognitive decline, motor impairment, ataxia, loss of vision, seizures, and premature death. To date, pathogenic variants in more than 13 genes have been associated with NCLs. CLN6 encodes an endoplasmic reticulum non-glycosylated transmembrane protein, which is involved in lysosomal acidification. Mutations in CLN6 cause late-infantile juvenile NCL (JNCL) adult-onset NCL, and Kufs disease. Members from two available families with JNCL were clinically evaluated, and samples were collected from consenting individuals. The molecular investigation was performed by whole-exome sequencing, Sanger sequencing, and family segregation analysis. Furthermore, in silico prediction analysis and structural modeling of the identified CLN6 variants were performed. We report clinical and genetic findings of three patients from two Greek-Cypriot families (families 915 and 926) with JNCL. All patients were males, and the first symptoms appeared at the age of 6 years. The proband of family 926 presented with loss of motor abilities, ataxia, spasticity, seizure, and epilepsy. The proband of family 915 had ataxia, spasticity, dysarthria, dystonia, and intellectual disability. Both probands did not show initial signs of vision and/or hearing loss. Molecular analysis of family 926 revealed two CLN6 biallelic variants: the novel, de novo p.Tyr295Cys and the known p.Arg136His variants. In family 915, both patients were homozygous for the p.Arg136His CLN6 variant. Prediction analysis of the two CLN6 variants characterized them as probably damaging and disease-causing. Structural modeling of the variants predicted that they probably cause protein structural differentiation. In conclusion, we describe two unrelated Cypriot families with JNCL. Both families had variants in the CLN6 gene; however, they presented with slightly different symptoms, and notably none of the patients has loss of vision. In silico prediction and structural analyses indicate that both variants are most likely pathogenic. Frontiers Media S.A. 2021-11-19 /pmc/articles/PMC8640139/ /pubmed/34868216 http://dx.doi.org/10.3389/fgene.2021.746101 Text en Copyright © 2021 Nicolaou, Tanteles, Votsi, Zamba-Papanicolaou, Papacostas, Christodoulou and Christou. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Genetics Nicolaou, Paschalis Tanteles, George A. Votsi, Christina Zamba-Papanicolaou, Eleni Papacostas, Savvas S. Christodoulou, Kyproula Christou, Yiolanda-Panayiota A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature |
title | A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature |
title_full | A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature |
title_fullStr | A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature |
title_full_unstemmed | A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature |
title_short | A Novel CLN6 Variant Associated With Juvenile Neuronal Ceroid Lipofuscinosis in Patients With Absence of Visual Loss as a Presenting Feature |
title_sort | novel cln6 variant associated with juvenile neuronal ceroid lipofuscinosis in patients with absence of visual loss as a presenting feature |
topic | Genetics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8640139/ https://www.ncbi.nlm.nih.gov/pubmed/34868216 http://dx.doi.org/10.3389/fgene.2021.746101 |
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