Browsing by Author "Maver, Aleš (22135394900)"

Parkinson’s disease (PD) guidelines lack clear criteria for genetic evaluation. We assessed the yield and rationale of genetic testing for PD in a routine clinical setting on a multicenter cohort of 149 early-onset and familial patients by exome sequencing and semi-quantitative multiplex ligation-dependent probe amplification of evidence-based PD-associated gene panel. We show that genetic testing for PD should be considered for both early-onset and familial patients alike, and a clinical yield of about 10% in the Caucasian population can be expected. © 2022, The Author(s).

Parkinson’s disease (PD) guidelines lack clear criteria for genetic evaluation. We assessed the yield and rationale of genetic testing for PD in a routine clinical setting on a multicenter cohort of 149 early-onset and familial patients by exome sequencing and semi-quantitative multiplex ligation-dependent probe amplification of evidence-based PD-associated gene panel. We show that genetic testing for PD should be considered for both early-onset and familial patients alike, and a clinical yield of about 10% in the Caucasian population can be expected. © 2022, The Author(s).

The ABC and ACMG variant classification systems were compared by asking mainly European clinical laboratories to classify variants in 10 challenging cases using both systems, and to state if the variant in question would be reported as a relevant result or not as a measure of clinical utility. In contrast to the ABC system, the ACMG system was not made to guide variant reporting but to determine the likelihood of pathogenicity. Nevertheless, this comparison is justified since the ACMG class determines variant reporting in many laboratories. Forty-three laboratories participated in the survey. In seven cases, the classification system used did not influence the reporting likelihood when variants labeled as “maybe report” after ACMG-based classification were included. In three cases of population frequent but disease-associated variants, there was a difference in favor of reporting after ABC classification. A possible reason is that ABC step C (standard variant comments) allows a variant to be reported in one clinical setting but not another, e.g., based on Bayesian-based likelihood calculation of clinical relevance. Finally, the selection of ACMG criteria was compared between 36 laboratories. When excluding criteria used by less than four laboratories (<10%), the average concordance rate was 46%. Taken together, ABC-based classification is more clear-cut than ACMG-based classification since molecular and clinical information is handled separately, and variant reporting can be adapted to the clinical question and phenotype. Furthermore, variants do not get a clinically inappropriate label, like pathogenic when not pathogenic in a clinical context, or variant of unknown significance when the significance is known. © The Author(s) 2024.

The ABC and ACMG variant classification systems were compared by asking mainly European clinical laboratories to classify variants in 10 challenging cases using both systems, and to state if the variant in question would be reported as a relevant result or not as a measure of clinical utility. In contrast to the ABC system, the ACMG system was not made to guide variant reporting but to determine the likelihood of pathogenicity. Nevertheless, this comparison is justified since the ACMG class determines variant reporting in many laboratories. Forty-three laboratories participated in the survey. In seven cases, the classification system used did not influence the reporting likelihood when variants labeled as “maybe report” after ACMG-based classification were included. In three cases of population frequent but disease-associated variants, there was a difference in favor of reporting after ABC classification. A possible reason is that ABC step C (standard variant comments) allows a variant to be reported in one clinical setting but not another, e.g., based on Bayesian-based likelihood calculation of clinical relevance. Finally, the selection of ACMG criteria was compared between 36 laboratories. When excluding criteria used by less than four laboratories (<10%), the average concordance rate was 46%. Taken together, ABC-based classification is more clear-cut than ACMG-based classification since molecular and clinical information is handled separately, and variant reporting can be adapted to the clinical question and phenotype. Furthermore, variants do not get a clinically inappropriate label, like pathogenic when not pathogenic in a clinical context, or variant of unknown significance when the significance is known. © The Author(s) 2024.

Study question: Are de novo mutations in the human genome associated with male infertility?. Summary answer: We identified de novo mutations in five candidate genes: SEMA5A, NEURL4, BRD2, CD1D, and CD63. What is known already: Epidemiological and genetic studies have consistently indicated contribution of genetic factors to the etiology of male infertility, suggesting that more than 1500 genes are involved in spermatogenesis. Study design, size, duration: First, we searched for de novo mutations in patients with idiopathic azoospermia with whole-exome sequencing (WES). To evaluate the potential functional impact of de novo identified mutations, we analyzed their expression differences on independent testis samples with normal and impaired spermatogenesis. In the next step, we tested additional group of azoospermic patients for mutations in identified genes with de novo mutations. In addition to the analysis of de novo mutations in patients with idiopathic azoospermia, we considered other models of inheritance and searched for candidate genes harboring rare maternally inherited variants and biallelic autosomal and X-chromosome hemizygous variants. Participants/materials, setting, methods: We performed WES in 13 infertile males with idiopathic azoospermia and their parents. Potential functional impact of de novo identified mutations was evaluated by global gene expression profiling on 20 independent testis samples. To replicate the results, we performed WES in further 16 independent azoospermic males, which were screened for the variants in the same genes. Library preparation was performed with Nextera Coding Exome Capture Kit (Illumina), with subsequent sequencing on Illumina HiSeq 2500 platform. Main results and the role of chance: We identified 11 de novo mutations in 10 genes of which 5 were considered potentially associated with azoospermia: SEMA5A, NEURL4, BRD2, CD1D, and CD63. All candidate genes showed significant differential expression in testis samples composed of patients with severely impaired and normal spermatogenesis. Additionally, we identified rare, potentially pathogenic mutations in the genes previously implicated in male infertility—a maternally inherited heterozygous frameshift variant in FKBPL gene and inframe deletion in UPF2 gene, homozygous frameshift variant in CLCA4 gene, and a heterozygous missense variant NR0B1 gene, which represent promising candidates for further clinical implication. Limitations of the study, reasons for caution: We provided limited functional support for involvement of de novo identified genes in pathogenesis of male infertility, based on expression analysis. Additionally, the sample size was limited. Wider implications of the findings: We provide support that de novo mutations might contribute to male infertility and propose five genes as potentially implicated in its pathogenesis. © 2020 American Society of Andrology and European Academy of Andrology

Study question: Are de novo mutations in the human genome associated with male infertility?. Summary answer: We identified de novo mutations in five candidate genes: SEMA5A, NEURL4, BRD2, CD1D, and CD63. What is known already: Epidemiological and genetic studies have consistently indicated contribution of genetic factors to the etiology of male infertility, suggesting that more than 1500 genes are involved in spermatogenesis. Study design, size, duration: First, we searched for de novo mutations in patients with idiopathic azoospermia with whole-exome sequencing (WES). To evaluate the potential functional impact of de novo identified mutations, we analyzed their expression differences on independent testis samples with normal and impaired spermatogenesis. In the next step, we tested additional group of azoospermic patients for mutations in identified genes with de novo mutations. In addition to the analysis of de novo mutations in patients with idiopathic azoospermia, we considered other models of inheritance and searched for candidate genes harboring rare maternally inherited variants and biallelic autosomal and X-chromosome hemizygous variants. Participants/materials, setting, methods: We performed WES in 13 infertile males with idiopathic azoospermia and their parents. Potential functional impact of de novo identified mutations was evaluated by global gene expression profiling on 20 independent testis samples. To replicate the results, we performed WES in further 16 independent azoospermic males, which were screened for the variants in the same genes. Library preparation was performed with Nextera Coding Exome Capture Kit (Illumina), with subsequent sequencing on Illumina HiSeq 2500 platform. Main results and the role of chance: We identified 11 de novo mutations in 10 genes of which 5 were considered potentially associated with azoospermia: SEMA5A, NEURL4, BRD2, CD1D, and CD63. All candidate genes showed significant differential expression in testis samples composed of patients with severely impaired and normal spermatogenesis. Additionally, we identified rare, potentially pathogenic mutations in the genes previously implicated in male infertility—a maternally inherited heterozygous frameshift variant in FKBPL gene and inframe deletion in UPF2 gene, homozygous frameshift variant in CLCA4 gene, and a heterozygous missense variant NR0B1 gene, which represent promising candidates for further clinical implication. Limitations of the study, reasons for caution: We provided limited functional support for involvement of de novo identified genes in pathogenesis of male infertility, based on expression analysis. Additionally, the sample size was limited. Wider implications of the findings: We provide support that de novo mutations might contribute to male infertility and propose five genes as potentially implicated in its pathogenesis. © 2020 American Society of Andrology and European Academy of Andrology

Primary microcephalies (MCPH) are characterized by microcephaly (HC -2 SD at birth) in the absence of visceral malformations. To date, less than 20 genes have been associated with MCHP, several of which are involved in the formation and function of the centrosome. Here, we report a novel missense variant in the TUBGCP5 gene in a patient with primary microcephaly and mild developmental delay. The TUBCGP5 gene (tubulin gamma complex associated protein 5) is a paralog of TUBGCP4 and TUBGCP6, both of which are known MCPH associated genes, and like its’ paralogs, is involved in centrosome formation. Furthermore, the TUBGCP5 gene is located in the 15q11.2 BP1-BP2 microdeletion Burnside-Butler susceptibility locus that is part of the larger Prader-Willi/Angelman region. Common clinical features of the 15q11.2 BP1-BP2 microdeletion include general developmental and neurodevelopmental delay which may occasionally be accompanied by yet unexplained microcephaly. In our patient, the TUBGCP5:c.2180T > G, p.Phe727Cys missense variant was identified in compound heterozygous state with 15q11.2 BP1-BP2 microdeletion using whole exome sequencing, after the initial analyses of known MCPH genes failed to identify a conclusively causative variant. The identified variant is rare and highly conserved, as shown by population allele frequency data from ExAC and GnomAD, as well as comparisons with all other vertebrates. Based on this evidence we suggest that the identified TUBGCP5 variant in our patient may thus represent a novel cause of MCPH with mild developmental delay and may play a role in occurrence of microcephaly in 15q11.2 microdeletion carriers. Further studies are required to further clarify the causality and penetrance of TBGCP5 variants in primary microcephaly. © 2018 Elsevier Masson SAS

Primary microcephalies (MCPH) are characterized by microcephaly (HC -2 SD at birth) in the absence of visceral malformations. To date, less than 20 genes have been associated with MCHP, several of which are involved in the formation and function of the centrosome. Here, we report a novel missense variant in the TUBGCP5 gene in a patient with primary microcephaly and mild developmental delay. The TUBCGP5 gene (tubulin gamma complex associated protein 5) is a paralog of TUBGCP4 and TUBGCP6, both of which are known MCPH associated genes, and like its’ paralogs, is involved in centrosome formation. Furthermore, the TUBGCP5 gene is located in the 15q11.2 BP1-BP2 microdeletion Burnside-Butler susceptibility locus that is part of the larger Prader-Willi/Angelman region. Common clinical features of the 15q11.2 BP1-BP2 microdeletion include general developmental and neurodevelopmental delay which may occasionally be accompanied by yet unexplained microcephaly. In our patient, the TUBGCP5:c.2180T > G, p.Phe727Cys missense variant was identified in compound heterozygous state with 15q11.2 BP1-BP2 microdeletion using whole exome sequencing, after the initial analyses of known MCPH genes failed to identify a conclusively causative variant. The identified variant is rare and highly conserved, as shown by population allele frequency data from ExAC and GnomAD, as well as comparisons with all other vertebrates. Based on this evidence we suggest that the identified TUBGCP5 variant in our patient may thus represent a novel cause of MCPH with mild developmental delay and may play a role in occurrence of microcephaly in 15q11.2 microdeletion carriers. Further studies are required to further clarify the causality and penetrance of TBGCP5 variants in primary microcephaly. © 2018 Elsevier Masson SAS