Activity

Filter

Cancel
Date Panel Item Activity
9 actions
Paediatric or syndromic cardiomyopathy v3.43 PLD1 Jesse Hayesmoore changed review comment from: On the basis of functional data described in PMIDs: 27799408 and 33645542, PLD1 certainly seems to be a plausible functional candidate for causality of cardiac valvular defects. The main paper linking this gene with congenital heart disease / cardiomyopathy is Lahrouchi et al. (2021; PMID: 33645542; note this also includes the same 2 cases as described in Ta-Shma et al. 2017 PMID: 27799408). The paper presents 19 families with severe fetal- / neonatal-onset congenital heart (mainly valvular) defects and 2 with cardiomyopathy where affected babies were homozygous or compound heterozygous for PLD1 variants. The paper also provides some functional analysis of missense variants detected, showing that many but not all of them result significant loss of PLD1 function. Unfortunately, the paper does not include a LOD score, and there is very little cosegregation data presented for any of the variants. In addition, 4 of the 31 variants they promote as pathogenic for autosomal recessive disease are detected in multiple homozygous individuals on gnomAD, which I think provides significant evidence that they might not be pathogenic for a severe autosomal recessive condition. Most notably, 1 of the variants (i.e. I668F), which the authors promote as a pathogenic Ashkenazi Jewish founder variant (but which is also fairly frequent in non-Finnish Europeans) is detected in 7 homozygotes on gnomAD and was found to have ~80% loss of PLD1 function in their assay. This suggests that significant loss of function of this gene (i.e. down to 20%) might not be causative of a severe recessive condition (that is not to say that total or near total loss of function is not causative). Three other of the variants promoted as pathogenic in this article are also detected in homozygotes on gnomAD.

I think one of the major pieces of missing information required to make a full assessment of this gene’s linkage to disease is that is unknown how frequent biallelic (apparently loss of function) variant genotypes are in the general population or in healthy control individuals. Although homozygosity for any one variant can be determined from gnomAD, compound heterozygosity (which is likely to represent the vast majority of biallelic genotypes) cannot be assessed on gnomAD, and I can find no record in the literature of this being assessed in a normal control cohort. Without this information, we cannot know whether biallelic PLD1 genotypes are specific to babies with this severe phenotype. Without knowing this, and in the absence of any significant cosegregation data for any variant, there is no reasonable basis upon which one can conclude that this is a valid autosomal recessive gene for the phenotype. Without such validation, PVS1 cannot be applied for any apparent loss of function variant. Given this, and the general lack of cosegregation data for any one variant, I do not believe there is any PLD1 variant reported in the literature that could be classified as anything but uncertain significance (if not benign or likely benign) on the basis of current variant classification guidelines. Also, there are only two cases of biallelic variants in neonates where the primary phenotype is cardiomyopathy, and of these only one was dilated cardiomyopathy (the other was histiocytoid cardiomyopathy). Hence, the evidence linking this gene to cardiomyopathy is even weaker than it is for valvular defects. I, therefore, do not feel there is sufficient evidence to justify this gene being tested as part of the R135 paediatric cardiomyopathy gene panel.

Other papers (e.g. PMIDs: 33142350, 35380090, 36923242, 37770978) reporting a link between PLD1 genotypes and early onset cardiac disease have been published. However, again, I do not think there is sufficient data in the articles to allow any of the variants detected to be confidently classified as anything but VUS according to current variant classification guidelines. ; to: On the basis of functional data described in PMIDs: 27799408 and 33645542, PLD1 certainly seems to be a plausible functional candidate for causality of cardiac valvular defects. The main paper linking this gene with congenital heart disease / cardiomyopathy is Lahrouchi et al. (2021; PMID: 33645542; note this also includes the same 2 cases as described in Ta-Shma et al. 2017 PMID: 27799408). The paper presents 19 families with severe fetal- / neonatal-onset congenital heart (mainly valvular) defects and 2 with cardiomyopathy where affected babies were homozygous or compound heterozygous for PLD1 variants. The paper also provides some functional analysis of missense variants detected, showing that many but not all of them result significant loss of PLD1 function. Unfortunately, the paper does not include a LOD score, and there is very little cosegregation data presented for any of the variants. In addition, 4 of the 31 variants they promote as pathogenic for autosomal recessive disease are detected in multiple homozygous individuals on gnomAD, which I think provides significant evidence that they might not be pathogenic for a severe autosomal recessive condition. Most notably, 1 of the variants (i.e. I668F), which the authors promote as a pathogenic Ashkenazi Jewish founder variant (but which is also fairly frequent in non-Finnish Europeans) is detected in 7 homozygotes on gnomAD and was found to have ~80% loss of PLD1 function in their assay. This suggests that significant loss of function of this gene (i.e. down to 20%) might not be causative of a severe recessive condition (that is not to say that total or near total loss of function is not causative). Three other of the variants promoted as pathogenic in this article are also detected in homozygotes on gnomAD.

I think one of the major pieces of missing information required to make a full assessment of this gene’s linkage to disease is that is unknown how frequent biallelic (apparently loss of function) variant genotypes are in the general population or in healthy control individuals. Although homozygosity for any one variant can be determined from gnomAD, compound heterozygosity (which is likely to represent the vast majority of biallelic genotypes) cannot be assessed on gnomAD, and I can find no record in the literature of this being assessed in a normal control cohort. Without this information, we cannot know whether biallelic PLD1 genotypes are specific to babies with this severe phenotype. Without knowing this, and in the absence of any significant cosegregation data for any variant, there is no reasonable basis upon which one can conclude that this is a valid autosomal recessive gene for the phenotype. Without such validation, PVS1 cannot be applied for any apparent loss of function variant. Given this, and the general lack of cosegregation data for any one variant, I do not believe there is any PLD1 variant reported in the literature that could be classified as anything but uncertain significance (if not benign or likely benign) on the basis of current variant classification guidelines. Also, there are only two cases of biallelic variants in neonates where the primary phenotype is cardiomyopathy, and of these only one was dilated cardiomyopathy (the other was histiocytoid cardiomyopathy). Hence, the evidence linking this gene to cardiomyopathy is even weaker than it is for valvular defects. I, therefore, do not feel there is sufficient evidence to justify this gene being tested as part of the R135 paediatric cardiomyopathy gene panel.

Other papers (e.g. PMIDs: 33142350, 35380090, 36923242, 37770978) reporting a link between PLD1 genotypes and early onset cardiac disease (not cardiomyopathy) have been published. However, again, I do not think there is sufficient data in the articles to allow any of the variants detected to be confidently classified as anything but VUS according to current variant classification guidelines.
Paediatric or syndromic cardiomyopathy v3.43 PLD1 Jesse Hayesmoore changed review comment from: On the basis of functional data described in PMIDs: 27799408 and 33645542, PLD1 certainly seems to be a plausible functional candidate for causality of cardiac valvular defects. The main paper linking this gene with congenital heart disease / cardiomyopathy is Lahrouchi et al. (2021; PMID: 33645542; note this also includes the same 2 cases as described in Ta-Shma et al. 2017 PMID: 27799408). The paper presents 19 families with severe fetal- / neonatal-onset congenital heart (mainly valvular) defects and 2 with cardiomyopathy where affected babies were homozygous or compound heterozygous for PLD1 variants. The paper also provides some functional analysis of missense variants detected, showing that many but not all of them result significant loss of PLD1 function. Unfortunately, the paper does not include a LOD score, and there is very little cosegregation data presented for any of the variants. In addition, 4 of the 31 variants they promote as pathogenic for autosomal recessive disease are detected in multiple homozygous individuals on gnomAD, which I think provides significant evidence that they might not be pathogenic for a severe autosomal recessive condition. Most notably, 1 of the variants (i.e. I668F), which the authors promote as a pathogenic Ashkenazi Jewish founder variant (but which is also fairly frequent in non-Finnish Europeans) is detected in 7 homozygotes on gnomAD and was found to have ~80% loss of PLD1 function in their assay. This suggests that significant loss of function of this gene (i.e. down to 20%) might not be causative of a severe recessive condition (that is not to say that total or near total loss of function is not causative). Three other of the variants promoted as pathogenic in this article are also detected in homozygotes on gnomAD.

I think one of the major pieces of missing information required to make a full assessment of this gene’s linkage to disease is that is unknown how frequent biallelic (apparently loss of function) variant genotypes are in the general population or in healthy control individuals. Although homozygosity for any one variant can be determined from gnomAD, compound heterozygosity (which is likely to represent the vast majority of biallelic genotypes) cannot be assessed on gnomAD, and I can find no record in the literature of this being assessed in a normal control cohort. Without this information, we cannot know whether biallelic PLD1 genotypes are specific to babies with this severe phenotype. Without knowing this, and in the absence of any significant cosegregation data for any variant, there is no reasonable basis upon which one can conclude that this is a valid autosomal recessive gene for the phenotype. Without such validation, PVS1 cannot be applied for any apparent loss of function variant. Given this, and the general lack of cosegregation data for any one variant, I do not believe there is any PLD1 variant reported in the literature that could be classified as anything but uncertain significance (if not benign or likely benign). Also, there are only two cases of biallelic variants in neonates where the primary phenotype is cardiomyopathy, and of these only one was dilated cardiomyopathy (the other was histiocytoid cardiomyopathy). Hence, the evidence linking this gene to cardiomyopathy is even weaker than it is for valvular defects. I, therefore, do not feel there is sufficient evidence to justify this gene being tested as part of the R135 paediatric cardiomyopathy gene panel.; to: On the basis of functional data described in PMIDs: 27799408 and 33645542, PLD1 certainly seems to be a plausible functional candidate for causality of cardiac valvular defects. The main paper linking this gene with congenital heart disease / cardiomyopathy is Lahrouchi et al. (2021; PMID: 33645542; note this also includes the same 2 cases as described in Ta-Shma et al. 2017 PMID: 27799408). The paper presents 19 families with severe fetal- / neonatal-onset congenital heart (mainly valvular) defects and 2 with cardiomyopathy where affected babies were homozygous or compound heterozygous for PLD1 variants. The paper also provides some functional analysis of missense variants detected, showing that many but not all of them result significant loss of PLD1 function. Unfortunately, the paper does not include a LOD score, and there is very little cosegregation data presented for any of the variants. In addition, 4 of the 31 variants they promote as pathogenic for autosomal recessive disease are detected in multiple homozygous individuals on gnomAD, which I think provides significant evidence that they might not be pathogenic for a severe autosomal recessive condition. Most notably, 1 of the variants (i.e. I668F), which the authors promote as a pathogenic Ashkenazi Jewish founder variant (but which is also fairly frequent in non-Finnish Europeans) is detected in 7 homozygotes on gnomAD and was found to have ~80% loss of PLD1 function in their assay. This suggests that significant loss of function of this gene (i.e. down to 20%) might not be causative of a severe recessive condition (that is not to say that total or near total loss of function is not causative). Three other of the variants promoted as pathogenic in this article are also detected in homozygotes on gnomAD.

I think one of the major pieces of missing information required to make a full assessment of this gene’s linkage to disease is that is unknown how frequent biallelic (apparently loss of function) variant genotypes are in the general population or in healthy control individuals. Although homozygosity for any one variant can be determined from gnomAD, compound heterozygosity (which is likely to represent the vast majority of biallelic genotypes) cannot be assessed on gnomAD, and I can find no record in the literature of this being assessed in a normal control cohort. Without this information, we cannot know whether biallelic PLD1 genotypes are specific to babies with this severe phenotype. Without knowing this, and in the absence of any significant cosegregation data for any variant, there is no reasonable basis upon which one can conclude that this is a valid autosomal recessive gene for the phenotype. Without such validation, PVS1 cannot be applied for any apparent loss of function variant. Given this, and the general lack of cosegregation data for any one variant, I do not believe there is any PLD1 variant reported in the literature that could be classified as anything but uncertain significance (if not benign or likely benign) on the basis of current variant classification guidelines. Also, there are only two cases of biallelic variants in neonates where the primary phenotype is cardiomyopathy, and of these only one was dilated cardiomyopathy (the other was histiocytoid cardiomyopathy). Hence, the evidence linking this gene to cardiomyopathy is even weaker than it is for valvular defects. I, therefore, do not feel there is sufficient evidence to justify this gene being tested as part of the R135 paediatric cardiomyopathy gene panel.

Other papers (e.g. PMIDs: 33142350, 35380090, 36923242, 37770978) reporting a link between PLD1 genotypes and early onset cardiac disease have been published. However, again, I do not think there is sufficient data in the articles to allow any of the variants detected to be confidently classified as anything but VUS according to current variant classification guidelines.
Paediatric or syndromic cardiomyopathy v3.43 PLD1 Jesse Hayesmoore reviewed gene: PLD1: Rating: RED; Mode of pathogenicity: Other; Publications: PMIDs: 27799408 and 33645542; Phenotypes: Paediatric cardiomyopathy, cardiac valvular defects; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal; Current diagnostic: yes
Paediatric or syndromic cardiomyopathy v1.67 IDS Ivone Leong commented on gene: IDS: The rating of this gene has been updated following NHS Genomic Medicine Service approval.
Paediatric or syndromic cardiomyopathy v1.66 IDS Ivone Leong Source Expert Review Amber was added to IDS.
Rating Changed from Green List (high evidence) to Amber List (moderate evidence)
Paediatric or syndromic cardiomyopathy v0.16 IDS Ivone Leong reviewed gene: IDS: Rating: GREEN; Mode of pathogenicity: ; Publications: ; Phenotypes: ; Mode of inheritance:
Paediatric or syndromic cardiomyopathy v0.15 IDS Ivone Leong Source NHS GMS was added to IDS.
Paediatric or syndromic cardiomyopathy v0.1 TAZ Ivone Leong gene: TAZ was added
gene: TAZ was added to Cardiomyopathies - including childhood onset. Sources: Expert Review Green,MetBioNet,London South GLH,South West GLH
Mode of inheritance for gene: TAZ was set to BOTH monoallelic and biallelic (but BIALLELIC mutations cause a more SEVERE disease form), autosomal or pseudoautosomal
Publications for gene: TAZ were set to 27604308
Phenotypes for gene: TAZ were set to Disorders of mitochondrial lipid metabolism; Dilated Cardiomyopathy, X-Linked; Neutropenia, muscle weakness, growth retardation; Non-compaction cardiomyopathy; Barth syndrome, 302060; Left Ventricular Noncompaction Cardiomyopathy; HCM, mixed; Disorders of mitochondrial membrane lipids (Mitochondrial respiratory chain disorders (caused by nuclear variants only)); Barth syndrome; Methylglutaconic aciduria type II, Barth syndrome (Organic acidurias)
Paediatric or syndromic cardiomyopathy v0.1 IDS Ivone Leong gene: IDS was added
gene: IDS was added to Cardiomyopathies - including childhood onset. Sources: Expert Review Green,MetBioNet
Mode of inheritance for gene: IDS was set to X-LINKED: hemizygous mutation in males, biallelic mutations in females
Publications for gene: IDS were set to 27604308
Phenotypes for gene: IDS were set to MPS II, Hunter disease (Mucopolysaccharidoses); MUCOPOLYSACCHARIDOSIS TYPE 2; Mucopolysaccharidosis II, 309900; Mucopolysaccharidosis Type II