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Fetal anomalies v3.156 PLD1 Arina Puzriakova commented on gene: PLD1: Copied review from Paediatric or syndromic cardiomyopathy (749) v3.43 panel:

Jesse Hayesmoore (Oxford Regional Genetics Laboratory)
Red List (low evidence)

"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."
Created: 31 Jan 2024, 12:04 p.m. | Last Modified: 31 Jan 2024, 12:17 p.m
Fetal anomalies v1.59 SUZ12 Eleanor Williams Phenotypes for gene: SUZ12 were changed from Weaver-like overgrowth syndrome to Weaver-like overgrowth syndrome; Imagawa-Matsumoto syndrome #618786
Fetal anomalies v0.225 CTDP1 Rebecca Foulger edited their review of gene: CTDP1: Added comment: This gene and phenotype were reviewed during meetings at Great Ormond Street hospital in March and April 2019. Clinical review and curation was performed by Lyn Chitty, Anna de Burca, Rhiannon Mellis, Richard Scott, Ellen McDonagh and Rebecca Foulger. Outcome of review: Phenotype is fetally-relevant but limited evidence: include on the Fetal anomalies panel as an Amber gene. Additional notes from clinical review: Although CTDP1 has a 'confirmed' Disease confidence rating in DD-G2P for CONGENITAL CATARACTS FACIAL DYSMORPHISM AND NEUROPATHY SYNDROME, the disorder is prevalent in Bulagarian Gypsy populations, and is limited to a founder variant.; Changed publications: 14517542, 29174527, 20301787, 24690360
Fetal anomalies v0.225 SUZ12 Rebecca Foulger edited their review of gene: SUZ12: Added comment: This gene and phenotype were reviewed during meetings at Great Ormond Street hospital in March and April 2019. Clinical review and curation was performed by Lyn Chitty, Anna de Burca, Rhiannon Mellis, Richard Scott, Ellen McDonagh and Rebecca Foulger. Outcome of review: Confirmed that phenotype is fetally-relevant: include on the Fetal anomalies panel as a Green gene. Additional notes from clinical review: Fetal relevance is borderline- PMIDs:28229514 and 30019515 report a set of features where it is unclear if they would be detected prenatally, including one case of increased head circumference at birth (but also one case with reduced head circumference at birth) some facial and limb features etc. Evidence wise, there are just enough cases from the literature (2 papers from the same group) to support inclusion: Imagawa et al., 2017 (PMID:28229514) identified a missense somatic mosaic mutation (c.1829A>T, p.Glu610Val) in SUZ12 in a patient with clinically suspected Weaver syndrome. Imagawa et al., 2018 (PMID:30019515) report two further Weaver syndrome-like patients with SUZ12 variants (a missense and a frameshift). On balance, it was decided that SUZ12 should be included on the Fetal anomalies panel.; Changed rating: GREEN; Changed publications: 28229514, 30019515
Fetal anomalies v0.135 AGA Rebecca Foulger Source Expert Review Red was added to AGA.
Rating Changed from Green List (high evidence) to Red List (low evidence)
Fetal anomalies v0.134 NAGA Rebecca Foulger edited their review of gene: NAGA: Added comment: This gene and phenotype were reviewed during meetings at Great Ormond Street hospital in March 2019. Clinical review and curation was performed by Lyn Chitty, Anna de Burca, Rhiannon Mellis, Richard Scott, Ellen McDonagh and Rebecca Foulger. Outcome of review: Confirmed that phenotype is fetally-relevant: keep on the Fetal anomalies panel as a Green gene.; Changed rating: GREEN
Fetal anomalies v0.134 AGA Rebecca Foulger edited their review of gene: AGA: Added comment: This gene and phenotype were reviewed during meetings at Great Ormond Street hospital in March 2019. Clinical review and curation was performed by Lyn Chitty, Anna de Burca, Rhiannon Mellis, Richard Scott, Ellen McDonagh and Rebecca Foulger. Outcome of review: Phenotype is not fetally-relevant. Action taken: Demoted AGA gene rating from Green to Red.; Changed rating: RED
Fetal anomalies v0.9 PIK3R1 Rebecca Foulger commented on gene: PIK3R1: DDG2P rating in original PAGE list: Confirmed for SHORT SYNDROME and Confirmed for AGAMMAGLOBULINEMIA 7, AUTOSOMAL RECESSIVE.
Fetal anomalies v0.9 NAGA Rebecca Foulger reviewed gene: NAGA: Rating: AMBER; Mode of pathogenicity: ; Publications: ; Phenotypes: ; Mode of inheritance:
Fetal anomalies v0.9 AGA Rebecca Foulger reviewed gene: AGA: Rating: AMBER; Mode of pathogenicity: ; Publications: ; Phenotypes: ; Mode of inheritance:
Fetal anomalies v0.1 PIK3R1 Rebecca Foulger Added phenotypes AGAMMAGLOBULINEMIA 7, AUTOSOMAL RECESSIVE for gene: PIK3R1
Fetal anomalies v0.1 NAGA Rebecca Foulger Added phenotypes SCHINDLER DISEASE for gene: NAGA
Fetal anomalies v0.1 NAGA Rebecca Foulger gene: NAGA was added
gene: NAGA was added to Fetal anomalies. Sources: Expert Review Green,PAGE DD-Gene2Phenotype
Mode of inheritance for gene: NAGA was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: NAGA were set to KANZAKI DISEASE
Fetal anomalies v0.1 AGA Rebecca Foulger gene: AGA was added
gene: AGA was added to Fetal anomalies. Sources: Expert Review Green,PAGE DD-Gene2Phenotype
Mode of inheritance for gene: AGA was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: AGA were set to ASPARTYLGLUCOSAMINURIA