rs56851164

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_170707.4(LMNA):​c.976T>A​(p.Ser326Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000849 in 1,613,696 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S326L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000086 ( 0 hom. )

Consequence

LMNA
NM_170707.4 missense

Scores

5
15

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:11B:1O:1

Conservation

PhyloP100: 0.876
Variant links:
Genes affected
LMNA (HGNC:6636): (lamin A/C) The protein encoded by this gene is part of the nuclear lamina, a two-dimensional matrix of proteins located next to the inner nuclear membrane. The lamin family of proteins make up the matrix and are highly conserved in evolution. During mitosis, the lamina matrix is reversibly disassembled as the lamin proteins are phosphorylated. Lamin proteins are thought to be involved in nuclear stability, chromatin structure and gene expression. Vertebrate lamins consist of two types, A and B. Alternative splicing results in multiple transcript variants. Mutations in this gene lead to several diseases: Emery-Dreifuss muscular dystrophy, familial partial lipodystrophy, limb girdle muscular dystrophy, dilated cardiomyopathy, Charcot-Marie-Tooth disease, and Hutchinson-Gilford progeria syndrome. [provided by RefSeq, May 2022]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_170707.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), LMNA. . Gene score misZ 2.3673 (greater than the threshold 3.09). Trascript score misZ 3.0905 (greater than threshold 3.09). GenCC has associacion of gene with familial partial lipodystrophy, Dunnigan type, autosomal recessive Emery-Dreifuss muscular dystrophy, LMNA-related cardiocutaneous progeria syndrome, atrioventricular block, dilated cardiomyopathy 1A, Emery-Dreifuss muscular dystrophy 2, autosomal dominant, atypical Werner syndrome, restrictive dermopathy 1, autosomal semi-dominant severe lipodystrophic laminopathy, Emery-Dreifuss muscular dystrophy 3, autosomal recessive, dilated cardiomyopathy, Charcot-Marie-Tooth disease type 2B1, dilated cardiomyopathy-hypergonadotropic hypogonadism syndrome, arrhythmogenic right ventricular cardiomyopathy, familial isolated dilated cardiomyopathy, mandibuloacral dysplasia with type A lipodystrophy, autosomal dominant Emery-Dreifuss muscular dystrophy, heart-hand syndrome, Slovenian type, congenital muscular dystrophy due to LMNA mutation, lethal restrictive dermopathy, Hutchinson-Gilford progeria syndrome.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
LMNANM_170707.4 linkuse as main transcriptc.976T>A p.Ser326Thr missense_variant 6/12 ENST00000368300.9
LMNANM_005572.4 linkuse as main transcriptc.976T>A p.Ser326Thr missense_variant 6/10 ENST00000677389.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
LMNAENST00000368300.9 linkuse as main transcriptc.976T>A p.Ser326Thr missense_variant 6/121 NM_170707.4 P1P02545-1
LMNAENST00000677389.1 linkuse as main transcriptc.976T>A p.Ser326Thr missense_variant 6/10 NM_005572.4 P02545-2

Frequencies

GnomAD3 genomes
AF:
0.0000789
AC:
12
AN:
152092
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000725
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000132
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000560
AC:
14
AN:
249958
Hom.:
0
AF XY:
0.0000443
AC XY:
6
AN XY:
135434
show subpopulations
Gnomad AFR exome
AF:
0.0000629
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000115
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000855
AC:
125
AN:
1461604
Hom.:
0
Cov.:
34
AF XY:
0.0000811
AC XY:
59
AN XY:
727126
show subpopulations
Gnomad4 AFR exome
AF:
0.0000597
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000106
Gnomad4 OTH exome
AF:
0.0000828
GnomAD4 genome
AF:
0.0000789
AC:
12
AN:
152092
Hom.:
0
Cov.:
32
AF XY:
0.0000942
AC XY:
7
AN XY:
74304
show subpopulations
Gnomad4 AFR
AF:
0.0000725
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000132
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000565
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000577
AC:
7
EpiCase
AF:
0.000164
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:11Benign:1Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3Other:1
not provided, no classification providedliterature onlyEpithelial Biology; Institute of Medical Biology, Singapore-- -
Uncertain significance, criteria provided, single submitterclinical testingMayo Clinic Laboratories, Mayo ClinicJan 16, 2023- -
Uncertain significance, criteria provided, single submitterclinical testingGeneDxJun 01, 2023In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 22071332, 23142632, 16585054, 27532257, 16407522, 20627339, 28663758, 9536090, 22224630, 28518168, 31019283, 29095976, 29237690, 28679633, 24846508, 10939567, 34862408, 34240052, 36975868, 33673806, 31476771, 24503780) -
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Dec 08, 2015- -
not specified Uncertain:3
Uncertain significance, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJul 31, 2023Variant summary: LMNA c.976T>A (p.Ser326Thr) results in a conservative amino acid change located in the Intermediate filament, rod domain (IPR039008) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 5.6e-05 in 249958 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in LMNA causing Dilated Cardiomyopathy (5.6e-05 vs 0.0001), allowing no conclusion about variant significance. c.976T>A has been reported in the literature in individuals affected with Cardiomyopathy or muscle laminopathy without strong evidence of causality (e.g. Muntoni_2006, Pugh_2014, Walsh_2017, Ben Yaou_2021, Hathaway_2021, Park_2020). These reports do not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. At least one publication reports experimental evidence evaluating an impact on protein function, finding no effect of the variant on laminim A aggregation (Anderson_2021). The following publications have been ascertained in the context of this evaluation (PMID: 16585054, 23142632, 24503780, 27532257, 31019283, 34862408, 34240052, 33673806, 31383942, 25274841, 22071332). Nine submitters have cited clinical-significance assessments for this variant to ClinVar after 2014, and classified it as uncertain significance (n=7), likely pathogenic (n=1) or likely benign (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Uncertain significance, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesJul 03, 2018The LMNA c.976T>A; p.Ser326Thr variant (rs56851164), is reported in the literature in individuals affected with dilated cardiomyopathy and Emery-Dreifuss muscular dystrophy (Hasselberg 2018, Muntoni 2006, Pugh 2014), and is reported in ClinVar (Variation ID: 48097). In a family with X-linked Emery-Dreifuss muscular dystrophy segregating with a STA p.Tyr105Ter variant, a presumed de novo LMNA c.976T>A; p.Ser326Thr variant was identified in one affected individual presenting with much more severe clinical symptoms than two other affected family members. This variant occurs in the functionally important coil 2B domain that mediates lamin A/C oligomerization; however, molecular dynamics modeling of the LMNA c.976T>A; p.Ser326Thr variant suggested no effect on protein dimerization, although the authors concede other mechanisms could still account for pathogenicity (Gangemi 2013). This variant is found in the non-Finnish European population with an overall allele frequency of 0.012% (15/126146 alleles) in the Genome Aggregation Database, and a recent study classified this variant as likely benign due to its population frequency above a maximum allele frequency threshold (MAF < 0.01%) expected for pathogenic variants (Walsh 2017). The serine at codon 326 is weakly conserved, and computational analyses (SIFT, PolyPhen-2) predict that this variant is tolerated. Due to conflicting information, the clinical significance of the LMNA c.976T>A; p.Ser326Thr variant is uncertain at this time. -
Uncertain significance, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineMar 19, 2018Variant classified as Uncertain Significance - Favor Pathogenic. The Ser326Thr v ariant in LMNA has been reported in 7 individuals with a range of cardio-muscula r manifestations, including 5 individuals with DCM and/or conduction system dise ase (CSD), 1 with late-onset scapular myopathy and CSD, and 1 with early-onset X -linked EDMD that also carried a pathogenic EMD variant (Muntoni 2006, Meune 200 6, Ito 2017, Hasselberg 2018). This variant has also been identified in 15/12614 6 European chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad .broadinstitute.org; dbSNP rs56851164). In vitro functional studies provide some evidence that the p.Ser326Thr variant may not impact protein function (Gangemi 2013). However, these types of assays may not accurately represent biological fu nction. In addition, serine (Ser) at position 326 is not conserved in evolution with 5 species carrying a threonine (Thr), suggesting that this change may be to lerated. In summary, while there is some suspicion for a pathogenic role, the cl inical significance of the p.Ser326Thr variant is uncertain due to conflicting e vidence. ACMG/AMP Criteria applied: PM6; PS4; BP4, BS3_Supporting. -
Dilated cardiomyopathy 1A Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingInstitute of Immunology and Genetics KaiserslauternFeb 02, 2024ACMG Criteria: PM2_P, PP5; Variant was found in heterozygous state -
Uncertain significance, criteria provided, single submitterclinical testingEquipe Genetique des Anomalies du Developpement, Université de BourgogneNov 21, 2018- -
Primary familial hypertrophic cardiomyopathy Pathogenic:1
Likely pathogenic, flagged submissionclinical testingBlueprint GeneticsSep 14, 2015- -
Cardiomyopathy Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingColor Diagnostics, LLC DBA Color HealthDec 15, 2022This missense variant replaces serine with threonine at codon 326 of the lamin A/C proteins. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with unspecified LMNA-associated muscular phenotype (PMID: 16407522), and in three unrelated individuals affected with dilated cardiomyopathy (PMID: 24503780, 27532257, 29095976). This variant has been reported as de novo in an individual affected with Emery-Dreifuss muscular dystrophy (PMID: 16585054). This and two other affected individuals from this family carried a pathogenic p.Tyr105* variant in the same gene. This variant has been reported in three additional individuals affected with Emery-Dreifuss muscular dystrophy, one individual affected with late-onset scapular myopathy and two individuals affected with dilated cardiomyopathy (PMID: 16585054). This variant has also been identified in 15/281330 chromosomes in the general population by the Genome Aggregation Database (gnomAD). In summary, this is a variant of unknown impact on function that has been observed in affected individuals as well as in the general population. Available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Primary dilated cardiomyopathy Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAll of Us Research Program, National Institutes of HealthDec 18, 2023This missense variant replaces serine with threonine at codon 326 of the lamin A/C proteins. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with unspecified LMNA-associated muscular phenotype (PMID: 16407522), and in three unrelated individuals affected with dilated cardiomyopathy (PMID: 24503780, 27532257, 29095976). This variant has been reported as de novo in an individual affected with Emery-Dreifuss muscular dystrophy (PMID: 16585054). This and two other affected individuals from this family carried a pathogenic p.Tyr105* variant in the same gene. This variant has been reported in three additional individuals affected with Emery-Dreifuss muscular dystrophy, one individual affected with late-onset scapular myopathy and two individuals affected with dilated cardiomyopathy (PMID: 16585054). This variant has also been identified in 15/281330 chromosomes in the general population by the Genome Aggregation Database (gnomAD). In summary, this is a variant of unknown impact on function that has been observed in affected individuals as well as in the general population. Available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Cardiovascular phenotype Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsAug 24, 2022The p.S326T variant (also known as c.976T>A), located in coding exon 6 of the LMNA gene, results from a T to A substitution at nucleotide position 976. The serine at codon 326 is replaced by threonine, an amino acid with similar properties. This alteration has been detected in individuals reported to have conduction system disease and various myopathies, including dilated cardiomyopathy, late-onset scapular myopathy, and Emery-Dreifuss muscular dystrophy; however, some patients had variants in other genes and, in some cases, clinical detail and/or gene analysis were limited (Muntoni F et al. Brain. 2006;129:1260-8; Hasselberg NE et al. Eur Heart J. 2018 03;39(10):853-860Pugh TJ et al. Genet. Med. 2014;16:601-8; Peretto G et al. Ann Intern Med. 2019 10;171(7):458-463). This variant has also been detected in a hypertrophic cardiomyopathy genetic testing cohort and in cohorts not selected for the presence of LMNA-related disease, but clinical details were limited (Florwick A et al. Front Genet. 2017;8:79; Thauvin-Robinet C et al. Eur J Hum Genet. 2019 08;27(8):1197-1214; Hathaway J et al. BMC Cardiovasc Disord. 2021 03;21(1):126). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Charcot-Marie-Tooth disease type 2 Benign:1
Likely benign, criteria provided, single submitterclinical testingInvitaeJan 11, 2024- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.075
CardioboostCm
Uncertain
0.60
BayesDel_addAF
Benign
-0.018
T
BayesDel_noAF
Uncertain
-0.030
CADD
Benign
18
DANN
Benign
0.32
DEOGEN2
Uncertain
0.54
.;.;.;D;.;.;.;.
Eigen
Benign
-0.81
Eigen_PC
Benign
-0.62
FATHMM_MKL
Benign
0.33
N
LIST_S2
Benign
0.83
T;T;T;T;T;T;T;T
M_CAP
Benign
0.029
D
MetaRNN
Uncertain
0.55
D;D;D;D;D;D;D;D
MetaSVM
Benign
-0.99
T
MutationAssessor
Benign
-0.77
N;.;N;N;N;.;.;.
MutationTaster
Benign
0.65
D;D;D;D;D;N;N;N;N
PrimateAI
Benign
0.46
T
PROVEAN
Benign
0.55
N;N;N;N;N;N;N;N
REVEL
Uncertain
0.48
Sift
Benign
1.0
T;T;T;T;T;T;T;T
Sift4G
Benign
0.62
T;T;T;T;T;T;T;T
Polyphen
0.0
B;.;B;B;.;.;B;.
Vest4
0.61
MutPred
0.76
Loss of MoRF binding (P = 0.1256);Loss of MoRF binding (P = 0.1256);Loss of MoRF binding (P = 0.1256);Loss of MoRF binding (P = 0.1256);Loss of MoRF binding (P = 0.1256);.;.;.;
MVP
0.99
MPC
0.87
ClinPred
0.020
T
GERP RS
3.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8
Varity_R
0.072
gMVP
0.87

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs56851164; hg19: chr1-156105731; API