rs60446065

Variant names:

• chr1-156115045-G-A
• rs60446065
• NM_170707.4:c.127G>A

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_170707.4(LMNA):​c.127G>A​(p.Ala43Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000692 in 1,444,852 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/23 in silico tools predict a damaging 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. A43E) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: LMNA NM_170707.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1 O:1
• Conservation: PhyloP100: 9.95
• Publications: 5 publications found

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]

LMNA Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1A

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet
• familial partial lipodystrophy, Dunnigan type

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
• Hutchinson-Gilford progeria syndrome

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• restrictive dermopathy 2

  Inheritance: AR, AD Classification: DEFINITIVE, LIMITED Submitted by: G2P
• Emery-Dreifuss muscular dystrophy 2, autosomal dominant

  Inheritance: SD, AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• atrioventricular block

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• heart-hand syndrome, Slovenian type

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, G2P
• Charcot-Marie-Tooth disease type 2B1

  Inheritance: AR, AD Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: G2P, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)
• Emery-Dreifuss muscular dystrophy 3, autosomal recessive

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• mandibuloacral dysplasia with type A lipodystrophy

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• atrial fibrillation

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• atypical Werner syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal dominant Emery-Dreifuss muscular dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• congenital muscular dystrophy due to LMNA mutation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• lethal restrictive dermopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• LMNA-related cardiocutaneous progeria syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive Emery-Dreifuss muscular dystrophy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy-hypergonadotropic hypogonadism syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal semi-dominant severe lipodystrophic laminopathy

  Inheritance: SD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 28 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 23 uncertain in NM_170707.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-156115046-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 1457766.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989
• PP5: Variant 1-156115045-G-A is Pathogenic according to our data. Variant chr1-156115045-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 66799.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNA	NM_170707.4	c.127G>A	p.Ala43Thr	missense_variant	Exon 1 of 12	ENST00000368300.9	NP_733821.1
LMNA	NM_005572.4	c.127G>A	p.Ala43Thr	missense_variant	Exon 1 of 10	ENST00000677389.1	NP_005563.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LMNA	ENST00000368300.9	c.127G>A	p.Ala43Thr	missense_variant	Exon 1 of 12	1	NM_170707.4	ENSP00000357283.4
LMNA	ENST00000677389.1	c.127G>A	p.Ala43Thr	missense_variant	Exon 1 of 10		NM_005572.4	ENSP00000503633.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.92e-7 AC: 1 AN: 1444852 Hom.: 0 Cov.: 31 AF XY: 0.00000139 AC XY: 1 AN XY: 717142

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33098

American (AMR) AF: 0.00 AC: 0 AN: 42406

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25728

East Asian (EAS) AF: 0.00 AC: 0 AN: 38792

South Asian (SAS) AF: 0.00 AC: 0 AN: 83522

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51910

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5748

European-Non Finnish (NFE) AF: 9.06e-7 AC: 1 AN: 1103958

Other (OTH) AF: 0.00 AC: 0 AN: 59690

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:1 Other:1

-

Epithelial Biology; Institute of Medical Biology, Singapore

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Jan 10, 2017

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The A43T variant has been reported previously in an individual with Emery-Dreifuss muscular dystrophy (EDMD) type 2 who was heterozygous for this change and did not have another identifiable LMNA variant; however, information about parental testing was not provided and functional characterization of the variant was not performed (Brown et al., 2001). It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The A43T variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. Additionally, this substitution occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. Furthermore, multiple missense variants in nearby residues have been reported in the Human Gene Mutation Database in association with LMNA-related disorders (Stenson et al., 2014), supporting the functional importance of this region of the protein. Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -

Apr 03, 2018

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Feb 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 43 of the LMNA protein (p.Ala43Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of muscular dystrophy (PMID: 11503164; Invitae). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 66799). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt LMNA protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects LMNA function (PMID: 34862408). This variant disrupts the p.Ala43 amino acid residue in LMNA. Other variant(s) that disrupt this residue have been observed in individuals with LMNA-related conditions (PMID: 28688748), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.98	.;.;.;D;.
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D
M_CAP	Pathogenic	0.71	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.8	H;.;H;H;H
PhyloP100		10
PrimateAI	Uncertain	0.76	T
PROVEAN	Uncertain	-3.5	D;D;D;D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Uncertain	0.021	D;D;D;D;D
Polyphen		1.0	D;.;D;D;.
Vest4		0.96
MutPred		0.92		Gain of phosphorylation at A43 (P = 0.0767);Gain of phosphorylation at A43 (P = 0.0767);Gain of phosphorylation at A43 (P = 0.0767);Gain of phosphorylation at A43 (P = 0.0767);Gain of phosphorylation at A43 (P = 0.0767);
MVP		0.99
MPC		2.1
ClinPred		1.0	D
GERP RS		4.8
PromoterAI		-0.014	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.86
gMVP		0.99
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs60446065; hg19: chr1-156084836;