1-156136216-T-C

Variant names:

• chr1-156136216-T-C
• rs879253934
• NM_170707.4:c.1160T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PP3_Moderate PP5

The NM_170707.4(LMNA):​c.1160T>C​(p.Leu387Pro) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. 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. L387V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: LMNA NM_170707.4 missense, splice_region
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 3.29
• Publications: 3 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: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 5 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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.886
• PP5: Variant 1-156136216-T-C is Pathogenic according to our data. Variant chr1-156136216-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 245759.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNA	NM_170707.4	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	Exon 7 of 12	ENST00000368300.9	NP_733821.1
LMNA	NM_005572.4	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	Exon 7 of 10	ENST00000677389.1	NP_005563.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LMNA	ENST00000368300.9	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	Exon 7 of 12	1	NM_170707.4	ENSP00000357283.4
LMNA	ENST00000677389.1	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	Exon 7 of 10		NM_005572.4	ENSP00000503633.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Aug 09, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 245759). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. This missense change has been observed in individual(s) with clinical features of autosomal dominant congenital muscular dystrophy (PMID: 33940562; Invitae). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 387 of the LMNA protein (p.Leu387Pro). -

not provided Uncertain:1

Apr 24, 2015

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The L387P variant has not been published as pathogenic or been reported as a benign polymorphism to our knowledge.The L387P variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Although the L387P variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties; this substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. Located within the tail region of the LMNA gene, a missense variant in the same residue (L387V) and missense variant in nearby residues (G382V, G382G, R388C, R388H) have been reported in the Human Gene Mutation Database (HGMD) in association with LMNA-related disorders (Stenson et al., 2009), supporting the functional importance of this region of the protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Uncertain	0.85
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.49
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	.;.;.;D;.;.;.;.;D
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Benign	0.84	T;T;T;T;T;T;T;T;T
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.6	M;.;M;M;M;.;.;.;.
PhyloP100		3.3
PrimateAI	Uncertain	0.79	T
PROVEAN	Pathogenic	-6.5	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.73
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;.;D;D;.;.;D;.;.
Vest4		0.96
MutPred		0.47		Loss of stability (P = 0.002);Loss of stability (P = 0.002);Loss of stability (P = 0.002);Loss of stability (P = 0.002);Loss of stability (P = 0.002);.;.;.;.;
MVP		0.99
MPC		2.6
ClinPred		0.99	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.3
Varity_R		0.91
gMVP		0.99
Mutation Taster		=15/85	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs879253934; hg19: chr1-156106007;