rs879253934

chr1-156136216-T-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP2 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

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 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, 12 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 chr1-156136215-C-G is described in Lovd as [Pathogenic].
• PP2: Missense variant where missense usually causes diseases, LMNA
• 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 submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LMNA	NM_170707.4	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	7/12	ENST00000368300.9
LMNA	NM_005572.4	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	7/10	ENST00000677389.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LMNA	ENST00000368300.9	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	7/12	1	NM_170707.4	P1
LMNA	ENST00000677389.1	c.1160T>C	p.Leu387Pro	missense_variant, splice_region_variant	7/10		NM_005572.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Aug 09, 2022

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. ClinVar contains an entry for this variant (Variation ID: 245759). 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

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 24, 2015

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
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;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
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

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

Publications

LitVar

Other links and lift over

dbSNP: rs879253934; hg19: chr1-156106007;