Genetic Variant LMNB2:c.1202+4C>G (chr19-2434291-G-C) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_032737.4(LMNB2):c.1202+4C>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,096 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

LMNB2
NM_032737.4 splice_region, intron

Scores

Splicing: ADA: 0.0005972

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.0350

Variant links:

Genes affected

LMNB2 (HGNC:6638): (lamin B2) This gene encodes a B type nuclear lamin. The nuclear lamina consists of 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. Mutations in this gene are associated with acquired partial lipodystrophy. [provided by RefSeq, May 2012]

LMNB2 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.68).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNB2	NM_032737.4 link	c.1202+4C>G		splice_region_variant, intron_variant	Intron 7 of 11	ENST00000325327.4	NP_116126.3	Q03252

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL	MANE	Protein	UniProt
LMNB2	ENST00000325327.4 link	c.1202+4C>G	splice_region_variant, intron_variant	Intron 7 of 11	1	NM_032737.4	ENSP00000327054.3	Q03252
LMNB2	ENST00000490554.5 link	n.393+4C>G	splice_region_variant, intron_variant	Intron 2 of 3	2
LMNB2	ENST00000527409.1 link	n.*4C>G	downstream_gene_variant		5

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000402

AC:

AN:

249028

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135200

show subpopulations

Gnomad AFR exome

AF:

0.00

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:

0.00

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460096

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726346

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000468

Hom.:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Lipodystrophy, partial, acquired, susceptibility to;C4225289:Progressive myoclonic epilepsy type 9

Uncertain:1

Feb 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 7 of the LMNB2 gene. It does not directly change the encoded amino acid sequence of the LMNB2 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (no rsID available, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with LMNB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 568398). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.68

CADD

Benign

DANN

Benign

0.86

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00060

dbscSNV1_RF

Benign

0.090

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over