19-2434029-C-A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_032737.4(LMNB2):c.1279G>T(p.Ala427Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000138 in 1,451,270 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A427T) has been classified as Benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

LMNB2
NM_032737.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -2.01

Publications

4 publications found

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 Gene-Disease associations (from GenCC):

microcephaly 27, primary, autosomal dominant
Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
progressive myoclonic epilepsy type 9
Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
microcephaly
Inheritance: AD Classification: MODERATE Submitted by: Franklin by Genoox
lipodystrophy, partial, acquired, susceptibility to
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
central nervous system malformation
Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

LMNB2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.06239769).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNB2	NM_032737.4 link	c.1279G>T	p.Ala427Ser	missense_variant	Exon 8 of 12	ENST00000325327.4	NP_116126.3	Q03252

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
LMNB2	ENST00000325327.4 link	c.1279G>T	p.Ala427Ser	missense_variant	Exon 8 of 12	1	NM_032737.4	ENSP00000327054.3	Q03252
LMNB2	ENST00000490554.5 link	n.470G>T		non_coding_transcript_exon_variant	Exon 3 of 4	2
LMNB2	ENST00000532465.1 link	n.-130G>T		upstream_gene_variant		3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000134

AC:

AN:

223678

AF XY:

0.0000162

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000177

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000138

AC:

AN:

1451270

Hom.:

Cov.:

AF XY:

0.00000277

AC XY:

AN XY:

721686

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33264

American (AMR)

AF:

0.00

AC:

AN:

43340

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25942

East Asian (EAS)

AF:

0.0000508

AC:

AN:

39360

South Asian (SAS)

AF:

0.00

AC:

AN:

85554

European-Finnish (FIN)

AF:

0.00

AC:

AN:

49736

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5684

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1108498

Other (OTH)

AF:

0.00

AC:

AN:

59892

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000836

AC:

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

Nov 12, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine with serine at codon 427 of the LMNB2 protein (p.Ala427Ser). The alanine residue is weakly conserved and there is a moderate physicochemical difference between alanine and serine. This variant is present in population databases (rs57521499, ExAC 0.02%). This variant has not been reported in the literature in individuals with LMNB2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The serine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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

AlphaMissense

Benign

0.069

BayesDel_addAF

Benign

-0.26

BayesDel_noAF

Benign

-0.33

CADD

Benign

0.028

(source)

DANN

Benign

0.29

DEOGEN2

Benign

0.21

Eigen

Benign

-1.5

Eigen_PC

Benign

-1.6

FATHMM_MKL

Benign

0.13

LIST_S2

Benign

0.34

M_CAP

Benign

0.021

MetaRNN

Benign

0.062

MetaSVM

Benign

-1.1

PhyloP100

-2.0

PrimateAI

Benign

0.27

REVEL

Benign

0.015

Sift4G

Benign

0.79

Vest4

0.12

MVP

0.36

MPC

0.23

ClinPred

0.027

GERP RS

-4.8

Varity_R

0.030

gMVP

0.31

Mutation Taster

=83/17

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over