rs773444127

chr19-2435144-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PP3_Strong

The NM_032737.4(LMNB2):c.712G>A(p.Glu238Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000227 in 1,452,324 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. E238V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: LMNB2 NM_032737.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.76

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.949

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LMNB2	NM_032737.4	c.712G>A	p.Glu238Lys	missense_variant	5/12	ENST00000325327.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LMNB2	ENST00000325327.4	c.712G>A	p.Glu238Lys	missense_variant	5/12	1	NM_032737.4	P1
LMNB2	ENST00000527409.1	n.348G>A		non_coding_transcript_exon_variant	2/4	5
LMNB2	ENST00000534495.1	n.350G>A		non_coding_transcript_exon_variant	2/2	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000211 AC: 5 AN: 236526 Hom.: 0 AF XY: 0.0000154 AC XY: 2 AN XY: 129838

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000583

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000328

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000186

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000227 AC: 33 AN: 1452324 Hom.: 0 Cov.: 39 AF XY: 0.0000166 AC XY: 12 AN XY: 722858

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000252

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000284 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.0000166 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Lipodystrophy, partial, acquired, susceptibility to;C4225289:Progressive myoclonic epilepsy type 9 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 22, 2020

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. 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, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with LMNB2-related disease. This variant is present in population databases (rs773444127, ExAC 0.003%). This sequence change replaces glutamic acid with lysine at codon 238 of the LMNB2 protein (p.Glu238Lys). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and lysine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
Cadd	Pathogenic	34
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	0.94	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.69	T
REVEL	Pathogenic	0.83
Sift4G	Uncertain	0.0060	D
Vest4		0.82
MVP		0.62
MPC		0.91
ClinPred		0.98	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.55
gMVP		0.22

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs773444127; hg19: chr19-2435142; COSMIC: COSV57591298; COSMIC: COSV57591298;