rs148060790

Variant summary

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

The NM_000426.4(LAMA2):​c.4959+6G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,612,004 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: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 splice_region, intron

Scores

2
Splicing: ADA: 0.009949
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.75

Publications

0 publications found
Variant links:
Genes affected
LAMA2 (HGNC:6482): (laminin subunit alpha 2) Laminin, an extracellular protein, is a major component of the basement membrane. It is thought to mediate the attachment, migration, and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components. It is composed of three subunits, alpha, beta, and gamma, which are bound to each other by disulfide bonds into a cross-shaped molecule. This gene encodes the alpha 2 chain, which constitutes one of the subunits of laminin 2 (merosin) and laminin 4 (s-merosin). Mutations in this gene have been identified as the cause of congenital merosin-deficient muscular dystrophy. Two transcript variants encoding different proteins have been found for this gene. [provided by RefSeq, Jul 2008]
LAMA2 Gene-Disease associations (from GenCC):
  • congenital merosin-deficient muscular dystrophy 1A
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, G2P
  • LAMA2-related muscular dystrophy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • muscular dystrophy, limb-girdle, autosomal recessive 23
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

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 (BayesDel_noAF=-0.47).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMA2NM_000426.4 linkc.4959+6G>A splice_region_variant, intron_variant Intron 34 of 64 ENST00000421865.3 NP_000417.3
LAMA2NM_001079823.2 linkc.4959+6G>A splice_region_variant, intron_variant Intron 34 of 63 NP_001073291.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA2ENST00000421865.3 linkc.4959+6G>A splice_region_variant, intron_variant Intron 34 of 64 5 NM_000426.4 ENSP00000400365.2
LAMA2ENST00000618192.5 linkc.5223+6G>A splice_region_variant, intron_variant Intron 35 of 65 5 ENSP00000480802.2
LAMA2ENST00000617695.5 linkc.4959+6G>A splice_region_variant, intron_variant Intron 34 of 63 5 ENSP00000481744.2
LAMA2ENST00000687590.1 linkn.1379+6G>A splice_region_variant, intron_variant Intron 2 of 4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1459834
Hom.:
0
Cov.:
30
AF XY:
0.0000151
AC XY:
11
AN XY:
726410
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33422
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39662
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86204
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53378
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000144
AC:
16
AN:
1110242
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60328
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74336
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

LAMA2-related muscular dystrophy Uncertain:1
Nov 30, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 34 of the LAMA2 gene. It does not directly change the encoded amino acid sequence of the LAMA2 protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with LAMA2-related conditions. 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
-0.47
CADD
Benign
14
DANN
Benign
0.93
PhyloP100
1.8

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.0099
dbscSNV1_RF
Benign
0.094
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

Other links and lift over

dbSNP: rs148060790; hg19: chr6-129691141; API