rs797045183

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1PM2

The NM_005559.4(LAMA1):​c.8557-1G>C variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000205 in 1,461,870 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

LAMA1
NM_005559.4 splice_acceptor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.25

Publications

2 publications found
Variant links:
Genes affected
LAMA1 (HGNC:6481): (laminin subunit alpha 1) This gene encodes one of the alpha 1 subunits of laminin. The laminins are a family of extracellular matrix glycoproteins that have a heterotrimeric structure consisting of an alpha, beta and gamma chain. These proteins make up a major component of the basement membrane and have been implicated in a wide variety of biological processes including cell adhesion, differentiation, migration, signaling, neurite outgrowth and metastasis. Mutations in this gene may be associated with Poretti-Boltshauser syndrome. [provided by RefSeq, Sep 2014]
LAMA1 Gene-Disease associations (from GenCC):
  • ataxia - intellectual disability - oculomotor apraxia - cerebellar cysts syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 6.1, offset of 11, new splice context is: ttggcttacatcacccacAGcat. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMA1NM_005559.4 linkc.8557-1G>C splice_acceptor_variant, intron_variant Intron 59 of 62 ENST00000389658.4 NP_005550.2 P25391

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA1ENST00000389658.4 linkc.8557-1G>C splice_acceptor_variant, intron_variant Intron 59 of 62 1 NM_005559.4 ENSP00000374309.3 P25391
LAMA1ENST00000488064.5 linkn.1964-1G>C splice_acceptor_variant, intron_variant Intron 10 of 13 2
LAMA1ENST00000492048.5 linkn.1445-1G>C splice_acceptor_variant, intron_variant Intron 3 of 6 2
LAMA1ENST00000579014.5 linkn.9572-1G>C splice_acceptor_variant, intron_variant Intron 58 of 61 2

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461870
Hom.:
0
Cov.:
32
AF XY:
0.00000413
AC XY:
3
AN XY:
727232
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
33

ClinVar

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

Submissions by phenotype

Ataxia - intellectual disability - oculomotor apraxia - cerebellar cysts syndrome Uncertain:1
Nov 25, 2014
Dobyns Lab, Seattle Children's Research Institute
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

Two maternal variants; not enough info to determine which pathogenic -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.40
CADD
Pathogenic
34
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.99
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
6.3
GERP RS
5.5
Mutation Taster
=7/93
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
0.98
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.91
Position offset: -12
DS_AL_spliceai
0.98
Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs797045183; hg19: chr18-6948556; API