rs587777677

Variant names:

• chr18-7050692-A-C
• rs587777677
• NM_005559.4:c.588+2T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_005559.4(LAMA1):​c.588+2T>G variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: LAMA1 NM_005559.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 8.95
• Publications: 2 publications found

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)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0263329 fraction of the gene. Cryptic splice site detected, with MaxEntScore 9, offset of 4, new splice context is: gagGTatgg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-7050692-A-C is Pathogenic according to our data. Variant chr18-7050692-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 144107.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA1	NM_005559.4	c.588+2T>G		splice_donor_variant, intron_variant	Intron 4 of 62	ENST00000389658.4	NP_005550.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA1	ENST00000389658.4	c.588+2T>G		splice_donor_variant, intron_variant	Intron 4 of 62	1	NM_005559.4	ENSP00000374309.3
LAMA1	ENST00000579014.5	n.627+2T>G		splice_donor_variant, intron_variant	Intron 4 of 61	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Ataxia - intellectual disability - oculomotor apraxia - cerebellar cysts syndrome Pathogenic:2

Aug 07, 2014

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Nov 25, 2014

Dobyns Lab, Seattle Children's Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.20
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		8.9
GERP RS		5.6
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.74		Position offset: -2
DS_DL_spliceai		0.99		Position offset: 2

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

Other links and lift over

dbSNP: rs587777677; hg19: chr18-7050691;