6-129445715-G-C

Variant names:

• chr6-129445715-G-C
• rs750999777
• NM_000426.4:c.6323G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000426.4(LAMA2):​c.6323G>C​(p.Arg2108Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,536 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R2108W) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LAMA2 NM_000426.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.77
• Publications: 0 publications found

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)

ENSG00000226149 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.823

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000426.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA2	NM_000426.4	MANE Select	c.6323G>C	p.Arg2108Pro	missense	Exon 45 of 65	NP_000417.3
	LAMA2	NM_001079823.2		c.6323G>C	p.Arg2108Pro	missense	Exon 45 of 64	NP_001073291.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA2	ENST00000421865.3	TSL:5 MANE Select	c.6323G>C	p.Arg2108Pro	missense	Exon 45 of 65	ENSP00000400365.2
	LAMA2	ENST00000618192.5	TSL:5	c.6587G>C	p.Arg2196Pro	missense	Exon 46 of 66	ENSP00000480802.2
	LAMA2	ENST00000617695.5	TSL:5	c.6323G>C	p.Arg2108Pro	missense	Exon 45 of 64	ENSP00000481744.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461536 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727072

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39662

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53350

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111810

Other (OTH) AF: 0.00 AC: 0 AN: 60378

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.056	T
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D
M_CAP	Benign	0.023	T
MetaRNN	Pathogenic	0.82	D
MetaSVM	Benign	-0.93	T
MutationAssessor	Uncertain	2.6	M
PhyloP100		7.8
PrimateAI	Uncertain	0.57	T
PROVEAN	Uncertain	-2.8	D
REVEL	Uncertain	0.47
Sift	Benign	0.18	T
Polyphen		1.0	D
Vest4		0.82
MutPred		0.57		Gain of ubiquitination at K2112 (P = 0.0467)
MVP		0.90
MPC		0.55
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.77
gMVP		0.82
Mutation Taster		=66/34	polymorphism

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

Other links and lift over

dbSNP: rs750999777; hg19: chr6-129766860;