chr18-23689909-C-A

Position:

• chr18-23689909-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_198129.4(LAMA3):​c.226C>A​(p.Pro76Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000116 in 1,381,842 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: LAMA3 NM_198129.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.682

Genes affected

LAMA3 (HGNC:6483): (laminin subunit alpha 3) The protein encoded by this gene belongs to the laminin family of secreted molecules. Laminins are heterotrimeric molecules that consist of alpha, beta, and gamma subunits that assemble through a coiled-coil domain. Laminins are essential for formation and function of the basement membrane and have additional functions in regulating cell migration and mechanical signal transduction. This gene encodes an alpha subunit and is responsive to several epithelial-mesenchymal regulators including keratinocyte growth factor, epidermal growth factor and insulin-like growth factor. Mutations in this gene have been identified as the cause of Herlitz type junctional epidermolysis bullosa and laryngoonychocutaneous syndrome. Alternative splicing and alternative promoter usage result in multiple transcript variants. [provided by RefSeq, Dec 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.12494108).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMA3	NM_198129.4	c.226C>A	p.Pro76Thr	missense_variant	1/75	ENST00000313654.14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMA3	ENST00000313654.14	c.226C>A	p.Pro76Thr	missense_variant	1/75	1	NM_198129.4	P1
LAMA3	ENST00000399516.7	c.226C>A	p.Pro76Thr	missense_variant	1/74	1
LAMA3	ENST00000585600.5	c.226C>A	p.Pro76Thr	missense_variant	1/13	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000116 AC: 16 AN: 1381842 Hom.: 0 Cov.: 31 AF XY: 0.0000117 AC XY: 8 AN XY: 681358

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000149

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 02, 2022

The c.226C>A (p.P76T) alteration is located in exon 1 (coding exon 1) of the LAMA3 gene. This alteration results from a C to A substitution at nucleotide position 226, causing the proline (P) at amino acid position 76 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.094
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.54
CADD	Benign	16
DANN	Benign	0.92
DEOGEN2	Benign	0.058	.;T
Eigen	Benign	-0.71
Eigen_PC	Benign	-0.80
FATHMM_MKL	Benign	0.38	N
LIST_S2	Benign	0.63	.;T
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.12	T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	0.94	N;N
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-3.8	D;D
REVEL	Benign	0.086
Sift	Benign	0.033	D;D
Vest4		0.28
MutPred		0.41		Gain of phosphorylation at P76 (P = 0.0124);Gain of phosphorylation at P76 (P = 0.0124);
MVP		0.21
MPC		1.9
ClinPred		0.47	T
GERP RS		2.3
gMVP		0.36

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr18-21269873;