3-123733012-G-C

Position:

• chr3-123733012-G-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP2 BP4_Strong

The NM_053025.4(MYLK):​c.1400C>G​(p.Ala467Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000889 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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: 0.0000089 (0 hom.)
• Consequence: MYLK NM_053025.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.174

Genes affected

MYLK (HGNC:7590): (myosin light chain kinase) This gene, a muscle member of the immunoglobulin gene superfamily, encodes myosin light chain kinase which is a calcium/calmodulin dependent enzyme. This kinase phosphorylates myosin regulatory light chains to facilitate myosin interaction with actin filaments to produce contractile activity. This gene encodes both smooth muscle and nonmuscle isoforms. In addition, using a separate promoter in an intron in the 3' region, it encodes telokin, a small protein identical in sequence to the C-terminus of myosin light chain kinase, that is independently expressed in smooth muscle and functions to stabilize unphosphorylated myosin filaments. A pseudogene is located on the p arm of chromosome 3. Four transcript variants that produce four isoforms of the calcium/calmodulin dependent enzyme have been identified as well as two transcripts that produce two isoforms of telokin. Additional variants have been identified but lack full length transcripts. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYLK. . Gene score misZ 1.1317 (greater than the threshold 3.09). Trascript score misZ 3.1503 (greater than threshold 3.09). GenCC has associacion of gene with familial thoracic aortic aneurysm and aortic dissection, connective tissue disorder, megacystis-microcolon-intestinal hypoperistalsis syndrome, aortic aneurysm, familial thoracic 7.
• BP4: Computational evidence support a benign effect (MetaRNN=0.025414377).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYLK	NM_053025.4	c.1400C>G	p.Ala467Gly	missense_variant	11/34	ENST00000360304.8	NP_444253.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYLK	ENST00000360304.8	c.1400C>G	p.Ala467Gly	missense_variant	11/34	5	NM_053025.4	ENSP00000353452	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251160 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135738

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000889 AC: 13 AN: 1461866 Hom.: 0 Cov.: 36 AF XY: 0.0000110 AC XY: 8 AN XY: 727228

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000989

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

Aortic aneurysm, familial thoracic 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 15, 2016

In summary, this is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). However, the glycine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a MYLK-related disease. This sequence change replaces alanine with glycine at codon 467 of the MYLK protein (p.Ala467Gly). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and glycine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.47	T
BayesDel_noAF	Benign	-0.74
CADD	Benign	3.9
DANN	Benign	0.80
DEOGEN2	Benign	0.17	.;.;T;T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.025	N
LIST_S2	Benign	0.62	.;T;T;.
M_CAP	Benign	0.0096	T
MetaRNN	Benign	0.025	T;T;T;T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	-0.73	N;N;N;N
MutationTaster	Benign	1.0	N;N;N;N;N
PrimateAI	Benign	0.25	T
PROVEAN	Benign	0.92	N;N;N;N
REVEL	Benign	0.14
Sift	Benign	0.54	T;T;T;T
Sift4G	Benign	0.93	T;T;T;T
Polyphen		0.0	B;B;B;B
Vest4		0.069
MutPred		0.37		Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);
MVP		0.26
MPC		0.61
ClinPred		0.082	T
GERP RS		-5.6
Varity_R		0.14
gMVP		0.13

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

LitVar

Other links and lift over

dbSNP: rs878855175; hg19: chr3-123451859;