chr3-123626842-C-G

Position:

• chr3-123626842-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP2

The NM_053025.4(MYLK):​c.5214G>C​(p.Lys1738Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000123 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: MYLK NM_053025.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.296

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]

MYLK-AS1 (HGNC:42440): (MYLK antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 1 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYLK	NM_053025.4	c.5214G>C	p.Lys1738Asn	missense_variant	31/34	ENST00000360304.8	NP_444253.3
MYLK-AS1	NR_038266.2	n.290-2652C>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYLK	ENST00000360304.8	c.5214G>C	p.Lys1738Asn	missense_variant	31/34	5	NM_053025.4	ENSP00000353452	P4
MYLK-AS1	ENST00000485162.5	n.261-2652C>G		intron_variant, non_coding_transcript_variant		4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251484 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135918

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1461880 Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10 AN XY: 727242

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: 0.0000162

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

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

Sep 01, 2021

This sequence change replaces lysine with asparagine at codon 1738 of the MYLK protein (p.Lys1738Asn). The lysine residue is highly conserved and there is a moderate physicochemical difference between lysine and asparagine. This variant is present in population databases (rs761266023, ExAC 0.001%). This variant has not been reported in the literature in individuals affected with MYLK-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Benign	-0.032	T
BayesDel_noAF	Benign	-0.28
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.53	.;.;.;D;.;D
Eigen	Benign	0.10
Eigen_PC	Benign	0.026
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.94	.;D;D;D;.;.
M_CAP	Benign	0.042	D
MetaRNN	Uncertain	0.46	T;T;T;T;T;T
MetaSVM	Benign	-0.43	T
MutationAssessor	Benign	2.0	.;.;.;M;.;M
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-3.3	D;.;D;D;D;D
REVEL	Benign	0.26
Sift	Benign	0.052	T;.;T;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D;D;D
Polyphen		1.0	D;D;D;D;D;D
Vest4		0.62
MutPred		0.36		.;.;.;Loss of methylation at K1738 (P = 0.012);.;Loss of methylation at K1738 (P = 0.012);
MVP		0.86
MPC		1.0
ClinPred		0.64	D
GERP RS		0.28
Varity_R		0.21
gMVP		0.91

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: rs761266023; hg19: chr3-123345689;