chr3-123701502-C-T

Variant names:

• chr3-123701502-C-T
• rs758697820
• NM_053025.4:c.2398G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_053025.4(MYLK):​c.2398G>A​(p.Val800Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,602 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. V800F) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MYLK NM_053025.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.84
• Publications: 0 publications found

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)

LOC105369194 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_053025.4. 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
	MYLK	NM_053025.4	MANE Select	c.2398G>A	p.Val800Ile	missense	Exon 17 of 34	NP_444253.3
	MYLK	NM_053027.4		c.2398G>A	p.Val800Ile	missense	Exon 17 of 33	NP_444255.3
	MYLK	NM_053026.4		c.2191G>A	p.Val731Ile	missense	Exon 16 of 33	NP_444254.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYLK	ENST00000360304.8	TSL:5 MANE Select	c.2398G>A	p.Val800Ile	missense	Exon 17 of 34	ENSP00000353452.3
	MYLK	ENST00000504946.6	TSL:1	c.7G>A	p.Val3Ile	missense	Exon 1 of 4	ENSP00000510315.1
	MYLK	ENST00000464489.5	TSL:1	n.*1977G>A		non_coding_transcript_exon	Exon 16 of 33	ENSP00000417798.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251448 AF XY: 0.00000736

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461602 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727112

⚠️ 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: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5594

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111964

Other (OTH) AF: 0.00 AC: 0 AN: 60364

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000225 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.028	T
BayesDel_noAF	Benign	-0.28
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.20	T
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.014	T
MetaRNN	Uncertain	0.66	D
MetaSVM	Benign	-0.56	T
MutationAssessor	Benign	1.5	L
PhyloP100		5.8
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-0.27	N
REVEL	Benign	0.17
Sift	Benign	0.17	T
Sift4G	Pathogenic	0.0	D
Polyphen		0.93	P
Vest4		0.56
MutPred		0.64		Gain of catalytic residue at V800 (P = 0.0988)
MVP		0.79
MPC		0.21
ClinPred		0.79	D
GERP RS		5.2
PromoterAI		0.060	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.081
gMVP		0.50
Mutation Taster		=84/16	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: rs758697820; hg19: chr3-123420349;