chr3-123666266-T-C

Variant names:

• chr3-123666266-T-C
• rs1553788596
• NM_053025.4:c.3784A>G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_053025.4(MYLK):​c.3784A>G​(p.Thr1262Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MYLK NM_053025.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.148
• 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)

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10960588).
• BP6: Variant 3-123666266-T-C is Benign according to our data. Variant chr3-123666266-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 471727.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYLK	NM_053025.4	MANE Select	c.3784A>G	p.Thr1262Ala	missense	Exon 22 of 34	NP_444253.3
	MYLK	NM_053027.4		c.3784A>G	p.Thr1262Ala	missense	Exon 22 of 33	NP_444255.3
	MYLK	NM_053026.4		c.3577A>G	p.Thr1193Ala	missense	Exon 21 of 33	NP_444254.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYLK	ENST00000360304.8	TSL:5 MANE Select	c.3784A>G	p.Thr1262Ala	missense	Exon 22 of 34	ENSP00000353452.3
	MYLK	ENST00000464489.5	TSL:1	n.*3363A>G		non_coding_transcript_exon	Exon 21 of 33	ENSP00000417798.1
	MYLK	ENST00000464489.5	TSL:1	n.*3363A>G		3_prime_UTR	Exon 21 of 33	ENSP00000417798.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461894 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	-	Aortic aneurysm, familial thoracic 7 (1)
-	-	1	Familial thoracic aortic aneurysm and aortic dissection (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	0.056
DANN	Benign	0.27
DEOGEN2	Benign	0.22	T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.015	N
LIST_S2	Benign	0.61	T
M_CAP	Benign	0.0076	T
MetaRNN	Benign	0.11	T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	0.090	N
PhyloP100		0.15
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-0.24	N
REVEL	Benign	0.16
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.0	B
Vest4		0.057
MutPred		0.53		Gain of catalytic residue at T1262 (P = 0.0567)
MVP		0.41
MPC		0.15
ClinPred		0.020	T
GERP RS		-3.8
Varity_R		0.037
gMVP		0.088
Mutation Taster		=77/23	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: rs1553788596; hg19: chr3-123385113;