chr3-123734012-C-A

Variant names:

• chr3-123734012-C-A
• rs115018449
• NM_053025.4:c.984G>T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_053025.4(MYLK):​c.984G>T​(p.Ser328Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,868 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. S328S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MYLK NM_053025.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -1.08
• Publications: 3 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 Gene-Disease associations (from GenCC):

• aortic aneurysm, familial thoracic 7

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen
• megacystis-microcolon-intestinal hypoperistalsis syndrome 1

  Inheritance: AR Classification: STRONG Submitted by: G2P
• connective tissue disorder

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• megacystis-microcolon-intestinal hypoperistalsis syndrome

  Inheritance: AD, AR Classification: SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.71).
• BP6: Variant 3-123734012-C-A is Benign according to our data. Variant chr3-123734012-C-A is described in ClinVar as Likely_benign. ClinVar VariationId is 2963330.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-1.08 with no splicing effect.

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.984G>T	p.Ser328Ser	synonymous	Exon 10 of 34	NP_444253.3
	MYLK	NM_053027.4		c.984G>T	p.Ser328Ser	synonymous	Exon 10 of 33	NP_444255.3
	MYLK	NM_053026.4		c.984G>T	p.Ser328Ser	synonymous	Exon 10 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.984G>T	p.Ser328Ser	synonymous	Exon 10 of 34	ENSP00000353452.3
	MYLK	ENST00000464489.5	TSL:1	n.*563G>T		non_coding_transcript_exon	Exon 9 of 33	ENSP00000417798.1
	MYLK	ENST00000464489.5	TSL:1	n.*563G>T		3_prime_UTR	Exon 9 of 33	ENSP00000417798.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000804 AC: 2 AN: 248734 AF XY: 0.00000742

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: 0.00000899

Gnomad OTH exome AF: 0.000164

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461868 Hom.: 0 Cov.: 54 AF XY: 0.00000138 AC XY: 1 AN XY: 727230

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

American (AMR) AF: 0.0000224 AC: 1 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: 86244

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

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

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Aortic aneurysm, familial thoracic 7 Benign:1

Jun 16, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.71
CADD	Benign	0.025
DANN	Benign	0.55
PhyloP100		-1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs115018449; hg19: chr3-123452859;