chr9-133518869-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001080483.3(MYMK):​c.399+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.0000354 in 1,610,778 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

MYMK
NM_001080483.3 splice_donor_5th_base, intron

Scores

2
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.68
Variant links:
Genes affected
MYMK (HGNC:33778): (myomaker, myoblast fusion factor) Involved in myoblast fusion. Located in plasma membrane. Implicated in Carey-Fineman-Ziter syndrome. [provided by Alliance of Genome Resources, Apr 2022]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MYMKNM_001080483.3 linkuse as main transcriptc.399+5G>A splice_donor_5th_base_variant, intron_variant ENST00000339996.4

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MYMKENST00000339996.4 linkuse as main transcriptc.399+5G>A splice_donor_5th_base_variant, intron_variant 2 NM_001080483.3 P1
MYMKENST00000413714.1 linkuse as main transcriptn.454+5G>A splice_donor_5th_base_variant, intron_variant, non_coding_transcript_variant 3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152128
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000203
AC:
5
AN:
246046
Hom.:
0
AF XY:
0.0000225
AC XY:
3
AN XY:
133366
show subpopulations
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:
0.0000327
Gnomad FIN exome
AF:
0.0000999
Gnomad NFE exome
AF:
0.0000181
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000384
AC:
56
AN:
1458650
Hom.:
0
Cov.:
31
AF XY:
0.0000372
AC XY:
27
AN XY:
725644
show subpopulations
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:
0.0000464
Gnomad4 FIN exome
AF:
0.0000390
Gnomad4 NFE exome
AF:
0.0000441
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152128
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74304
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Congenital nonprogressive myopathy with Moebius and Robin sequences Uncertain:1
Uncertain significance, criteria provided, single submitterresearchBroad Center for Mendelian Genomics, Broad Institute of MIT and HarvardDec 03, 2018The heterozygous c.399+5G>A variant in TMEM8C was identified by our study in the compound heterozygous state, with a likely pathogenic variant, in one individual with Carey-Finteman-Ziter syndrome. The presence of this variant in combination with a pathogenic variant and in an individual with Carey-Finteman-Ziter syndrome increases the likelihood that the c.399+5G>A variant is pathogenic. This variant is located in the 5' splice region. Computational tools do suggest an impact to splicing as well as a frameshift leading to nonsense mediated decay and an abnormal or truncated protein. No likely pathogenic or pathogenic loss of function variants in the MYMK (alternative name for TMEM8C) gene have been reported in ClinVar, though knock-out animal models in zebrafish do have a phenotype that matches aspects of Carey-Finteman-Ziter syndrome (PMID: 30016436). In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM2, PP3, PM3_Supporting (Richards 2015). -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGeneDxOct 16, 2019Has not been previously published as pathogenic or benign to our knowledge; In-silico analysis, which includes splice predictors and evolutionary conservation, is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 32528171) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.36
CADD
Uncertain
25
DANN
Benign
0.86

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
1.0
SpliceAI score (max)
0.96
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.34
Position offset: 9
DS_DL_spliceai
0.96
Position offset: 5

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs755976471; hg19: chr9-136383991; API