12-22055280-A-G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_018686.6(CMAS):​c.392A>G​(p.Asn131Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000025 in 1,602,946 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CMAS
NM_018686.6 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.423

Publications

0 publications found
Variant links:
Genes affected
CMAS (HGNC:18290): (cytidine monophosphate N-acetylneuraminic acid synthetase) This gene encodes an enzyme that converts N-acetylneuraminic acid (NeuNAc) to cytidine 5'-monophosphate N-acetylneuraminic acid (CMP-NeuNAc). This process is important in the formation of sialylated glycoprotein and glycolipids. This modification plays a role in cell-cell communications and immune responses. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2016]
CMAS Gene-Disease associations (from GenCC):
  • intellectual disability
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.054665565).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CMASNM_018686.6 linkc.392A>G p.Asn131Ser missense_variant Exon 2 of 8 ENST00000229329.7 NP_061156.1 Q8NFW8-1
CMASNR_135117.2 linkn.478A>G non_coding_transcript_exon_variant Exon 2 of 7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CMASENST00000229329.7 linkc.392A>G p.Asn131Ser missense_variant Exon 2 of 8 1 NM_018686.6 ENSP00000229329.2 Q8NFW8-1
CMASENST00000534981.5 linkn.392A>G non_coding_transcript_exon_variant Exon 2 of 7 1 ENSP00000446239.1 Q8NFW8-2
CMASENST00000538498.1 linkc.-86A>G 5_prime_UTR_variant Exon 1 of 4 3 ENSP00000440605.1 F5GYM0
CMASENST00000535610.5 linkn.261-175A>G intron_variant Intron 1 of 4 5 ENSP00000439404.1 F5H296

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152224
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:
0.000192
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000407
AC:
1
AN:
246002
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000549
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000207
AC:
3
AN:
1450722
Hom.:
0
Cov.:
28
AF XY:
0.00000138
AC XY:
1
AN XY:
722080
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33090
American (AMR)
AF:
0.00
AC:
0
AN:
43906
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25918
East Asian (EAS)
AF:
0.0000505
AC:
2
AN:
39566
South Asian (SAS)
AF:
0.0000118
AC:
1
AN:
84994
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53376
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5750
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1104128
Other (OTH)
AF:
0.00
AC:
0
AN:
59994
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152224
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41466
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000192
AC:
1
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Feb 05, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.392A>G (p.N131S) alteration is located in exon 2 (coding exon 2) of the CMAS gene. This alteration results from a A to G substitution at nucleotide position 392, causing the asparagine (N) at amino acid position 131 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.070
BayesDel_addAF
Benign
-0.43
T
BayesDel_noAF
Benign
-0.68
CADD
Benign
14
DANN
Benign
0.83
DEOGEN2
Benign
0.092
T
Eigen
Benign
-0.73
Eigen_PC
Benign
-0.64
FATHMM_MKL
Benign
0.18
N
LIST_S2
Benign
0.77
T
M_CAP
Benign
0.0022
T
MetaRNN
Benign
0.055
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.26
N
PhyloP100
0.42
PrimateAI
Benign
0.34
T
PROVEAN
Benign
-1.1
N
REVEL
Benign
0.12
Sift
Benign
0.70
T
Sift4G
Benign
0.71
T
Polyphen
0.0
B
Vest4
0.070
MutPred
0.51
Loss of stability (P = 0.0885);
MVP
0.37
MPC
0.64
ClinPred
0.027
T
GERP RS
0.44
PromoterAI
-0.0016
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.022
gMVP
0.16
Mutation Taster
=99/1
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs771403320; hg19: chr12-22208214; API