chr19-49830163-C-G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_030973.4(MED25):​c.764C>G​(p.Ala255Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000175 in 1,601,970 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 10/14 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

MED25
NM_030973.4 missense

Scores

1
8

Clinical Significance

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

Conservation

PhyloP100: 1.86

Publications

0 publications found
Variant links:
Genes affected
MED25 (HGNC:28845): (mediator complex subunit 25) This gene encodes a component of the transcriptional coactivator complex termed the Mediator complex. This complex is required for transcription of most RNA polymerase II-dependent genes. The encoded protein plays a role in chromatin modification and in preinitiation complex assembly. Mutations in this gene are associated with Charcot-Marie-Tooth disease type 2B2. [provided by RefSeq, Apr 2010]
MED25 Gene-Disease associations (from GenCC):
  • congenital cataract-microcephaly-nevus flammeus simplex-severe intellectual disability syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, G2P, Labcorp Genetics (formerly Invitae)
  • autosomal recessive non-syndromic intellectual disability
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Charcot-Marie-Tooth disease type 2B2
    Inheritance: AR Classification: SUPPORTIVE, NO_KNOWN Submitted by: Orphanet, ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (REVEL=0.183).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MED25NM_030973.4 linkc.764C>G p.Ala255Gly missense_variant Exon 7 of 18 ENST00000312865.10 NP_112235.2 Q71SY5-1
MED25NM_001378355.1 linkc.764C>G p.Ala255Gly missense_variant Exon 7 of 18 NP_001365284.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MED25ENST00000312865.10 linkc.764C>G p.Ala255Gly missense_variant Exon 7 of 18 1 NM_030973.4 ENSP00000326767.5 Q71SY5-1
MED25ENST00000538643.5 linkc.181-348C>G intron_variant Intron 2 of 12 1 ENSP00000437496.1 Q71SY5-6
MED25ENST00000595185.5 linkc.688+215C>G intron_variant Intron 6 of 6 1 ENSP00000470027.1 M0QYR4
MED25ENST00000593767.3 linkc.764C>G p.Ala255Gly missense_variant Exon 7 of 18 3 ENSP00000470692.3 M0QZQ2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
151962
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:
0.0000589
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000204
AC:
5
AN:
245624
AF XY:
0.0000299
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000452
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000166
AC:
24
AN:
1450008
Hom.:
0
Cov.:
30
AF XY:
0.0000235
AC XY:
17
AN XY:
721954
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33326
American (AMR)
AF:
0.00
AC:
0
AN:
44650
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26062
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39632
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86016
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51854
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5736
European-Non Finnish (NFE)
AF:
0.0000218
AC:
24
AN:
1102690
Other (OTH)
AF:
0.00
AC:
0
AN:
60042
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000263
AC:
4
AN:
151962
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74226
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41356
American (AMR)
AF:
0.00
AC:
0
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000589
AC:
4
AN:
67964
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00194621), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.00
Hom.:
0
Bravo
AF:
0.0000264
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000119

ClinVar

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

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Dec 21, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.764C>G (p.A255G) alteration is located in exon 7 (coding exon 7) of the MED25 gene. This alteration results from a C to G substitution at nucleotide position 764, causing the alanine (A) at amino acid position 255 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Charcot-Marie-Tooth disease type 2 Uncertain:1
Jun 13, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 255 of the MED25 protein (p.Ala255Gly). This variant is present in population databases (rs763825256, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with MED25-related conditions. ClinVar contains an entry for this variant (Variation ID: 543180). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.076
BayesDel_addAF
Benign
-0.33
T
BayesDel_noAF
Benign
-0.35
CADD
Benign
17
DANN
Uncertain
0.99
Eigen
Benign
-0.42
Eigen_PC
Benign
-0.36
FATHMM_MKL
Benign
0.069
N
M_CAP
Benign
0.024
T
PhyloP100
1.9
ClinPred
0.094
T
GERP RS
5.0
Varity_R
0.068
Mutation Taster
=92/8
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

Publications

Other links and lift over

dbSNP: rs763825256; hg19: chr19-50333420; API