chr19-49836233-C-T

Variant summary

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

The NM_030973.4(MED25):​c.1973C>T​(p.Thr658Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000447 in 1,612,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T658P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000047 ( 0 hom. )

Consequence

MED25
NM_030973.4 missense

Scores

1
3
12

Clinical Significance

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

Conservation

PhyloP100: 1.29

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 (MetaRNN=0.119246244).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MED25NM_030973.4 linkc.1973C>T p.Thr658Ile missense_variant Exon 17 of 18 ENST00000312865.10 NP_112235.2
MED25NM_001378355.1 linkc.1973C>T p.Thr658Ile missense_variant Exon 17 of 18 NP_001365284.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MED25ENST00000312865.10 linkc.1973C>T p.Thr658Ile missense_variant Exon 17 of 18 1 NM_030973.4 ENSP00000326767.5

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152184
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000206
AC:
5
AN:
243076
AF XY:
0.0000150
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:
0.0000463
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000473
AC:
69
AN:
1460014
Hom.:
0
Cov.:
32
AF XY:
0.0000330
AC XY:
24
AN XY:
726280
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33466
American (AMR)
AF:
0.00
AC:
0
AN:
44698
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86226
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52262
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5430
European-Non Finnish (NFE)
AF:
0.0000612
AC:
68
AN:
1111820
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60290
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
Heterozygous variant carriers
0
4
8
12
16
20
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000197
AC:
3
AN:
152184
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74352
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68006
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.000174
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000825
AC:
1
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

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
Jun 18, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1973C>T (p.T658I) alteration is located in exon 17 (coding exon 17) of the MED25 gene. This alteration results from a C to T substitution at nucleotide position 1973, causing the threonine (T) at amino acid position 658 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Charcot-Marie-Tooth disease type 2 Uncertain:1
Jun 20, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 658 of the MED25 protein (p.Thr658Ile). This variant is present in population databases (rs768469811, gnomAD 0.004%). 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: 543175). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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
0.25
BayesDel_addAF
Benign
-0.19
T
BayesDel_noAF
Benign
-0.40
CADD
Benign
20
DANN
Uncertain
1.0
DEOGEN2
Benign
0.0
.;T;T;.;.;.
Eigen
Benign
-0.38
Eigen_PC
Benign
-0.26
LIST_S2
Uncertain
0.88
D;D;D;D;.;.
M_CAP
Benign
0.047
D
MetaRNN
Benign
0.12
T;T;T;T;T;T
MetaSVM
Benign
-0.77
T
MutationAssessor
Benign
0.0
.;.;N;.;.;.
PhyloP100
1.3
PrimateAI
Uncertain
0.71
T
PROVEAN
Benign
0.0
.;.;N;N;.;.
Sift
Pathogenic
0.0
.;.;D;D;.;.
Sift4G
Benign
0.19
T;T;T;D;T;.
Vest4
0.33
ClinPred
0.13
T
GERP RS
2.7
Varity_R
0.19
gMVP
0.30
Mutation Taster
=90/10
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.15
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: rs768469811; hg19: chr19-50339490; API