rs199761611

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_030973.4(MED25):​c.1966C>A​(p.Pro656Thr) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000131 in 1,611,932 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 predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P656L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

MED25
NM_030973.4 missense, splice_region

Scores

1
10
8
Splicing: ADA: 0.8516
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:4

Conservation

PhyloP100: 1.96

Publications

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

BP4
Computational evidence support a benign effect (MetaRNN=0.21779403).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MED25NM_030973.4 linkc.1966C>A p.Pro656Thr missense_variant, splice_region_variant Exon 17 of 18 ENST00000312865.10 NP_112235.2 Q71SY5-1
MED25NM_001378355.1 linkc.1966C>A p.Pro656Thr missense_variant, splice_region_variant Exon 17 of 18 NP_001365284.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MED25ENST00000312865.10 linkc.1966C>A p.Pro656Thr missense_variant, splice_region_variant Exon 17 of 18 1 NM_030973.4 ENSP00000326767.5 Q71SY5-1

Frequencies

GnomAD3 genomes
AF:
0.000138
AC:
21
AN:
152208
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.000279
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000946
AC:
23
AN:
243146
AF XY:
0.000120
show subpopulations
Gnomad AFR exome
AF:
0.0000671
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:
0.000204
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000130
AC:
190
AN:
1459724
Hom.:
0
Cov.:
32
AF XY:
0.000138
AC XY:
100
AN XY:
726138
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.0000224
AC:
1
AN:
44696
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86198
European-Finnish (FIN)
AF:
0.0000191
AC:
1
AN:
52244
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5330
European-Non Finnish (NFE)
AF:
0.000166
AC:
184
AN:
1111706
Other (OTH)
AF:
0.0000498
AC:
3
AN:
60274
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.453
Heterozygous variant carriers
0
10
21
31
42
52
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000138
AC:
21
AN:
152208
Hom.:
0
Cov.:
32
AF XY:
0.000108
AC XY:
8
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000279
AC:
19
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
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

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:
0.000180
Hom.:
0
Bravo
AF:
0.000125
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000117
AC:
1
ExAC
AF:
0.000116
AC:
14
EpiCase
AF:
0.000164
EpiControl
AF:
0.000474

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Uncertain:2
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 12, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 656 of the MED25 protein (p.Pro656Thr). This variant is present in population databases (rs199761611, gnomAD 0.02%). This missense change has been observed in individual(s) with Charcot-Marie-Tooth disease (PMID: 26257172, 30039206). ClinVar contains an entry for this variant (Variation ID: 329887). 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: "Possibly Damaging"; 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. -

Tip-toe gait Pathogenic:1
Jan 11, 2022
Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In the molecular genetic analysis, the variant c.1966C>A p. (Pro656Thr) can be detected. The amino acid substitution is in a region responsible for binding of the retinoic acid receptor. The variant has been mentioned in the literature in connection with Charcot-Marie-Tooth disease [Gonzaga-Jauregui (2015) Cell Rep 12: 1169]. The authors describe a patient in whom the above variant in combination with a second heterozygous MED25 variant (c.1004C>T p.(Ala335Val)) was detected. However, the rating was the second variant Ala335Val was later withdrawn by the authors as a "causal pathogen" in another family with frequent occurrence of CMT [Leal (2018) Neurogenetics 19: 215]. Hereditary motor sensory neuropathy (HMSN), also known as Charcot-Marie-Tooth Disease (CMT), is the most commonly inherited peripheral polyneuropathy. It constitutes a group of inherited, progressive, motor and sensory peripheral nerve disorders with properties of demyelination, axonal degeneration, or both. It is classified by clinical characteristics, modes of inheritance, electrophysiologic features, metabolic defects, and specific gene markers. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed. -

Charcot-Marie-Tooth disease Uncertain:1
-
Molecular Genetics Laboratory, London Health Sciences Centre
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Dec 01, 2017
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.082
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.11
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.036
.;T;T;.;.;.
Eigen
Uncertain
0.44
Eigen_PC
Uncertain
0.46
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.91
D;D;D;D;.;.
M_CAP
Uncertain
0.18
D
MetaRNN
Benign
0.22
T;T;T;T;T;T
MetaSVM
Uncertain
0.22
D
MutationAssessor
Benign
1.3
.;.;L;.;.;.
PhyloP100
2.0
PrimateAI
Uncertain
0.67
T
PROVEAN
Benign
-0.39
.;.;N;N;.;.
REVEL
Uncertain
0.30
Sift
Pathogenic
0.0
.;.;D;D;.;.
Sift4G
Uncertain
0.024
D;D;D;D;D;.
Polyphen
1.0
.;.;D;.;.;.
Vest4
0.38
MVP
0.78
MPC
0.55
ClinPred
0.20
T
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.43
gMVP
0.53
Mutation Taster
=44/56
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.85
dbscSNV1_RF
Benign
0.62
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: rs199761611; hg19: chr19-50339483; API