rs878855132

Variant names:

• chr19-49835932-T-G
• rs878855132
• NM_030973.4:c.1952T>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_030973.4(MED25):​c.1952T>G​(p.Leu651Arg) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. L651F) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MED25 NM_030973.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.01
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MED25	NM_030973.4	c.1952T>G	p.Leu651Arg	missense_variant	Exon 16 of 18	ENST00000312865.10	NP_112235.2
MED25	NM_001378355.1	c.1952T>G	p.Leu651Arg	missense_variant	Exon 16 of 18		NP_001365284.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MED25	ENST00000312865.10	c.1952T>G	p.Leu651Arg	missense_variant	Exon 16 of 18	1	NM_030973.4	ENSP00000326767.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000409 AC: 1 AN: 244338 AF XY: 0.00000747

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: 0.00000917

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Uncertain:1

Nov 15, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with MED25-related disease. ClinVar contains an entry for this variant (Variation ID: 241614). This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with arginine at codon 651 of the MED25 protein (p.Leu651Arg). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and arginine. Algorithms developed to predict the effect of missense changes on protein structure and function 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.064	.;T;T;.;.;.
Eigen	Benign	-0.058
Eigen_PC	Benign	0.023
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D;D;D;.;.
M_CAP	Uncertain	0.096	D
MetaRNN	Uncertain	0.46	T;T;T;T;T;T
MetaSVM	Benign	-0.97	T
MutationAssessor	Benign	1.7	.;.;L;.;.;.
PhyloP100		6.0
PrimateAI	Pathogenic	0.85	D
PROVEAN	Benign	0.32	.;.;N;N;.;.
REVEL	Uncertain	0.58
Sift	Pathogenic	0.0	.;.;D;D;.;.
Sift4G	Benign	0.35	T;T;T;T;T;.
Polyphen		1.0	.;.;D;.;.;.
Vest4		0.72
MutPred		0.34		.;.;Gain of solvent accessibility (P = 0.0171);.;.;.;
MVP		0.80
MPC		0.64
ClinPred		0.85	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.61
gMVP		0.73
Mutation Taster		=55/45	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

Other links and lift over

dbSNP: rs878855132; hg19: chr19-50339189;