X-71124276-G-A

Position:

• chrX-71124276-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2 PP2 PP3 PP5_Very_Strong

The NM_005120.3(MED12):​c.1862G>A​(p.Arg621Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: MED12 NM_005120.3 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 O:1
• Conservation: PhyloP100: 9.60

Genes affected

MED12 (HGNC:11957): (mediator complex subunit 12) The initiation of transcription is controlled in part by a large protein assembly known as the preinitiation complex. A component of this preinitiation complex is a 1.2 MDa protein aggregate called Mediator. This Mediator component binds with a CDK8 subcomplex which contains the protein encoded by this gene, mediator complex subunit 12 (MED12), along with MED13, CDK8 kinase, and cyclin C. The CDK8 subcomplex modulates Mediator-polymerase II interactions and thereby regulates transcription initiation and reinitation rates. The MED12 protein is essential for activating CDK8 kinase. Defects in this gene cause X-linked Opitz-Kaveggia syndrome, also known as FG syndrome, and Lujan-Fryns syndrome. [provided by RefSeq, Aug 2009]

MED12 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MED12. . Gene score misZ 6.5797 (greater than the threshold 3.09). GenCC has associacion of gene with MED12-related intellectual disability syndrome, X-linked intellectual disability with marfanoid habitus, blepharophimosis - intellectual disability syndrome, MKB type, FG syndrome 1, cholestasis-pigmentary retinopathy-cleft palate syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.752
• PP5: Variant X-71124276-G-A is Pathogenic according to our data. Variant chrX-71124276-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 225253.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MED12	NM_005120.3	c.1862G>A	p.Arg621Gln	missense_variant	13/45	ENST00000374080.8	NP_005111.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MED12	ENST00000374080.8	c.1862G>A	p.Arg621Gln	missense_variant	13/45	1	NM_005120.3	ENSP00000363193.3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

FG syndrome 1 Pathogenic:1 Other:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Department of Medical Genetics, Oslo University Hospital	Apr 15, 2016	Hemizygosity for c.1862G>A was detected in the proband and an affected fetus. The variant was inherited from the unaffected mother were the mutated allele was completely inactivated in blood (100:0 skewed X chromosome inactivation). The variant was found to be de novo in the mother. The variant predicts the amino acid substitution p.Arg621Gln. The Arg621 is conserved across species from human to xenopus as well as in the paralog MED12L. The variant has not been reported in ExAc (Oct2015). -
not provided, no classification provided	literature only	GeneReviews	-	Reported in male sibs with nonspecific intellectual disability -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jun 03, 2024

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 27286923, 36271811) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Pathogenic	35
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.067	T;.;T
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Pathogenic	0.39	D
MetaRNN	Pathogenic	0.75	D;D;D
MetaSVM	Uncertain	-0.071	T
MutationAssessor	Uncertain	2.8	.;M;M
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-3.4	.;D;D
REVEL	Uncertain	0.52
Sift	Uncertain	0.0040	.;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;D
Vest4		0.63
MutPred		0.57		.;Gain of relative solvent accessibility (P = 0.09);Gain of relative solvent accessibility (P = 0.09);
MVP		0.94
MPC		2.2
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.76
gMVP		0.77

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.67		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.67		Position offset: 3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1057519381; hg19: chrX-70344126; COSMIC: COSV61344559; COSMIC: COSV61344559;