X-71118788-C-T

Variant names:

• chrX-71118788-C-T
• NM_005120.3:c.34C>T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_005120.3(MED12):​c.34C>T​(p.Arg12Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000911 in 1,097,344 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 20)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: MED12 NM_005120.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.57
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• FG syndrome 1

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
• MED12-related intellectual disability syndrome

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• X-linked intellectual disability with marfanoid habitus

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
• blepharophimosis - intellectual disability syndrome, MKB type

  Inheritance: XL Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• cholestasis-pigmentary retinopathy-cleft palate syndrome

  Inheritance: XL Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.8

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MED12	NM_005120.3	c.34C>T	p.Arg12Trp	missense_variant	Exon 1 of 45	ENST00000374080.8	NP_005111.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MED12	ENST00000374080.8	c.34C>T	p.Arg12Trp	missense_variant	Exon 1 of 45	1	NM_005120.3	ENSP00000363193.3

Frequencies

GnomAD3 genomes Cov.: 20

GnomAD4 exome AF: 9.11e-7 AC: 1 AN: 1097344 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 362886

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 26383

American (AMR) AF: 0.00 AC: 0 AN: 35187

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19369

East Asian (EAS) AF: 0.00 AC: 0 AN: 30178

South Asian (SAS) AF: 0.00 AC: 0 AN: 54059

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40284

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4117

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 841746

Other (OTH) AF: 0.00 AC: 0 AN: 46021

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 20

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Sep 20, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.78	.;D
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.80	D;D
MetaSVM	Uncertain	-0.099	T
MutationAssessor	Uncertain	2.2	M;M
PhyloP100		2.6
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-5.0	D;D
REVEL	Uncertain	0.53
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.51
MutPred		0.59		Loss of disorder (P = 2e-04);Loss of disorder (P = 2e-04);
MVP		0.79
MPC		2.1
ClinPred		1.0	D
GERP RS		4.1
PromoterAI		-0.026	Neutral
Varity_R		0.85
gMVP		0.89
Mutation Taster		=78/22	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

hg19: chrX-70338638; COSMIC: COSV100380619; COSMIC: COSV100380619;