NM_005120.3:c.15G>C

Variant names:

• chrX-71118769-G-C
• NM_005120.3:c.15G>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6_Moderate

The NM_005120.3(MED12):​c.15G>C​(p.Gly5Gly) variant causes a synonymous change. The variant allele was found at a frequency of 0.000000912 in 1,096,520 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 21)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: MED12 NM_005120.3 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 3.58
• 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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.44).
• BP6: Variant X-71118769-G-C is Benign according to our data. Variant chrX-71118769-G-C is described in ClinVar as [Likely_benign]. Clinvar id is 2804388.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MED12	NM_005120.3	c.15G>C	p.Gly5Gly	synonymous_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.15G>C	p.Gly5Gly	synonymous_variant	Exon 1 of 45	1	NM_005120.3	ENSP00000363193.3

Frequencies

GnomAD3 genomes Cov.: 21

GnomAD4 exome AF: 9.12e-7 AC: 1 AN: 1096520 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 362246

⚠️ 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: 26376

American (AMR) AF: 0.00 AC: 0 AN: 35157

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19341

East Asian (EAS) AF: 0.00 AC: 0 AN: 30151

South Asian (SAS) AF: 0.00 AC: 0 AN: 53883

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40171

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4088

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 841374

Other (OTH) AF: 0.00 AC: 0 AN: 45979

⚠️ 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.: 21

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

FG syndrome Benign:1

Jul 31, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.44
CADD	Benign	14
DANN	Benign	0.92
PhyloP100		3.6
PromoterAI		0.0038	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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-70338619;