X-71118829-C-T

Variant names:

• chrX-71118829-C-T
• NM_005120.3:c.75C>T

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_Moderate BP6_Moderate BP7 BS1 BS2

The NM_005120.3(MED12):​c.75C>T​(p.Tyr25Tyr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,097,094 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 2 hemizygotes 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: 20)
  • Exomes 𝑓: 0.0000055 (0 hom. 2 hem.)
• Consequence: MED12 NM_005120.3 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 1.41
• 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: Benign. The variant received -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.42).
• BP6: Variant X-71118829-C-T is Benign according to our data. Variant chrX-71118829-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 3711530.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=1.41 with no splicing effect.
• BS1: Variant frequency is greater than expected in population sas. GnomAdExome4 allele frequency = 0.00000547 (6/1097094) while in subpopulation SAS AF = 0.000074 (4/54036). AF 95% confidence interval is 0.0000253. There are 0 homozygotes in GnomAdExome4. There are 2 alleles in the male GnomAdExome4 subpopulation. Median coverage is 30. This position passed quality control check.
• BS2: High Hemizygotes in GnomAdExome4 at 2 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MED12	NM_005120.3	c.75C>T	p.Tyr25Tyr	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.75C>T	p.Tyr25Tyr	synonymous_variant	Exon 1 of 45	1	NM_005120.3	ENSP00000363193.3

Frequencies

GnomAD3 genomes Cov.: 20

GnomAD4 exome AF: 0.00000547 AC: 6 AN: 1097094 Hom.: 0 Cov.: 30 AF XY: 0.00000552 AC XY: 2 AN XY: 362574

African (AFR) AF: 0.00 AC: 0 AN: 26384

American (AMR) AF: 0.00 AC: 0 AN: 35185

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 30182

South Asian (SAS) AF: 0.0000740 AC: 4 AN: 54036

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40348

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4125

European-Non Finnish (NFE) AF: 0.00000238 AC: 2 AN: 841444

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

GnomAD4 genome Cov.: 20

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

FG syndrome Benign:1

Nov 11, 2024

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	-0.42
CADD	Benign	10
DANN	Uncertain	0.97
PhyloP100		1.4
PromoterAI		-0.016	Neutral

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-70338679;