NM_004830.4:c.479T>A

Variant names:

• chr6-131621897-A-T
• rs786205583
• NM_004830.4:c.479T>A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PM5 PP2 PP3_Moderate

The NM_004830.4(MED23):​c.479T>A​(p.Leu160His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,455,140 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L160P) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MED23 NM_004830.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.32
• Publications: 0 publications found

Genes affected

MED23 (HGNC:2372): (mediator complex subunit 23) The activation of gene transcription is a multistep process that is triggered by factors that recognize transcriptional enhancer sites in DNA. These factors work with co-activators to direct transcriptional initiation by the RNA polymerase II apparatus. The protein encoded by this gene is a subunit of the CRSP (cofactor required for SP1 activation) complex, which, along with TFIID, is required for efficient activation by SP1. This protein is also a component of other multisubunit complexes e.g. thyroid hormone receptor-(TR-) associated proteins which interact with TR and facilitate TR function on DNA templates in conjunction with initiation factors and cofactors. This protein also acts as a metastasis suppressor. Several alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Jul 2012]

MED23 Gene-Disease associations (from GenCC):

• intellectual disability, autosomal recessive 18

  Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• syndromic intellectual disability

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• autosomal recessive non-syndromic intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-131621897-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 191215.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 9 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Gene score misZ: 4.7291 (above the threshold of 3.09). Trascript score misZ: 5.9944 (above the threshold of 3.09). GenCC associations: The gene is linked to intellectual disability, autosomal recessive 18, syndromic intellectual disability, autosomal recessive non-syndromic intellectual disability.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.88

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MED23	NM_004830.4	c.479T>A	p.Leu160His	missense_variant	Exon 6 of 29	ENST00000368068.8	NP_004821.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MED23	ENST00000368068.8	c.479T>A	p.Leu160His	missense_variant	Exon 6 of 29	1	NM_004830.4	ENSP00000357047.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1455140 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 723736

⚠️ 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: 33216

American (AMR) AF: 0.0000229 AC: 1 AN: 43714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25926

East Asian (EAS) AF: 0.00 AC: 0 AN: 39564

South Asian (SAS) AF: 0.00 AC: 0 AN: 84718

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53342

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5738

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1108808

Other (OTH) AF: 0.00 AC: 0 AN: 60114

⚠️ 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.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	28
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.74	.;D;.;.;.;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.88	D;D;D;D;D;D
MetaSVM	Uncertain	0.25	D
MutationAssessor	Benign	0.81	L;L;L;.;L;L
PhyloP100		9.3
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-3.9	D;D;D;D;D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D;D;D;D;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D;D
Polyphen		1.0	D;D;.;.;D;.
Vest4		0.93
MutPred		0.62		Gain of disorder (P = 0.1405);Gain of disorder (P = 0.1405);Gain of disorder (P = 0.1405);Gain of disorder (P = 0.1405);Gain of disorder (P = 0.1405);Gain of disorder (P = 0.1405);
MVP		0.81
MPC		0.72
ClinPred		0.99	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.90
gMVP		0.85
Mutation Taster		=9/91	disease causing

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: rs786205583; hg19: chr6-131943037;