NM_000246.4:c.21C>G

Variant names:

• chr16-10877351-C-G
• rs1251135434
• NM_000246.4:c.21C>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_000246.4(CIITA):​c.21C>G​(p.Arg7Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. R7R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CIITA NM_000246.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:2
• Conservation: PhyloP100: -0.590
• Publications: 0 publications found

Genes affected

CIITA (HGNC:7067): (class II major histocompatibility complex transactivator) This gene encodes a protein with an acidic transcriptional activation domain, 4 LRRs (leucine-rich repeats) and a GTP binding domain. The protein is located in the nucleus and acts as a positive regulator of class II major histocompatibility complex gene transcription, and is referred to as the "master control factor" for the expression of these genes. The protein also binds GTP and uses GTP binding to facilitate its own transport into the nucleus. Once in the nucleus it does not bind DNA but rather uses an intrinsic acetyltransferase (AT) activity to act in a coactivator-like fashion. Mutations in this gene have been associated with bare lymphocyte syndrome type II (also known as hereditary MHC class II deficiency or HLA class II-deficient combined immunodeficiency), increased susceptibility to rheumatoid arthritis, multiple sclerosis, and possibly myocardial infarction. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2013]

CIITA Gene-Disease associations (from GenCC):

• MHC class II deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Labcorp Genetics (formerly Invitae)

ENSG00000262151 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.75).
• BP6: Variant 16-10877351-C-G is Benign according to our data. Variant chr16-10877351-C-G is described in ClinVar as [Likely_benign]. Clinvar id is 2731404.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.59 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CIITA	NM_000246.4	c.21C>G	p.Arg7Arg	synonymous_variant	Exon 1 of 20	ENST00000324288.14	NP_000237.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CIITA	ENST00000324288.14	c.21C>G	p.Arg7Arg	synonymous_variant	Exon 1 of 20	1	NM_000246.4	ENSP00000316328.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

Submissions by phenotype

MHC class II deficiency Benign:2

Apr 30, 2025

Natera, Inc.

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jun 28, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
CADD	Benign	8.4
DANN	Benign	0.66
PhyloP100		-0.59
PromoterAI		0.17	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

dbSNP: rs1251135434; hg19: chr16-10971208;