6-32580855-T-C

Position:

• chr6-32580855-T-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_002124.4(HLA-DRB1):​c.654A>G​(p.Arg218Arg) variant causes a splice region, 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. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 27)
• Consequence: HLA-DRB1 NM_002124.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.0001993
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.12

Genes affected

HLA-DRB1 (HGNC:4948): (major histocompatibility complex, class II, DR beta 1) HLA-DRB1 belongs to the HLA class II beta chain paralogs. The class II molecule is a heterodimer consisting of an alpha (DRA) and a beta chain (DRB), both anchored in the membrane. It plays a central role in the immune system by presenting peptides derived from extracellular proteins. Class II molecules are expressed in antigen presenting cells. The beta chain is approximately 26-28 kDa. It is encoded by 6 exons. Exon one encodes the leader peptide; exons 2 and 3 encode the two extracellular domains; exon 4 encodes the transmembrane domain; and exon 5 encodes the cytoplasmic tail. Within the DR molecule the beta chain contains all the polymorphisms specifying the peptide binding specificities. Hundreds of DRB1 alleles have been described and some alleles have increased frequencies associated with certain diseases or conditions. For example, DRB1*1302 has been related to acute and chronic hepatitis B virus persistence. There are multiple pseudogenes of this gene. [provided by RefSeq, Jul 2020]

HLA-DRB1 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.73).
• BP7: Synonymous conserved (PhyloP=-1.12 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HLA-DRB1	NM_002124.4	c.654A>G	p.Arg218Arg	splice_region_variant, synonymous_variant	4/6	ENST00000360004.6	NP_002115.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HLA-DRB1	ENST00000360004.6	c.654A>G	p.Arg218Arg	splice_region_variant, synonymous_variant	4/6	6	NM_002124.4	ENSP00000353099.5

Frequencies

GnomAD3 genomes Cov.: 27

GnomAD4 exome Cov.: 70

GnomAD4 genome Cov.: 27

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.73
CADD	Benign	7.4
DANN	Benign	0.43

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00020
dbscSNV1_RF	Benign	0.016
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1136881; hg19: chr6-32548632;