rs137853099

Positions:

• chr1-151344444-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001025603.2(RFX5):​c.446G>A​(p.Arg149Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: RFX5 NM_001025603.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 7.25

Genes affected

RFX5 (HGNC:9986): (regulatory factor X5) A lack of MHC-II expression results in a severe immunodeficiency syndrome called MHC-II deficiency, or the bare lymphocyte syndrome (BLS; MIM 209920). At least 4 complementation groups have been identified in B-cell lines established from patients with BLS. The molecular defects in complementation groups B, C, and D all lead to a deficiency in RFX, a nuclear protein complex that binds to the X box of MHC-II promoters. The lack of RFX binding activity in complementation group C results from mutations in the RFX5 gene encoding the 75-kD subunit of RFX (Steimle et al., 1995). RFX5 is the fifth member of the growing family of DNA-binding proteins sharing a novel and highly characteristic DNA-binding domain called the RFX motif. Multiple alternatively spliced transcript variants have been found but the full-length natures of only two have been determined. [provided by RefSeq, Jul 2008]

RFX5 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RFX5	NM_001025603.2	c.446G>A	p.Arg149Gln	missense_variant	7/11	ENST00000452671.7	NP_001020774.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RFX5	ENST00000452671.7	c.446G>A	p.Arg149Gln	missense_variant	7/11	1	NM_001025603.2	ENSP00000389130.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251442 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135898

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461890 Hom.: 0 Cov.: 33 AF XY: 0.00000550 AC XY: 4 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

MHC class II deficiency 5 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 2002

- -

MHC class II deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 27, 2018

This sequence change replaces arginine with glutamine at codon 149 of the RFX5 protein (p.Arg149Gln). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and glutamine. This variant is not present in population databases (ExAC no frequency). This variant has been reported in a family affected with bare lymphocyte syndrome (BLS) (PMID: 12368908). ClinVar contains an entry for this variant (Variation ID: 7648). Experimental studies using a patient-derived cell line have shown that this missense change abolishes RFX5 DNA binding activity and silences the expression of MHC class II genes (PMID: 12368908). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D;D;.;D;D;T;D;D
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.97	.;.;D;D;D;D;D;D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	3.5	M;M;.;M;.;.;.;.
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-3.8	D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;.;.;.;.
Polyphen		1.0	D;D;.;D;.;.;.;.
Vest4		0.88
MutPred		0.98		Loss of MoRF binding (P = 0.0329);Loss of MoRF binding (P = 0.0329);.;Loss of MoRF binding (P = 0.0329);Loss of MoRF binding (P = 0.0329);Loss of MoRF binding (P = 0.0329);Loss of MoRF binding (P = 0.0329);Loss of MoRF binding (P = 0.0329);
MVP		0.95
MPC		0.67
ClinPred		0.99	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.90
gMVP		0.72

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs137853099; hg19: chr1-151316920; COSMIC: COSV100923880; COSMIC: COSV100923880;