rs752168879

chr19-19197256-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_003721.4(RFXANK):c.337+5G>A variant causes a splice donor 5th base, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000031 in 1,612,358 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000072 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: RFXANK NM_003721.4 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9926
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.73

Genes affected

RFXANK (HGNC:9987): (regulatory factor X associated ankyrin containing protein) Major histocompatibility (MHC) class II molecules are transmembrane proteins that have a central role in development and control of the immune system. The protein encoded by this gene, along with regulatory factor X-associated protein and regulatory factor-5, forms a complex that binds to the X box motif of certain MHC class II gene promoters and activates their transcription. Once bound to the promoter, this complex associates with the non-DNA-binding factor MHC class II transactivator, which controls the cell type specificity and inducibility of MHC class II gene expression. This protein contains ankyrin repeats involved in protein-protein interactions. Mutations in this gene have been linked to bare lymphocyte syndrome type II, complementation group B. Multiple alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Jul 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RFXANK	NM_003721.4	c.337+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000303088.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RFXANK	ENST00000303088.9	c.337+5G>A		splice_donor_5th_base_variant, intron_variant		1	NM_003721.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000723 AC: 11 AN: 152198 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000169

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000200 AC: 5 AN: 250480 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135524

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000353

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000267 AC: 39 AN: 1460160 Hom.: 0 Cov.: 32 AF XY: 0.0000275 AC XY: 20 AN XY: 726398

Gnomad4 AFR exome AF: 0.0000598

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000297

Gnomad4 OTH exome AF: 0.0000664

GnomAD4 genome AF: 0.0000723 AC: 11 AN: 152198 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74346

Gnomad4 AFR AF: 0.000169

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000130 Hom.: 0

Bravo AF: 0.0000416

EpiCase AF: 0.0000545

EpiControl AF: 0.000237

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

MHC class II deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 08, 2022

This sequence change falls in intron 5 of the RFXANK gene. It does not directly change the encoded amino acid sequence of the RFXANK protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs752168879, gnomAD 0.008%). This variant has not been reported in the literature in individuals affected with RFXANK-related conditions. ClinVar contains an entry for this variant (Variation ID: 583327). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Jul 14, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.37
Cadd	Benign	21
Dann	Benign	0.90

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.76
SpliceAI score (max)		0.64		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.64		Position offset: -5

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

Publications

LitVar

Other links and lift over

dbSNP: rs752168879; hg19: chr19-19308065;