13-36819427-C-G

Position:

• chr13-36819427-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000538.4(RFXAP):​c.70C>G​(p.Leu24Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000701 in 1,283,340 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000070 (0 hom.)
• Consequence: RFXAP NM_000538.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.601

Genes affected

RFXAP (HGNC:9988): (regulatory factor X associated 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 ankyrin-containing 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. Mutations in this gene have been linked to bare lymphocyte syndrome type II, complementation group D. Transcript variants utilizing different polyA signals have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0557729).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RFXAP	NM_000538.4	c.70C>G	p.Leu24Val	missense_variant	1/3	ENST00000255476.3	NP_000529.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RFXAP	ENST00000255476.3	c.70C>G	p.Leu24Val	missense_variant	1/3	1	NM_000538.4	ENSP00000255476	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000701 AC: 9 AN: 1283340 Hom.: 0 Cov.: 31 AF XY: 0.00000796 AC XY: 5 AN XY: 628394

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000266

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000189

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 22, 2023

The c.70C>G (p.L24V) alteration is located in exon 1 (coding exon 1) of the RFXAP gene. This alteration results from a C to G substitution at nucleotide position 70, causing the leucine (L) at amino acid position 24 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.060
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	10
DANN	Benign	0.66
DEOGEN2	Benign	0.022	T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.15	N
LIST_S2	Benign	0.38	T
M_CAP	Benign	0.043	D
MetaRNN	Benign	0.056	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.34	N
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-0.10	N
REVEL	Benign	0.044
Sift	Benign	0.26	T
Sift4G	Benign	0.38	T
Polyphen		0.0090	B
Vest4		0.069
MutPred		0.21		Gain of catalytic residue at L24 (P = 0.0067);
MVP		0.048
MPC		0.93
ClinPred		0.16	T
GERP RS		3.4
Varity_R		0.12
gMVP		0.040

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

Publications

LitVar

Other links and lift over

dbSNP: rs537036389; hg19: chr13-37393564;