13-36819401-C-A

Variant names:

• chr13-36819401-C-A
• rs1344939848
• NM_000538.4:c.44C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000538.4(RFXAP):​c.44C>A​(p.Ala15Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000866 in 1,154,674 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A15V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 8.7e-7 (0 hom.)
• Consequence: RFXAP NM_000538.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.596
• Publications: 0 publications found

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]

RFXAP Gene-Disease associations (from GenCC):

• MHC class II deficiency

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

ENSG00000309469 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1403296).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000538.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RFXAP	NM_000538.4	MANE Select	c.44C>A	p.Ala15Asp	missense	Exon 1 of 3	NP_000529.1	O00287

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RFXAP	ENST00000255476.3	TSL:1 MANE Select	c.44C>A	p.Ala15Asp	missense	Exon 1 of 3	ENSP00000255476.3	O00287
	ENSG00000309469	ENST00000841309.1		n.122+176G>T		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 8.66e-7 AC: 1 AN: 1154674 Hom.: 0 Cov.: 31 AF XY: 0.00000181 AC XY: 1 AN XY: 553876

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 23274

American (AMR) AF: 0.00 AC: 0 AN: 8812

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 15190

East Asian (EAS) AF: 0.00 AC: 0 AN: 27180

South Asian (SAS) AF: 0.00 AC: 0 AN: 30796

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 32970

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3358

European-Non Finnish (NFE) AF: 0.00000104 AC: 1 AN: 965992

Other (OTH) AF: 0.00 AC: 0 AN: 47102

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Uncertain	0.020	T
BayesDel_noAF	Benign	-0.21
CADD	Benign	18
DANN	Uncertain	0.99
DEOGEN2	Benign	0.034	T
Eigen	Benign	-0.59
Eigen_PC	Benign	-0.65
FATHMM_MKL	Benign	0.21	N
LIST_S2	Benign	0.42	T
M_CAP	Uncertain	0.10	D
MetaRNN	Benign	0.14	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.90	L
PhyloP100		0.60
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-1.5	N
REVEL	Benign	0.079
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.022	D
Polyphen		0.57	P
Vest4		0.31
MutPred		0.22		Gain of catalytic residue at A15 (P = 0.0023)
MVP		0.10
MPC		2.3
ClinPred		0.59	D
GERP RS		3.8
PromoterAI		-0.066	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.32
gMVP		0.24
Mutation Taster		=92/8	polymorphism

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: rs1344939848; hg19: chr13-37393538;