chr16-28932047-T-A

Variant names:

• chr16-28932047-T-A
• rs745681190
• NM_001770.6:c.47T>A

Variant summary

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

The NM_001770.6(CD19):​c.47T>A​(p.Met16Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,824 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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. M16T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CD19 NM_001770.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.07
• Publications: 0 publications found

Genes affected

CD19 (HGNC:1633): (CD19 molecule) This gene encodes a member of the immunoglobulin gene superfamily. Expression of this cell surface protein is restricted to B cell lymphocytes. This protein is a reliable marker for pre-B cells but its expression diminishes during terminal B cell differentiation in antibody secreting plasma cells. The protein has two N-terminal extracellular Ig-like domains separated by a non-Ig-like domain, a hydrophobic transmembrane domain, and a large C-terminal cytoplasmic domain. This protein forms a complex with several membrane proteins including complement receptor type 2 (CD21) and tetraspanin (CD81) and this complex reduces the threshold for antigen-initiated B cell activation. Activation of this B-cell antigen receptor complex activates the phosphatidylinositol 3-kinase signalling pathway and the subsequent release of intracellular stores of calcium ions. This protein is a target of chimeric antigen receptor (CAR) T-cells used in the treatment of lymphoblastic leukemia. Mutations in this gene are associated with the disease common variable immunodeficiency 3 (CVID3) which results in a failure of B-cell differentiation and impaired secretion of immunoglobulins. CVID3 is characterized by hypogammaglobulinemia, an inability to mount an antibody response to antigen, and recurrent bacterial infections. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2020]

RABEP2 (HGNC:24817): (rabaptin, RAB GTPase binding effector protein 2) Predicted to enable GTPase activator activity and growth factor activity. Involved in regulation of cilium assembly. Located in cytosol; intracellular membrane-bounded organelle; and microtubule organizing center. [provided by Alliance of Genome Resources, Apr 2022]

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=0.10669428).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001770.6. 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
	CD19	NM_001770.6	MANE Select	c.47T>A	p.Met16Lys	missense	Exon 1 of 15	NP_001761.3
	CD19	NM_001178098.2		c.47T>A	p.Met16Lys	missense	Exon 1 of 15	NP_001171569.1	P15391-2
	CD19	NM_001385732.1		c.47T>A	p.Met16Lys	missense	Exon 1 of 14	NP_001372661.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CD19	ENST00000538922.8	TSL:5 MANE Select	c.47T>A	p.Met16Lys	missense	Exon 1 of 15	ENSP00000437940.2	P15391-1
	CD19	ENST00000324662.8	TSL:1	c.47T>A	p.Met16Lys	missense	Exon 1 of 15	ENSP00000313419.4	P15391-2
	RABEP2	ENST00000566762.1	TSL:4	c.-150+4217A>T		intron	N/A	ENSP00000454974.1	H3BNR8

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461824 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727222

⚠️ 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: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111954

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ 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.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.30	T
BayesDel_noAF	Benign	-0.66
CADD	Benign	1.2
DANN	Benign	0.73
DEOGEN2	Uncertain	0.51	D
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.012	N
LIST_S2	Benign	0.43	T
M_CAP	Benign	0.011	T
MetaRNN	Benign	0.11	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.84	L
PhyloP100		-1.1
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-1.3	N
REVEL	Benign	0.15
Sift	Benign	0.059	T
Sift4G	Benign	0.85	T
Polyphen		0.0	B
Vest4		0.22
MutPred		0.40		Gain of ubiquitination at M16 (P = 0.0238)
MVP		0.17
MPC		0.94
ClinPred		0.44	T
GERP RS		-11
PromoterAI		0.027	Neutral
Varity_R		0.27
gMVP		0.39

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: rs745681190; hg19: chr16-28943368;