chr16-28932385-C-A

Position:

• chr16-28932385-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001770.6(CD19):​c.128C>A​(p.Ser43Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CD19 NM_001770.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.0310

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

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-28932385-C-A is Pathogenic according to our data. Variant chr16-28932385-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 1401146.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CD19	NM_001770.6	c.128C>A	p.Ser43Ter	stop_gained	2/15	ENST00000538922.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CD19	ENST00000538922.8	c.128C>A	p.Ser43Ter	stop_gained	2/15	5	NM_001770.6	P3
CD19	ENST00000324662.8	c.128C>A	p.Ser43Ter	stop_gained	2/15	1		A2
RABEP2	ENST00000566762.1	c.-150+3879G>T		intron_variant		4
CD19	ENST00000565089.5	n.164C>A		non_coding_transcript_exon_variant	2/13	2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 38

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 29, 2021

This sequence change creates a premature translational stop signal (p.Ser43*) in the CD19 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CD19 are known to be pathogenic (PMID: 16672701). This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with CD19-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	26
DANN	Uncertain	0.98
Eigen	Benign	0.038
Eigen_PC	Benign	-0.28
FATHMM_MKL	Benign	0.029	N
MutationTaster	Benign	1.0	A;A;A
Vest4		0.80
GERP RS		2.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-28943706;