10-96192042-C-A

Variant summary

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

The NM_013314.4(BLNK):c.1302G>T(p.Leu434Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,461,442 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: BLNK NM_013314.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.461

Genes affected

BLNK (HGNC:14211): (B cell linker) This gene encodes a cytoplasmic linker or adaptor protein that plays a critical role in B cell development. This protein bridges B cell receptor-associated kinase activation with downstream signaling pathways, thereby affecting various biological functions. The phosphorylation of five tyrosine residues is necessary for this protein to nucleate distinct signaling effectors following B cell receptor activation. Mutations in this gene cause hypoglobulinemia and absent B cells, a disease in which the pro- to pre-B-cell transition is developmentally blocked. Deficiency in this protein has also been shown in some cases of pre-B acute lymphoblastic leukemia. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, May 2012]

ZNF518A (HGNC:29009): (zinc finger protein 518A) The protein encoded by this gene is a member of the krueppel C2H2-type zinc finger protein family. The encoded protein contains five zinc fingers and is likely a nuclear transcriptional regulator. Numerous transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, Aug 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.763

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BLNK	NM_013314.4	c.1302G>T	p.Leu434Phe	missense_variant	17/17	ENST00000224337.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BLNK	ENST00000224337.10	c.1302G>T	p.Leu434Phe	missense_variant	17/17	1	NM_013314.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251378 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135860

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1461442 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727022

Gnomad4 AFR exome AF: 0.00

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: 0.0000126

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.0000545

EpiControl AF: 0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Agammaglobulinemia 4, autosomal recessive Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 09, 2022

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 1355642). This variant has not been reported in the literature in individuals affected with BLNK-related conditions. This variant is present in population databases (rs782636828, gnomAD 0.002%). This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 434 of the BLNK protein (p.Leu434Phe). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.060
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;.;D;.
Eigen	Uncertain	0.30
Eigen_PC	Uncertain	0.27
FATHMM_MKL	Benign	0.66	D
LIST_S2	Pathogenic	0.98	D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.76	D;D;D;D
MetaSVM	Uncertain	-0.23	T
MutationAssessor	Pathogenic	3.5	H;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-3.4	D;D;.;D
REVEL	Uncertain	0.52
Sift	Pathogenic	0.0	D;D;.;D
Sift4G	Uncertain	0.0080	D;D;D;D
Polyphen		1.0	D;D;D;.
Vest4		0.80
MutPred		0.43		Loss of disorder (P = 0.1683);.;.;.;
MVP		0.86
MPC		1.1
ClinPred		0.98	D
GERP RS		3.1
Varity_R		0.61
gMVP		0.63

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.20		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.20		Position offset: -15

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

Publications

LitVar

Other links and lift over

dbSNP: rs782636828; hg19: chr10-97951798;