rs128620188

Positions:

• chrX-101375242-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000061.3(BTK):​c.43C>T​(p.Gln15*) variant causes a stop gained change involving the alteration of a 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 Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: BTK NM_000061.3 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 8.28

Genes affected

BTK (HGNC:1133): (Bruton tyrosine kinase) The protein encoded by this gene plays a crucial role in B-cell development. Mutations in this gene cause X-linked agammaglobulinemia type 1, which is an immunodeficiency characterized by the failure to produce mature B lymphocytes, and associated with a failure of Ig heavy chain rearrangement. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Dec 2013]

BTK (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 72 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-101375242-G-A is Pathogenic according to our data. Variant chrX-101375242-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 11345.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-101375242-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BTK	NM_000061.3	c.43C>T	p.Gln15*	stop_gained	2/19	ENST00000308731.8	NP_000052.1
BTK	NM_001287344.2	c.145C>T	p.Gln49*	stop_gained	2/19		NP_001274273.1
BTK	NM_001287345.2	c.43C>T	p.Gln15*	stop_gained	3/17		NP_001274274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BTK	ENST00000308731.8	c.43C>T	p.Gln15*	stop_gained	2/19	1	NM_000061.3	ENSP00000308176.8

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

X-linked agammaglobulinemia Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 30, 2023	Variant summary: BTK c.43C>T (p.Gln15X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 183409 control chromosomes. c.43C>T has been reported in the literature in individuals affected with X-Linked Agammaglobulinemia (Conley_1994, Hagemann_1995, Turro_2020). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, no assertion criteria provided	literature only	OMIM	Oct 01, 1994	- -

X-linked agammaglobulinemia with growth hormone deficiency Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 19, 2022

This sequence change creates a premature translational stop signal (p.Gln15*) in the BTK gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BTK are known to be pathogenic (PMID: 15661032, 16862044, 19419768). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of agammaglobulinemia (PMID: 7849697, 32499645). ClinVar contains an entry for this variant (Variation ID: 11345). For these reasons, this variant has been classified as Pathogenic. -

Inherited Immunodeficiency Diseases Pathogenic:1

Likely pathogenic, criteria provided, single submitter

research

NIHR Bioresource Rare Diseases, University of Cambridge

Jan 01, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	37
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.97	D
Vest4		0.96
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7

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: rs128620188; hg19: chrX-100630230;