X-101349933-G-C

Variant names:

• chrX-101349933-G-C
• rs1926219727
• NM_000061.3:c.1932C>G

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The NM_000061.3(BTK):​c.1932C>G​(p.Phe644Leu) variant causes a missense change. 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F644S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: BTK NM_000061.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.29

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]

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PM1: In a domain Protein kinase (size 253) in uniprot entity BTK_HUMAN there are 43 pathogenic changes around while only 1 benign (98%) in NM_000061.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP2: Missense variant in the BTK gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 90 curated pathogenic missense variants (we use a threshold of 10). The gene has 26 curated benign missense variants. Gene score misZ: 4.0394 (above the threshold of 3.09). GenCC associations: The gene is linked to short stature due to isolated growth hormone deficiency with X-linked hypogammaglobulinemia, Bruton-type agammaglobulinemia, isolated growth hormone deficiency type III.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983
• PP5: Variant X-101349933-G-C is Pathogenic according to our data. Variant chrX-101349933-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1047473.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BTK	NM_000061.3	c.1932C>G	p.Phe644Leu	missense_variant	Exon 19 of 19	ENST00000308731.8	NP_000052.1
BTK	NM_001287344.2	c.2034C>G	p.Phe678Leu	missense_variant	Exon 19 of 19		NP_001274273.1
BTK	NM_001287345.2	c.1404C>G	p.Phe468Leu	missense_variant	Exon 17 of 17		NP_001274274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BTK	ENST00000308731.8	c.1932C>G	p.Phe644Leu	missense_variant	Exon 19 of 19	1	NM_000061.3	ENSP00000308176.8

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 22

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

X-linked agammaglobulinemia with growth hormone deficiency Pathogenic:1

Oct 24, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 644 of the BTK protein (p.Phe644Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with X-linked agammaglobulinaemia (PMID: 27535475, 29709555). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt BTK protein function. This variant disrupts the p.Phe644 amino acid residue in BTK. Other variant(s) that disrupt this residue have been observed in individuals with BTK-related conditions (PMID: 8695804, 19419768, 32552675), which suggests that this may be a clinically significant amino acid residue. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	.;.;D
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.87	D;T;T
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Uncertain	0.21	D
MutationAssessor	Pathogenic	3.6	.;.;H
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-4.9	D;.;D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;.;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;.;D
Vest4		0.89
MutPred		0.94		.;.;Gain of loop (P = 0.1069);
MVP		1.0
MPC		2.5
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.96
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1926219727; hg19: chrX-100604921;