Genetic Variant CTBS:p.Arg349Gln (chr1-84555111-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_004388.3(CTBS):c.1046G>A(p.Arg349Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,613,710 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R349W) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

CTBS
NM_004388.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.77

Variant links:

Genes affected

CTBS (HGNC:2496): (chitobiase) Chitobiase is a lysosomal glycosidase involved in degradation of asparagine-linked oligosaccharides on glycoproteins (Aronson and Kuranda, 1989 [PubMed 2531691]).[supplied by OMIM, Nov 2010]

CTBS links:

SPATA1 (HGNC:14682): (spermatogenesis associated 1)

SPATA1 links:

ENSG00000285851 (HGNC:):

ENSG00000285851 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CTBS	NM_004388.3 link	c.1046G>A	p.Arg349Gln	missense_variant	Exon 7 of 7	ENST00000370630.6	NP_004379.1	Q01459Q8TC97
SPATA1	NM_001397487.1 link	c.1225-799C>T		intron_variant	Intron 12 of 13	ENST00000699524.1	NP_001384416.1
SPATA1	NM_001310156.2 link	c.*1-799C>T		intron_variant	Intron 13 of 13		NP_001297085.2	Q5VX52
SPATA1	XM_011542514.3 link	c.*1-799C>T		intron_variant	Intron 12 of 12		XP_011540816.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CTBS	ENST00000370630.6 link	c.1046G>A	p.Arg349Gln	missense_variant	Exon 7 of 7	1	NM_004388.3	ENSP00000359664.4		Q01459
SPATA1	ENST00000699524.1 link	c.1225-799C>T		intron_variant	Intron 12 of 13		NM_001397487.1	ENSP00000514414.1		A0A8V8TNU4

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152022

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251390

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135868

show subpopulations

Gnomad AFR exome

AF:

0.0000615

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:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461688

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727150

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000540

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152022

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74258

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000868

Hom.:

Bravo

AF:

0.0000264

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 14, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1046G>A (p.R349Q) alteration is located in exon 7 (coding exon 7) of the CTBS gene. This alteration results from a G to A substitution at nucleotide position 1046, causing the arginine (R) at amino acid position 349 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.36

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.27

Eigen

Uncertain

0.21

Eigen_PC

Benign

0.055

FATHMM_MKL

Uncertain

0.82

LIST_S2

Benign

0.81

M_CAP

Benign

0.020

MetaRNN

Uncertain

0.50

MetaSVM

Benign

-1.1

MutationAssessor

Pathogenic

3.0

PrimateAI

Benign

0.32

PROVEAN

Uncertain

-2.8

REVEL

Benign

0.20

Sift

Uncertain

0.018

Sift4G

Uncertain

0.048

Polyphen

1.0

Vest4

0.41

MutPred

0.63

Loss of MoRF binding (P = 0.0235);

MVP

0.57

MPC

0.36

ClinPred

0.94

GERP RS

0.30

Varity_R

0.10

gMVP

0.70

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.35

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.35

Position offset: -2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over