Genetic Variant CTBS:p.Ala284Thr (chr1-84563364-C-T) – ACMG Classification: Uncertain_significance (0 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_004388.3(CTBS):c.850G>A(p.Ala284Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000022 in 1,593,962 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

CTBS
NM_004388.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.19

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.24770445).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CTBS	NM_004388.3 link	c.850G>A	p.Ala284Thr	missense_variant	Exon 6 of 7	ENST00000370630.6	NP_004379.1	Q01459Q8TC97
SPATA1	NM_001397487.1 link	c.1295-2497C>T		intron_variant	Intron 13 of 13	ENST00000699524.1	NP_001384416.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CTBS	ENST00000370630.6 link	c.850G>A	p.Ala284Thr	missense_variant	Exon 6 of 7	1	NM_004388.3	ENSP00000359664.4		Q01459
SPATA1	ENST00000699524.1 link	c.1295-2497C>T		intron_variant	Intron 13 of 13		NM_001397487.1	ENSP00000514414.1		A0A8V8TNU4

Frequencies

GnomAD3 genomes

AF:

0.0000855

AC:

AN:

152056

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000193

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000298

AC:

AN:

234608

Hom.:

AF XY:

0.0000156

AC XY:

AN XY:

127804

show subpopulations

Gnomad AFR exome

AF:

0.000208

Gnomad AMR exome

AF:

0.0000658

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:

0.0000185

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000153

AC:

AN:

1441906

Hom.:

Cov.:

AF XY:

0.0000139

AC XY:

AN XY:

717666

show subpopulations

Gnomad4 AFR exome

AF:

0.000186

Gnomad4 AMR exome

AF:

0.0000484

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:

0.0000127

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000855

AC:

AN:

152056

Hom.:

Cov.:

AF XY:

0.0000943

AC XY:

AN XY:

74256

show subpopulations

Gnomad4 AFR

AF:

0.000193

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:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000491

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000412

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 18, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.850G>A (p.A284T) alteration is located in exon 6 (coding exon 6) of the CTBS gene. This alteration results from a G to A substitution at nucleotide position 850, causing the alanine (A) at amino acid position 284 to be replaced by a threonine (T). 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

0.19

BayesDel_addAF

Benign

-0.32

BayesDel_noAF

Benign

-0.40

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.26

Eigen

Benign

0.18

Eigen_PC

Benign

0.12

FATHMM_MKL

Uncertain

0.93

LIST_S2

Benign

0.83

M_CAP

Benign

0.038

MetaRNN

Benign

0.25

MetaSVM

Benign

-1.1

MutationAssessor

Uncertain

2.5

PrimateAI

Benign

0.30

PROVEAN

Uncertain

-3.0

REVEL

Benign

0.21

Sift

Benign

0.043

Sift4G

Uncertain

0.054

Polyphen

0.91

Vest4

0.16

MVP

0.52

MPC

0.21

ClinPred

0.52

GERP RS

4.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.29

gMVP

0.80

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

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