Genetic Variant TMEM200B:p.Ile255Thr (chr1-29121065-A-G) – 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_001003682.4(TMEM200B):c.764T>C(p.Ile255Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,694 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TMEM200B
NM_001003682.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.84

Variant links:

Genes affected

TMEM200B (HGNC:33785): (transmembrane protein 200B) Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

TMEM200B 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=0.088709146).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMEM200B	NM_001003682.4 link	c.764T>C	p.Ile255Thr	missense_variant	Exon 2 of 2	ENST00000521452.2	NP_001003682.1	Q69YZ2
TMEM200B	NM_001171868.2 link	c.764T>C	p.Ile255Thr	missense_variant	Exon 2 of 2		NP_001165339.1	Q69YZ2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMEM200B	ENST00000521452.2 link	c.764T>C	p.Ile255Thr	missense_variant	Exon 2 of 2	1	NM_001003682.4	ENSP00000428459.1		Q69YZ2
TMEM200B	ENST00000420504.2 link	c.764T>C	p.Ile255Thr	missense_variant	Exon 2 of 2	1		ENSP00000428544.1		Q69YZ2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152180

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461514

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727072

show subpopulations

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74366

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

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

Mar 08, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.764T>C (p.I255T) alteration is located in exon 2 (coding exon 1) of the TMEM200B gene. This alteration results from a T to C substitution at nucleotide position 764, causing the isoleucine (I) at amino acid position 255 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

0.28

BayesDel_addAF

Benign

-0.088

BayesDel_noAF

Benign

-0.36

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.0079

T;T

Eigen

Benign

-0.38

Eigen_PC

Benign

-0.24

FATHMM_MKL

Benign

0.41

LIST_S2

Benign

0.50

.;T

M_CAP

Benign

0.0017

MetaRNN

Benign

0.089

T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

0.34

N;N

PrimateAI

Pathogenic

0.86

PROVEAN

Benign

-0.52

N;N

REVEL

Benign

0.033

Sift

Uncertain

0.010

D;D

Sift4G

Benign

0.10

T;T

Polyphen

0.14

B;B

Vest4

0.22

MutPred

0.25

Loss of sheet (P = 0.0054);Loss of sheet (P = 0.0054);

MVP

0.055

MPC

1.4

ClinPred

0.14

GERP RS

2.5

Varity_R

0.12

gMVP

0.13

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