17-82781636-T-G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_005993.5(TBCD):​c.686T>G​(p.Leu229Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000929 in 1,613,774 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

TBCD
NM_005993.5 missense

Scores

9
8
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:2

Conservation

PhyloP100: 5.35

Publications

2 publications found
Variant links:
Genes affected
TBCD (HGNC:11581): (tubulin folding cofactor D) Cofactor D is one of four proteins (cofactors A, D, E, and C) involved in the pathway leading to correctly folded beta-tubulin from folding intermediates. Cofactors A and D are believed to play a role in capturing and stabilizing beta-tubulin intermediates in a quasi-native confirmation. Cofactor E binds to the cofactor D/beta-tubulin complex; interaction with cofactor C then causes the release of beta-tubulin polypeptides that are committed to the native state. [provided by RefSeq, Jul 2008]
TBCD Gene-Disease associations (from GenCC):
  • early-onset progressive diffuse brain atrophy-microcephaly-muscle weakness-optic atrophy syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.898

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TBCDNM_005993.5 linkc.686T>G p.Leu229Arg missense_variant Exon 7 of 39 ENST00000355528.9 NP_005984.3 Q9BTW9-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TBCDENST00000355528.9 linkc.686T>G p.Leu229Arg missense_variant Exon 7 of 39 1 NM_005993.5 ENSP00000347719.4 Q9BTW9-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152114
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000576
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
GnomAD2 exomes
AF:
0.0000201
AC:
5
AN:
249140
AF XY:
0.0000296
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000497
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461660
Hom.:
0
Cov.:
31
AF XY:
0.00000825
AC XY:
6
AN XY:
727120
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.000306
AC:
8
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53374
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111858
Other (OTH)
AF:
0.00
AC:
0
AN:
60368
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152114
Hom.:
0
Cov.:
31
AF XY:
0.0000404
AC XY:
3
AN XY:
74296
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41422
American (AMR)
AF:
0.00
AC:
0
AN:
15268
Ashkenazi Jewish (ASJ)
AF:
0.000576
AC:
2
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.558
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000508
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000248
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Early-onset progressive diffuse brain atrophy-microcephaly-muscle weakness-optic atrophy syndrome Pathogenic:1Uncertain:1
Nov 16, 2016
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Jun 27, 2019
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Jul 11, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TBCD c.686T>G (p.Leu229Arg) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 249140 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.686T>G has been reported in the literature in at least one compound heterozygous individual affected with Encephalopathy, Early Onset (e.g. Flex_2016). These data do not allow clear conclusions about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 27666370). ClinVar contains an entry for this variant (Variation ID: 268173). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.74
BayesDel_addAF
Pathogenic
0.38
D
BayesDel_noAF
Pathogenic
0.31
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Benign
0.33
T;.
Eigen
Uncertain
0.56
Eigen_PC
Uncertain
0.47
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.90
D;D
M_CAP
Pathogenic
0.47
D
MetaRNN
Pathogenic
0.90
D;D
MetaSVM
Uncertain
0.25
D
MutationAssessor
Pathogenic
3.6
H;.
PhyloP100
5.3
PrimateAI
Uncertain
0.57
T
PROVEAN
Pathogenic
-4.5
D;.
REVEL
Pathogenic
0.77
Sift
Uncertain
0.0010
D;.
Sift4G
Uncertain
0.0030
D;D
Polyphen
0.98
D;.
Vest4
0.96
MVP
0.86
MPC
1.2
ClinPred
0.95
D
GERP RS
5.3
Varity_R
0.77
gMVP
0.89
Mutation Taster
=15/85
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs778417127; hg19: chr17-80739512; API