rs760983756

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_018943.3(TUBA8):​c.132C>G​(p.Asn44Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. N44N) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

TUBA8
NM_018943.3 missense

Scores

1
18

Clinical Significance

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

Conservation

PhyloP100: -2.33

Publications

1 publications found
Variant links:
Genes affected
TUBA8 (HGNC:12410): (tubulin alpha 8) This gene encodes a member of the alpha tubulin protein family. Alpha tubulins are one of two core protein families (alpha and beta tubulins) that heterodimerize and assemble to form microtubules. Mutations in this gene are associated with polymicrogyria and optic nerve hypoplasia. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jul 2010]
TUBA8 Gene-Disease associations (from GenCC):
  • polymicrogyria with optic nerve hypoplasia
    Inheritance: Unknown, AR Classification: SUPPORTIVE, LIMITED, NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet, ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.02705741).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TUBA8NM_018943.3 linkc.132C>G p.Asn44Lys missense_variant Exon 2 of 5 ENST00000330423.8 NP_061816.1 Q9NY65-1
TUBA8NM_001193414.2 linkc.-67C>G 5_prime_UTR_variant Exon 2 of 5 NP_001180343.1 Q9NY65-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TUBA8ENST00000330423.8 linkc.132C>G p.Asn44Lys missense_variant Exon 2 of 5 1 NM_018943.3 ENSP00000333326.3 Q9NY65-1
ENSG00000288683ENST00000474897.6 linkn.*22C>G non_coding_transcript_exon_variant Exon 6 of 9 5 ENSP00000434235.2 E9PRC5
ENSG00000288683ENST00000474897.6 linkn.*22C>G 3_prime_UTR_variant Exon 6 of 9 5 ENSP00000434235.2 E9PRC5

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000517
AC:
13
AN:
251482
AF XY:
0.0000368
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000347
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.0000109
AC:
16
AN:
1461890
Hom.:
0
Cov.:
31
AF XY:
0.00000963
AC XY:
7
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000358
AC:
16
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
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:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.434
Heterozygous variant carriers
0
2
3
5
6
8
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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000412
AC:
5

ClinVar

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

Submissions by phenotype

not provided Uncertain:2
Oct 05, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 44 of the TUBA8 protein (p.Asn44Lys). This variant is present in population databases (rs760983756, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with TUBA8-related conditions. ClinVar contains an entry for this variant (Variation ID: 448844). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Jun 05, 2024
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is uninformative in assessment of its pathogenicity. (http://gnomad.broadinstitute.org) Polyphen and MutationTaster predict this amino acid change may be benign. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.44
T
BayesDel_noAF
Benign
-0.56
CADD
Benign
0.32
DANN
Benign
0.69
DEOGEN2
Benign
0.17
T;T
Eigen
Benign
-2.0
Eigen_PC
Benign
-2.1
FATHMM_MKL
Benign
0.067
N
LIST_S2
Benign
0.49
T;T
M_CAP
Benign
0.014
T
MetaRNN
Benign
0.027
T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.0
N;.
PhyloP100
-2.3
PrimateAI
Benign
0.34
T
PROVEAN
Benign
-0.90
N;N
REVEL
Benign
0.15
Sift
Uncertain
0.025
D;D
Sift4G
Benign
0.49
T;T
Polyphen
0.0
B;B
Vest4
0.20
MutPred
0.45
.;Gain of ubiquitination at N68 (P = 0.0066);
MVP
0.63
MPC
0.28
ClinPred
0.064
T
GERP RS
-10
Varity_R
0.074
gMVP
0.23
Mutation Taster
=97/3
polymorphism

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: rs760983756; hg19: chr22-18604374; COSMIC: COSV57813132; API