22-18121480-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_001193414.2(TUBA8):​c.-194G>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

TUBA8
NM_001193414.2 5_prime_UTR_premature_start_codon_gain

Scores

12
6
Splicing: ADA: 0.9801
2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 10.0

Publications

3 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: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001193414.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TUBA8
NM_018943.3
MANE Select
c.5G>Tp.Arg2Leu
missense splice_region
Exon 2 of 5NP_061816.1Q9NY65-1
TUBA8
NM_001193414.2
c.-194G>T
5_prime_UTR_premature_start_codon_gain
Exon 2 of 5NP_001180343.1Q9NY65-2
TUBA8
NM_001193414.2
c.-194G>T
splice_region
Exon 2 of 5NP_001180343.1Q9NY65-2

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TUBA8
ENST00000416740.2
TSL:1
c.-194G>T
5_prime_UTR_premature_start_codon_gain
Exon 2 of 5ENSP00000412646.2Q9NY65-2
TUBA8
ENST00000330423.8
TSL:1 MANE Select
c.5G>Tp.Arg2Leu
missense splice_region
Exon 2 of 5ENSP00000333326.3Q9NY65-1
TUBA8
ENST00000416740.2
TSL:1
c.-194G>T
splice_region
Exon 2 of 5ENSP00000412646.2Q9NY65-2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152160
Hom.:
0
Cov.:
32
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:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
251336
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
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:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461578
Hom.:
0
Cov.:
30
AF XY:
0.00000413
AC XY:
3
AN XY:
727092
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000101
AC:
4
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111726
Other (OTH)
AF:
0.00
AC:
0
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.00000657
AC:
1
AN:
152160
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41430
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.35
CADD
Pathogenic
32
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.70
D
Eigen
Pathogenic
0.89
Eigen_PC
Pathogenic
0.83
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
1.0
D
M_CAP
Uncertain
0.17
D
MetaRNN
Pathogenic
0.80
D
MetaSVM
Uncertain
0.63
D
MutationAssessor
Pathogenic
3.7
H
PhyloP100
10
PrimateAI
Pathogenic
0.89
D
PROVEAN
Uncertain
-3.5
D
REVEL
Pathogenic
0.83
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.0020
D
Polyphen
0.27
B
Vest4
0.93
MutPred
0.70
Gain of sheet (P = 0.0221)
MVP
0.94
MPC
0.90
ClinPred
1.0
D
GERP RS
5.1
Varity_R
0.72
gMVP
0.90
Mutation Taster
=223/77
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
0.98
dbscSNV1_RF
Pathogenic
0.83
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: rs761087286; hg19: chr22-18604247; API