chr8-63085844-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BS1_Supporting

The NM_000370.3(TTPA):​c.178G>A​(p.Asp60Asn) variant causes a missense change. The variant allele was found at a frequency of 0.000732 in 1,536,736 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00043 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00076 ( 1 hom. )

Consequence

TTPA
NM_000370.3 missense

Scores

2
10
6

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:8

Conservation

PhyloP100: 5.00

Publications

3 publications found
Variant links:
Genes affected
TTPA (HGNC:12404): (alpha tocopherol transfer protein) This gene encodes a soluble protein that binds alpha-trocopherol, a form of vitamin E, with high selectivity and affinity. This protein plays an important role in regulating vitamin E levels in the body by transporting vitamin E between membrane vesicles and facilitating the secretion of vitamin E from hepatocytes to circulating lipoproteins. Mutations in this gene cause hereditary vitamin E deficiency (ataxia with vitamin E deficiency, AVED) and retinitis pigmentosa. [provided by RefSeq, Nov 2009]
TTPA Gene-Disease associations (from GenCC):
  • familial isolated deficiency of vitamin E
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Myriad Women’s Health, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_000370.3
BS1
Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.000765 (1059/1384452) while in subpopulation NFE AF = 0.000922 (993/1077568). AF 95% confidence interval is 0.000874. There are 1 homozygotes in GnomAdExome4. There are 491 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000370.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTPA
NM_000370.3
MANE Select
c.178G>Ap.Asp60Asn
missense
Exon 1 of 5NP_000361.1P49638
TTPA
NM_001413418.1
c.178G>Ap.Asp60Asn
missense
Exon 1 of 6NP_001400347.1
TTPA
NM_001413416.1
c.178G>Ap.Asp60Asn
missense
Exon 1 of 5NP_001400345.1

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTPA
ENST00000260116.5
TSL:1 MANE Select
c.178G>Ap.Asp60Asn
missense
Exon 1 of 5ENSP00000260116.4P49638
TTPA
ENST00000878696.1
c.178G>Ap.Asp60Asn
missense
Exon 1 of 6ENSP00000548755.1
TTPA
ENST00000878697.1
c.178G>Ap.Asp60Asn
missense
Exon 1 of 4ENSP00000548756.1

Frequencies

GnomAD3 genomes
AF:
0.000434
AC:
66
AN:
152174
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000169
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.000853
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000385
AC:
50
AN:
129878
AF XY:
0.000323
show subpopulations
Gnomad AFR exome
AF:
0.000680
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:
0.000865
Gnomad OTH exome
AF:
0.000752
GnomAD4 exome
AF:
0.000765
AC:
1059
AN:
1384452
Hom.:
1
Cov.:
31
AF XY:
0.000719
AC XY:
491
AN XY:
683322
show subpopulations
African (AFR)
AF:
0.000225
AC:
7
AN:
31080
American (AMR)
AF:
0.00
AC:
0
AN:
35576
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25076
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35524
South Asian (SAS)
AF:
0.0000254
AC:
2
AN:
78864
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
38614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4494
European-Non Finnish (NFE)
AF:
0.000922
AC:
993
AN:
1077568
Other (OTH)
AF:
0.000989
AC:
57
AN:
57656
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
63
126
188
251
314
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
40
80
120
160
200
<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:
0.000433
AC:
66
AN:
152284
Hom.:
0
Cov.:
33
AF XY:
0.000390
AC XY:
29
AN XY:
74454
show subpopulations
African (AFR)
AF:
0.000168
AC:
7
AN:
41566
American (AMR)
AF:
0.0000653
AC:
1
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.000853
AC:
58
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.486
Heterozygous variant carriers
0
3
7
10
14
17
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:
0.000578
Hom.:
1
Bravo
AF:
0.000382
ExAC
AF:
0.0000837
AC:
3

ClinVar

ClinVar submissions
Significance:Uncertain significance
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
5
-
not provided (5)
-
2
-
Familial isolated deficiency of vitamin E (2)
-
1
-
Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.55
BayesDel_addAF
Benign
-0.33
T
BayesDel_noAF
Benign
-0.32
CADD
Pathogenic
31
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.45
T
Eigen
Uncertain
0.40
Eigen_PC
Uncertain
0.33
FATHMM_MKL
Uncertain
0.83
D
LIST_S2
Uncertain
0.94
D
M_CAP
Pathogenic
0.86
D
MetaRNN
Uncertain
0.43
T
MetaSVM
Uncertain
0.46
D
MutationAssessor
Benign
1.6
L
PhyloP100
5.0
PrimateAI
Pathogenic
0.89
D
PROVEAN
Benign
-0.79
N
REVEL
Uncertain
0.47
Sift
Benign
0.33
T
Sift4G
Benign
0.39
T
Polyphen
1.0
D
Vest4
0.37
MVP
0.90
MPC
0.64
ClinPred
0.078
T
GERP RS
4.3
PromoterAI
0.14
Neutral
Varity_R
0.51
gMVP
0.55
Mutation Taster
=60/40
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: rs199636231; hg19: chr8-63998403; API