rs774283073

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_StrongBP6BP7BS1BS2

The NM_000370.3(TTPA):​c.558A>G​(p.Ser186Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000779 in 1,604,274 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000083 ( 2 hom. )

Consequence

TTPA
NM_000370.3 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:2

Conservation

PhyloP100: 0.686

Publications

0 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: Benign. The variant received -14 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.54).
BP6
Variant 8-63064311-T-C is Benign according to our data. Variant chr8-63064311-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 586911.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
BP7
Synonymous conserved (PhyloP=0.686 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. GnomAdExome4 allele frequency = 0.0000826 (120/1452138) while in subpopulation SAS AF = 0.00116 (99/85712). AF 95% confidence interval is 0.00097. There are 2 homozygotes in GnomAdExome4. There are 80 alleles in the male GnomAdExome4 subpopulation. Median coverage is 28. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTPANM_000370.3 linkc.558A>G p.Ser186Ser synonymous_variant Exon 4 of 5 ENST00000260116.5 NP_000361.1 P49638

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTPAENST00000260116.5 linkc.558A>G p.Ser186Ser synonymous_variant Exon 4 of 5 1 NM_000370.3 ENSP00000260116.4 P49638
TTPAENST00000521138.1 linkn.233-15708A>G intron_variant Intron 1 of 1 5

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152136
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000621
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000207
AC:
51
AN:
246398
AF XY:
0.000255
show subpopulations
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:
0.000166
GnomAD4 exome
AF:
0.0000826
AC:
120
AN:
1452138
Hom.:
2
Cov.:
28
AF XY:
0.000111
AC XY:
80
AN XY:
722846
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33270
American (AMR)
AF:
0.0000225
AC:
1
AN:
44460
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25970
East Asian (EAS)
AF:
0.0000253
AC:
1
AN:
39516
South Asian (SAS)
AF:
0.00116
AC:
99
AN:
85712
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53116
Middle Eastern (MID)
AF:
0.000348
AC:
2
AN:
5742
European-Non Finnish (NFE)
AF:
0.00000272
AC:
3
AN:
1104362
Other (OTH)
AF:
0.000233
AC:
14
AN:
59990
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
5
10
15
20
25
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.0000329
AC:
5
AN:
152136
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74308
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41430
American (AMR)
AF:
0.0000655
AC:
1
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.000621
AC:
3
AN:
4832
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:
67996
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
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

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:
0.00
Hom.:
0
Bravo
AF:
0.0000113
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Benign:2
Nov 13, 2017
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Familial isolated deficiency of vitamin E Uncertain:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.54
CADD
Benign
8.7
DANN
Benign
0.75
PhyloP100
0.69
Mutation Taster
=95/5
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs774283073; hg19: chr8-63976870; API