rs199422222

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PM5

The ENST00000265517.10(MTTP):c.1769G>A(p.Ser590Asn) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000249 in 1,608,752 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S590I) has been classified as Pathogenic.

Frequency

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

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

MTTP
ENST00000265517.10 missense, splice_region

Scores

Splicing: ADA: 1.000

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.16

Variant links:

Genes affected

MTTP (HGNC:7467): (microsomal triglyceride transfer protein) MTP encodes the large subunit of the heterodimeric microsomal triglyceride transfer protein. Protein disulfide isomerase (PDI) completes the heterodimeric microsomal triglyceride transfer protein, which has been shown to play a central role in lipoprotein assembly. Mutations in MTP can cause abetalipoproteinemia. [provided by RefSeq, Jul 2008]

MTTP links:

(HGNC:):

links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr4-99608977-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 14241.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
MTTP	NM_001386140.1 linkuse as main transcript	c.1769G>A	p.Ser590Asn	missense_variant, splice_region_variant	12/18	ENST00000265517.10	NP_001373069.1
MTTP	NM_000253.4 linkuse as main transcript	c.1769G>A	p.Ser590Asn	missense_variant, splice_region_variant	13/19		NP_000244.2
MTTP	NM_001300785.2 linkuse as main transcript	c.1520G>A	p.Ser507Asn	missense_variant, splice_region_variant	12/18		NP_001287714.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MTTP	ENST00000265517.10 linkuse as main transcript	c.1769G>A	p.Ser590Asn	missense_variant, splice_region_variant	12/18	1	NM_001386140.1	ENSP00000265517	P1	P55157-1
	ENST00000508578.1 linkuse as main transcript	n.128+11910C>T		intron_variant, non_coding_transcript_variant		5
MTTP	ENST00000457717.6 linkuse as main transcript	c.1769G>A	p.Ser590Asn	missense_variant, splice_region_variant	13/19	5		ENSP00000400821	P1	P55157-1
MTTP	ENST00000511045.6 linkuse as main transcript	c.1520G>A	p.Ser507Asn	missense_variant, splice_region_variant	12/18	2		ENSP00000427679

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

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:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD4 exome

AF:

0.00000206

AC:

AN:

1456604

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

724912

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.03e-7

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74332

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 07, 2022

This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 590 of the MTTP protein (p.Ser590Asn). This variant also falls at the last nucleotide of exon 13, which is part of the consensus splice site for this exon. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MTTP-related conditions. ClinVar contains an entry for this variant (Variation ID: 1350670). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.43

BayesDel_addAF

Benign

-0.052

BayesDel_noAF

Benign

-0.31

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.20

.;T;T

Eigen

Uncertain

0.60

Eigen_PC

Uncertain

0.58

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.88

D;.;D

M_CAP

Benign

0.036

MetaRNN

Uncertain

0.66

D;D;D

MetaSVM

Benign

-0.36

MutationAssessor

Pathogenic

2.9

.;M;M

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.58

PROVEAN

Benign

-0.88

N;N;N

REVEL

Benign

0.23

Sift

Benign

0.068

T;T;T

Sift4G

Uncertain

0.024

D;D;D

Polyphen

1.0

D;D;D

Vest4

0.68

MutPred

0.42

Loss of glycosylation at P615 (P = 0.0617);.;.;

MVP

0.85

MPC

0.24

ClinPred

0.95

GERP RS

5.0

Varity_R

0.35

gMVP

0.59

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

1.0

SpliceAI score (max)

0.41

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.41

Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over