4-127957540-T-C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001371596.2(MFSD8):​c.115A>G​(p.Ile39Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00009 in 1,611,906 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. 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. I39F) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000094 ( 0 hom. )

Consequence

MFSD8
NM_001371596.2 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 1.82

Publications

1 publications found
Variant links:
Genes affected
MFSD8 (HGNC:28486): (major facilitator superfamily domain containing 8) This gene encodes a ubiquitous integral membrane protein that contains a transporter domain and a major facilitator superfamily (MFS) domain. Other members of the major facilitator superfamily transport small solutes through chemiosmotic ion gradients. The substrate transported by this protein is unknown. The protein likely localizes to lysosomal membranes. Mutations in this gene are correlated with a variant form of late infantile-onset neuronal ceroid lipofuscinoses (vLINCL). [provided by RefSeq, Oct 2008]
MFSD8 Gene-Disease associations (from GenCC):
  • neuronal ceroid lipofuscinosis
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • neuronal ceroid lipofuscinosis 7
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, G2P
  • macular dystrophy with central cone involvement
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.12794659).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MFSD8NM_001371596.2 linkc.115A>G p.Ile39Val missense_variant Exon 2 of 12 ENST00000641686.2 NP_001358525.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MFSD8ENST00000641686.2 linkc.115A>G p.Ile39Val missense_variant Exon 2 of 12 NM_001371596.2 ENSP00000493218.2 Q8NHS3-1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152220
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000118
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000359
AC:
9
AN:
250794
AF XY:
0.00000737
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:
0.0000793
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000939
AC:
137
AN:
1459686
Hom.:
0
Cov.:
29
AF XY:
0.0000923
AC XY:
67
AN XY:
726280
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33434
American (AMR)
AF:
0.00
AC:
0
AN:
44680
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26080
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39506
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86102
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.000113
AC:
125
AN:
1110410
Other (OTH)
AF:
0.000182
AC:
11
AN:
60304
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.448
Heterozygous variant carriers
0
6
12
17
23
29
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000526
AC:
8
AN:
152220
Hom.:
0
Cov.:
32
AF XY:
0.0000672
AC XY:
5
AN XY:
74364
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41466
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000118
AC:
8
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000680
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.0000330
AC:
4
EpiCase
AF:
0.000109
EpiControl
AF:
0.000119

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Late-infantile neuronal ceroid lipofuscinosis Uncertain:1
Nov 11, 2019
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Uncertain:1
Jan 08, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The I39V variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The I39V variant was not observed with any significant frequency in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project. The I39V variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. This substitution occurs at a position where amino acids with similar properties to Isoleucine are tolerated across species, and Valine has been seen at this position in evolution. However, in silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Neuronal ceroid lipofuscinosis 7 Uncertain:1
Aug 23, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 39 of the MFSD8 protein (p.Ile39Val). This variant is present in population databases (rs201739608, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with MFSD8-related conditions. ClinVar contains an entry for this variant (Variation ID: 431874). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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
Benign
0.11
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.42
CADD
Benign
18
DANN
Benign
0.83
DEOGEN2
Benign
0.035
T;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Eigen
Benign
-0.59
Eigen_PC
Benign
-0.44
FATHMM_MKL
Benign
0.69
D
LIST_S2
Benign
0.85
.;.;T;D;T;T;D;T;T;T;D;T;T;T;T
M_CAP
Benign
0.0097
T
MetaRNN
Benign
0.13
T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.99
T
MutationAssessor
Benign
0.97
L;L;.;.;.;.;.;.;.;.;.;.;.;.;.
PhyloP100
1.8
PrimateAI
Uncertain
0.53
T
PROVEAN
Benign
-0.47
.;N;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL
Benign
0.16
Sift
Benign
0.44
.;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G
Benign
0.093
.;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Polyphen
0.040
B;B;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4
0.22
MVP
0.60
MPC
0.090
ClinPred
0.022
T
GERP RS
2.4
Varity_R
0.038
gMVP
0.47
Mutation Taster
=80/20
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: rs201739608; hg19: chr4-128878695; API