22-50079988-G-A

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM1PP3_StrongPP5_Very_Strong

The NM_015166.4(MLC1):​c.353C>T​(p.Thr118Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000991 in 1,613,946 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T118R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

MLC1
NM_015166.4 missense

Scores

7
10
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 7.12

Publications

7 publications found
Variant links:
Genes affected
MLC1 (HGNC:17082): (modulator of VRAC current 1) The function of this gene product is unknown; however, homology to other proteins suggests that it may be an integral membrane transporter. Mutations in this gene have been associated with megalencephalic leukoencephalopathy with subcortical cysts, an autosomal recessive neurological disorder. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]
MLC1 Gene-Disease associations (from GenCC):
  • megalencephalic leukoencephalopathy with subcortical cysts 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, Myriad Women’s Health
  • megalencephalic leukoencephalopathy with subcortical cysts
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 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, 6 uncertain in NM_015166.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.959
PP5
Variant 22-50079988-G-A is Pathogenic according to our data. Variant chr22-50079988-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 857173.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLC1NM_015166.4 linkc.353C>T p.Thr118Met missense_variant Exon 5 of 12 ENST00000311597.10 NP_055981.1 Q15049-1A0A024R4V4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MLC1ENST00000311597.10 linkc.353C>T p.Thr118Met missense_variant Exon 5 of 12 1 NM_015166.4 ENSP00000310375.6 Q15049-1
MLC1ENST00000395876.6 linkc.353C>T p.Thr118Met missense_variant Exon 5 of 12 1 ENSP00000379216.2 Q15049-1
MLC1ENST00000442311.1 linkc.263C>T p.Thr88Met missense_variant Exon 4 of 8 5 ENSP00000401385.1 A6PVC3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152200
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251474
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461746
Hom.:
0
Cov.:
31
AF XY:
0.0000138
AC XY:
10
AN XY:
727190
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33474
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000989
AC:
11
AN:
1111892
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
1
3
4
6
7
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:
152200
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41450
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Megalencephalic leukoencephalopathy with subcortical cysts 1 Pathogenic:2
Oct 18, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 21, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:2
Jan 25, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 118 of the MLC1 protein (p.Thr118Met). This variant is present in population databases (rs281875316, gnomAD 0.006%). This missense change has been observed in individuals with megalencephalic leukoencephalopathy with subcortical cysts (PMID: 11935341, 21160490, 25497041, 27322623). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 857173). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MLC1 protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects MLC1 function (PMID: 18757878, 22416245). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the p.Thr118 amino acid residue in MLC1. Other variant(s) that disrupt this residue have been observed in individuals with MLC1-related conditions (PMID: 11254442), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Dec 01, 2020
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate a damaging effect; transfected cells had lower protein expression compared to wild type (Xie et al., 2012).; This variant is associated with the following publications: (PMID: 27322623, 21160490, 11935341, 22416245, 18757878) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.46
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.44
CADD
Uncertain
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.46
T;T;.
Eigen
Uncertain
0.65
Eigen_PC
Uncertain
0.60
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.94
.;D;D
M_CAP
Pathogenic
0.52
D
MetaRNN
Pathogenic
0.96
D;D;D
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Benign
0.69
N;N;.
PhyloP100
7.1
PrimateAI
Uncertain
0.60
T
PROVEAN
Uncertain
-4.0
D;D;D
REVEL
Pathogenic
0.89
Sift
Uncertain
0.0010
D;D;D
Sift4G
Uncertain
0.0020
D;D;D
Polyphen
1.0
D;D;.
Vest4
0.87
MutPred
0.81
Loss of catalytic residue at T118 (P = 0.0166);Loss of catalytic residue at T118 (P = 0.0166);.;
MVP
0.96
MPC
0.91
ClinPred
0.96
D
GERP RS
5.3
Varity_R
0.39
gMVP
0.90
Mutation Taster
=1/99
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
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: rs281875316; hg19: chr22-50518417; API