rs267607236

Positions:

chr22-50076840-CTGAG-C

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PVS1PM2PP3_ModeratePP5_Very_Strong

The NM_015166.4(MLC1):c.594_597del(p.Tyr198Ter) variant causes a frameshift, splice region change. The variant allele was found at a frequency of 0.0000031 in 1,613,596 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

MLC1
NM_015166.4 frameshift, splice_region

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 6.89

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 20 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 22-50076840-CTGAG-C is Pathogenic according to our data. Variant chr22-50076840-CTGAG-C is described in ClinVar as [Pathogenic]. Clinvar id is 4720.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLC1	NM_015166.4 linkuse as main transcript	c.594_597del	p.Tyr198Ter	frameshift_variant, splice_region_variant	7/12	ENST00000311597.10	NP_055981.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLC1	ENST00000311597.10 linkuse as main transcript	c.594_597del	p.Tyr198Ter	frameshift_variant, splice_region_variant	7/12	1	NM_015166.4	ENSP00000310375	P1	Q15049-1
MLC1	ENST00000395876.6 linkuse as main transcript	c.594_597del	p.Tyr198Ter	frameshift_variant, splice_region_variant	7/12	1		ENSP00000379216	P1	Q15049-1
MLC1	ENST00000442311.1 linkuse as main transcript	c.504_507del	p.Tyr168Ter	frameshift_variant, splice_region_variant	6/8	5		ENSP00000401385

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152208

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251176

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135742

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 SAS 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:

0.00000274

AC:

AN:

1461388

Hom.:

AF XY:

0.00000138

AC XY:

AN XY:

727026

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

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:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74352

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Megalencephalic leukoencephalopathy with subcortical cysts 1

Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Nov 09, 2023	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Mar 01, 2002	- -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Jan 30, 2022	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Myelin Disorders Clinic-Children's Medical Center/Medical Genetics Lab-Tarbiat Modares University, Children's Medical Center, Pediatrics Center of Excellence,	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Molecular Diagnostics Lab, Nemours Children's Health, Delaware	Feb 09, 2021	This variant (c.593_596del, p.Tyr198*) predicts a deletion resulting in a stop codon at tyrosine 198. It has been observed at very low frequency in population databases (gnomAD) and has been described in the literature (PMID 11254442). It was found in trans with a likely pathogenic variant (c.833A>G, p.Tyr278Cys) in an affected individual. -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 05, 2023

This sequence change creates a premature translational stop signal (p.Tyr198*) in the MLC1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MLC1 are known to be pathogenic (PMID: 11254442, 16470554, 24824219). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individuals with megalencephalic leukoencephalopathy (PMID: 11254442, 11935341, 21555057). ClinVar contains an entry for this variant (Variation ID: 4720). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Megalencephalic leukoencephalopathy with subcortical cysts

Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Natera, Inc.

Jun 29, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.98

Position offset: 5

DS_DL_spliceai

0.98

Position offset: 1

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