4-127932984-C-G

Variant names:

• chr4-127932984-C-G
• rs200319160
• NM_001371596.2:c.863+1G>C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001371596.2(MFSD8):​c.863+1G>C variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000206 in 1,454,126 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MFSD8 NM_001371596.2 splice_donor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.05

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-127932984-C-G is Pathogenic according to our data. Variant chr4-127932984-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 2734672.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MFSD8	NM_001371596.2	c.863+1G>C		splice_donor_variant, intron_variant	Intron 8 of 11	ENST00000641686.2	NP_001358525.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MFSD8	ENST00000641686.2	c.863+1G>C		splice_donor_variant, intron_variant	Intron 8 of 11		NM_001371596.2	ENSP00000493218.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000797 AC: 2 AN: 251090 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135684

Gnomad AFR exome AF: 0.0000615

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1454126 Hom.: 0 Cov.: 28 AF XY: 0.00 AC XY: 0 AN XY: 724020

Gnomad4 AFR exome AF: 0.0000300

Gnomad4 AMR exome AF: 0.0000448

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neuronal ceroid lipofuscinosis 7 Pathogenic:1

Jan 10, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is present in population databases (no rsID available, gnomAD 0.007%). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Disruption of this splice site has been observed in individual(s) with clinical features of neuronal ceroid lipofuscinosis (PMID: 19177532; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This sequence change affects a donor splice site in intron 9 of the MFSD8 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MFSD8 are known to be pathogenic (PMID: 19177532, 25227500, 28586915). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.97	D
GERP RS		4.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.98		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs200319160; hg19: chr4-128854139;