chr4-127930800-G-T
Variant summary
Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong
The NM_001371596.2(MFSD8):c.881C>A(p.Thr294Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000343 in 1,457,304 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 (★★). Synonymous variant affecting the same amino acid position (i.e. T294T) has been classified as Likely benign.
Frequency
Consequence
NM_001371596.2 missense
Scores
Clinical Significance
Conservation
Publications
- neuronal ceroid lipofuscinosisInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- neuronal ceroid lipofuscinosis 7Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, G2P
- macular dystrophy with central cone involvementInheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Pathogenic. The variant received 14 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MFSD8 | NM_001371596.2 | c.881C>A | p.Thr294Lys | missense_variant | Exon 9 of 12 | ENST00000641686.2 | NP_001358525.1 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD2 exomes AF: 0.00000802 AC: 2AN: 249426 AF XY: 0.00000742 show subpopulations
GnomAD4 exome AF: 0.00000343 AC: 5AN: 1457304Hom.: 0 Cov.: 31 AF XY: 0.00000414 AC XY: 3AN XY: 724652 show subpopulations
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Neuronal ceroid lipofuscinosis 7 Pathogenic:6
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This sequence change replaces threonine, which is neutral and polar, with lysine, which is basic and polar, at codon 294 of the MFSD8 protein (p.Thr294Lys). This variant is present in population databases (rs140948465, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of neuronal ceroid lipofuscinosis (PMID: 19177532, 19201763, 25439737). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 1006). 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 expected to disrupt MFSD8 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects MFSD8 function (PMID: 22668694). For these reasons, this variant has been classified as Pathogenic. -
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not provided Pathogenic:2
Published functional studies demonstrate a damaging effect with this variant significantly reducing MFSD8 protein function (PMID: 34910516); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 30548430, 35457110, 19177532, 34469436, 22668694, 34910516, 25439737, 19201763) -
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Inborn genetic diseases Pathogenic:1
The p.T294K pathogenic mutation (also known as c.881C>A), located in coding exon 9 of the MFSD8 gene, results from a C to A substitution at nucleotide position 881. The threonine at codon 294 is replaced by lysine, an amino acid with similar properties. This mutation has been reported in the homozygous state in multiple individuals with neuronal ceroid lipofuscinosis (NCL) and has been suggested to be a founder mutation in the Roma Gypsy population (Kousi M et al. Brain, 2009 Mar;132:810-9; (Aiello C et al. Hum. Mutat., 2009 Mar;30:E530-40). This mutation was also reported with a splice site variant in trans in an individual with NCL (Craiu D et al. Eur. J. Paediatr. Neurol., 2015 Jan;19:78-86). In COS7 cells, this mutation altered Ctsl-mediated proteolytic cleavage (Steenhuis P et al. Biochim. Biophys. Acta, 2012 Oct;1822:1617-28). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Late-infantile neuronal ceroid lipofuscinosis Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at