rs191172038
Variant summary
Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong
The NM_001371596.2(MFSD8):c.1136T>C(p.Phe379Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000294 in 1,614,166 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 17/22 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. F379I) has been classified as Uncertain significance.
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: Likely_benign. The variant received -4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MFSD8 | NM_001371596.2 | c.1136T>C | p.Phe379Ser | missense_variant | Exon 11 of 12 | ENST00000641686.2 | NP_001358525.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000309 AC: 47AN: 152184Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000287 AC: 72AN: 251270 AF XY: 0.000287 show subpopulations
GnomAD4 exome AF: 0.000292 AC: 427AN: 1461864Hom.: 1 Cov.: 32 AF XY: 0.000293 AC XY: 213AN XY: 727232 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000309 AC: 47AN: 152302Hom.: 0 Cov.: 32 AF XY: 0.000269 AC XY: 20AN XY: 74484 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Neuronal ceroid lipofuscinosis 7 Uncertain:3
This sequence change replaces phenylalanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 379 of the MFSD8 protein (p.Phe379Ser). This variant is present in population databases (rs191172038, gnomAD 0.05%). This missense change has been observed in individual(s) with cortical basal degeneration (PMID: 30382371). ClinVar contains an entry for this variant (Variation ID: 206161). 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 serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Experimental studies have shown that this missense change affects MFSD8 function (PMID: 30382371). 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. -
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
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not specified Uncertain:1
Variant summary: MFSD8 c.1136T>C (p.Phe379Ser) results in a non-conservative amino acid change located in the major facilitator superfamily domain (IPR020846) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00029 in 251270 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in MFSD8 causing Neuronal Ceroid-Lipofuscinosis (Batten Disease) (0.00029 vs 0.00094), allowing no conclusion about variant significance. c.1136T>C has been reported in the literature in the heterozygous state in an individual affected with corticobasal degeneration, although it was also found in healthy control individuals (Geier_2019). This report does not provide unequivocal conclusions about association of the variant with Neuronal Ceroid-Lipofuscinosis (Batten Disease). An experimental study found the variant resulted in an increased accumulation of protein at the cell surface versus WT, suggesting it may impact protein function by altering intercellular trafficking, however the clinical implications of this are still unclear (Geier_2019). Seven submitters have provided clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Neuronal ceroid lipofuscinosis 7;C4015371:Macular dystrophy with central cone involvement Uncertain:1
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Inborn genetic diseases Uncertain:1
The c.1136T>C (p.F379S) alteration is located in exon 12 (coding exon 11) of the MFSD8 gene. This alteration results from a T to C substitution at nucleotide position 1136, causing the phenylalanine (F) at amino acid position 379 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Late-infantile neuronal ceroid lipofuscinosis Uncertain:1
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not provided Uncertain:1
Variant identified in at least one individual with frontotemporal lobar degeneration with functional studies suggesting variant may affect MFSD8 function by altering its intracellular trafficking (PMID: 30382371); In silico analysis suggests that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 30382371) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at