18-23556454-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1PM5PP2BP4_Moderate
The NM_000271.5(NPC1):c.1115G>A(p.Arg372Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000452 in 1,614,102 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R372W) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000271.5 missense
Scores
Clinical Significance
Conservation
Publications
- Niemann-Pick disease, type C1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Myriad Women’s Health
- Niemann-Pick disease type C, adult neurologic onsetInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- Niemann-Pick disease type C, juvenile neurologic onsetInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- Niemann-Pick disease type C, late infantile neurologic onsetInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- Niemann-Pick disease type C, severe early infantile neurologic onsetInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- Niemann-Pick disease type C, severe perinatal formInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| NPC1 | NM_000271.5 | c.1115G>A | p.Arg372Gln | missense_variant | Exon 8 of 25 | ENST00000269228.10 | NP_000262.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| NPC1 | ENST00000269228.10 | c.1115G>A | p.Arg372Gln | missense_variant | Exon 8 of 25 | 1 | NM_000271.5 | ENSP00000269228.4 | ||
| NPC1 | ENST00000591051.1 | c.395G>A | p.Arg132Gln | missense_variant | Exon 3 of 18 | 2 | ENSP00000467636.1 | |||
| NPC1 | ENST00000540608.5 | n.1029G>A | non_coding_transcript_exon_variant | Exon 6 of 16 | 2 |
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152124Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000279 AC: 7AN: 251192 AF XY: 0.0000516 show subpopulations
GnomAD4 exome AF: 0.0000424 AC: 62AN: 1461860Hom.: 0 Cov.: 32 AF XY: 0.0000481 AC XY: 35AN XY: 727230 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000723 AC: 11AN: 152242Hom.: 0 Cov.: 33 AF XY: 0.0000537 AC XY: 4AN XY: 74440 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Niemann-Pick disease, type C1 Uncertain:3
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 372 of the NPC1 protein (p.Arg372Gln). This variant is present in population databases (rs150053420, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with NPC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 235775). 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 NPC1 protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -
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Based on the classification scheme VCGS_Germline_v1.3.3, this variant is classified as VUS-3C. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Niemann-Pick disease, type C1 and Niemann-Pick disease, type D (MIM#257220). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to glutamine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (7 heterozygotes, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (4 heterozygotes, 0 homozygotes). (I) 0503 - Missense variant consistently predicted to be tolerated by multiple in silico tools or not conserved in placental mammals with a minor amino acid change. (SB) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. However, an alternative change with a stronger Grantham change (p.Arg372Trp) has been reported in several patients with Neimann-Pickmann disease (PMID: 16098014, PMID: 30820861). (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. This variant has been reported as a VUS and been reviewed in several publications using in silico tools (ClinVar, PMID: 25764212, PMID: 30019023). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
not provided Uncertain:2
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Inborn genetic diseases Uncertain:1
The c.1115G>A (p.R372Q) alteration is located in exon 8 (coding exon 8) of the NPC1 gene. This alteration results from a G to A substitution at nucleotide position 1115, causing the arginine (R) at amino acid position 372 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
NPC1-related disorder Uncertain:1
The NPC1 c.1115G>A variant is predicted to result in the amino acid substitution p.Arg372Gln. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.013% of alleles in individuals of South Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at