9-127495380-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3
The NM_001005373.4(LRSAM1):c.1660C>T(p.Arg554Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,613,896 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 Uncertain significance (★★).
Frequency
Consequence
NM_001005373.4 missense
Scores
Clinical Significance
Conservation
Publications
- Charcot-Marie-Tooth disease axonal type 2PInheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
LRSAM1 | NM_001005373.4 | c.1660C>T | p.Arg554Trp | missense_variant | Exon 22 of 26 | ENST00000300417.11 | NP_001005373.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152226Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000278 AC: 7AN: 251358 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000192 AC: 28AN: 1461670Hom.: 0 Cov.: 31 AF XY: 0.0000138 AC XY: 10AN XY: 727142 show subpopulations
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152226Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74366 show subpopulations
ClinVar
Submissions by phenotype
Charcot-Marie-Tooth disease axonal type 2P Uncertain:2
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 554 of the LRSAM1 protein (p.Arg554Trp). This variant is present in population databases (rs757208185, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with LRSAM1-related conditions. ClinVar contains an entry for this variant (Variation ID: 472794). 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 LRSAM1 protein function with a positive predictive value of 80%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus 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. -
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. -
not specified Uncertain:1
Variant summary: LRSAM1 c.1660C>T (p.Arg554Trp) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 2.8e-05 in 251358 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.1660C>T in individuals affected with Charcot-Marie-Tooth disease axonal type 2P-AR and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 472794). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Inborn genetic diseases Uncertain:1
The c.1660C>T (p.R554W) alteration is located in exon 21 (coding exon 20) of the LRSAM1 gene. This alteration results from a C to T substitution at nucleotide position 1660, causing the arginine (R) at amino acid position 554 to be replaced by a tryptophan (W). This amino acid position is completely conserved in available vertebrate species. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at