NM_001378454.1:c.12362G>A
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate
The NM_001378454.1(ALMS1):c.12362G>A(p.Arg4121Gln) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000198 in 1,613,962 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predicting alterations to normal splicing. 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. R4121W) has been classified as Uncertain significance.
Frequency
Consequence
NM_001378454.1 missense, splice_region
Scores
Clinical Significance
Conservation
Publications
- Alstrom syndromeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Orphanet, Genomics England PanelApp
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt | 
|---|---|---|---|---|---|---|---|---|
| ALMS1 | NM_001378454.1 | c.12362G>A | p.Arg4121Gln | missense_variant, splice_region_variant | Exon 21 of 23 | ENST00000613296.6 | NP_001365383.1 | |
| ALMS1 | NM_015120.4 | c.12362G>A | p.Arg4121Gln | missense_variant, splice_region_variant | Exon 21 of 23 | NP_055935.4 | 
Ensembl
Frequencies
GnomAD3 genomes  0.0000723  AC: 11AN: 152126Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000358  AC: 9AN: 251232 AF XY:  0.0000442   show subpopulations 
GnomAD4 exome  AF:  0.0000144  AC: 21AN: 1461718Hom.:  0  Cov.: 31 AF XY:  0.0000179  AC XY: 13AN XY: 727164 show subpopulations 
Age Distribution
GnomAD4 genome  0.0000723  AC: 11AN: 152244Hom.:  0  Cov.: 32 AF XY:  0.0000806  AC XY: 6AN XY: 74456 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Alstrom syndrome    Uncertain:4 
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This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 4122 of the ALMS1 protein (p.Arg4122Gln). This variant is present in population databases (rs376602261, gnomAD 0.02%). This missense change has been observed in individual(s) with Alstrom syndrome (PMID: 25846608). ClinVar contains an entry for this variant (Variation ID: 551196). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -
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not specified    Uncertain:1 
Variant summary: ALMS1 c.12359G>A (p.Arg4120Gln) results in a conservative amino acid change located in the ALMS motif (IPR029299) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. In addition, this variant disrupts the last nucleotide of exon 21, and therefore can affect splicing. Several computational tools predict a significant impact on normal splicing: one predicts the variant abolishes a 5' splicing donor site. Two predict the variant weakens a 5' donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 3.6e-05 in 251232 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.12359G>A has been reported in the literature in at least one individual affected with Alstrom Syndrome (e.g., Marshall_2015, Shi_2023), however without strong evidence for causality (e.g., lack of co-occurrence and co-segregation data). These reports therefore do not provide unequivocal conclusions about association of the variant with Alstrom Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 25846608, 36685911). Six submitters have reported clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
not provided    Uncertain:1 
Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; In-silico analysis, which includes splice predictors and evolutionary conservation, is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 25846608) -
Cardiovascular phenotype    Uncertain:1 
The p.R4122Q variant (also known as c.12365G>A), located in coding exon 21 of the ALMS1 gene, results from a G to A substitution at nucleotide position 12365. The arginine at codon 4122 is replaced by glutamine, an amino acid with highly similar properties. However, this change occurs in the last base pair of coding exon 21, which makes it likely to have some effect on normal mRNA splicing. This nucleotide position is highly conserved in available vertebrate species. This amino acid position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration may weaken the native splice donor site and will result in the creation or strengthening of a novel splice donor site. In addition, as a missense substitution this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at