rs373286582
Variant summary
Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_001378454.1(ALMS1):c.6299A>T(p.Lys2100Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000093 in 1,613,762 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_001378454.1 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Uncertain_significance. Variant got 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000526 AC: 8AN: 152232Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000202 AC: 5AN: 247754Hom.: 0 AF XY: 0.0000223 AC XY: 3AN XY: 134590
GnomAD4 exome AF: 0.0000972 AC: 142AN: 1461530Hom.: 0 Cov.: 37 AF XY: 0.0000853 AC XY: 62AN XY: 727064
GnomAD4 genome AF: 0.0000526 AC: 8AN: 152232Hom.: 0 Cov.: 33 AF XY: 0.0000403 AC XY: 3AN XY: 74370
ClinVar
Submissions by phenotype
Alstrom syndrome Uncertain:3
The p.Lys2101Ile variant (also referred to as p.Lys2099Ile) in the ALMS1gene has not been previously reported in association with disease. This variant has been identified in 5/112,154 European chromosomes by the Genome Aggregation Database (http://gnomad.broadinstitute.org/).•Computational tools predict that this variant does not impact protein function; however, the accuracy of in silico algorithms is limited. These data were assessed using the ACMG/AMP variant interpretation guidelines. In summary, the significance of the p.Lys2101Ile variant is uncertain. Additional information is needed to resolve the significance of this variant.[ACMG evidence codes used: PM2; BP4] -
This sequence change replaces lysine, which is basic and polar, with isoleucine, which is neutral and non-polar, at codon 2101 of the ALMS1 protein (p.Lys2101Ile). This variant is present in population databases (rs373286582, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with ALMS1-related conditions. ClinVar contains an entry for this variant (Variation ID: 403933). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Not Available"; Align-GVGD: "Not Available". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -
- -
not specified Uncertain:1
Variant summary: The ALMS1 c.6296A>T (p.Lys2099Ile, alternative name c.6302A>T) variant involves the alteration of a non-conserved nucleotide and is predicted to be benign by 4/5 in silico tools. This variant was found in 4/118064 control chromosomes from ExAC, only observed in the European (Non-Finnish) subpopulation at a frequency of 0.000062 (4/65004). This frequency is lower than the estimated maximal expected allele frequency of a pathogenic ALMS1 variant (0.0022361). The variant of interest has not, to our knowledge, been reported in affected individuals via publications and/or reputable databases/clinical diagnostic laboratories; nor evaluated for functional impact by in vivo/vitro studies. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -
not provided Uncertain:1
The testing laboratory was Invitae. Given that there is no case data available on this variant, and that it is present in control populations, we consider this a variant of uncertain significance and we do not feel it is suitable for assessing risk in healthy individuals (“predictive genetic testingâ€). Notably, the gene does not match the patient’s phenotype. The ALMS1 gene is associated with autosomal recessive Alström syndrome. To our knowledge, there are no case reports of LVNC caused by a heterozygous variant in ALMS1. There is no case data for this variant. Furthermore, loss-of-function variants in ALMS1, such as frameshift, splice site and truncating, are the most likely to cause disease. There is little evidence that missense changes, such as that of our patient, would have a clinically significant impact. The in silico prediction model SIFT predicts this variant to be deleterious. The lysine at codon 2101 is not conserved across species. There are multiple Ensemble transcripts for this gene and only one HGVS transcript. The testing lab uses a different Ensembl transcript for this gene than that which directly corresponds to the HGVS transcript (NM_015120.4 corresponds with ENST00000264448 using Mutation taster). According to the ENST00000264448 transcript, this variant would be reported as p.Lys2099Ile. The variant, using notation p.Lys2099Ile and the ENST00000264448 transcript, is present in 4 out of 59,032 individuals the ExAC dataset (http://exac.broadinstitute.org/), which currently includes variant calls on ~64,000 individuals of European, African, Latino and Asian descent (as of October 2016). Specifically, this variant is present in 4 out of 32,502 individuals of European (non-Finnish) descent. The average coverage at that site in ExAC is 30x. -
Cardiovascular phenotype Uncertain:1
The p.K2101I variant (also known as c.6302A>T), located in coding exon 8 of the ALMS1 gene, results from an A to T substitution at nucleotide position 6302. The lysine at codon 2101 is replaced by isoleucine, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, 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