2-73490231-C-A

Position:

• chr2-73490231-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001378454.1(ALMS1):​c.8272C>A​(p.Gln2758Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Q2758Q) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALMS1 NM_001378454.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.55

Genes affected

ALMS1 (HGNC:428): (ALMS1 centrosome and basal body associated protein) This gene encodes a protein containing a large tandem-repeat domain as well as additional low complexity regions. The encoded protein functions in microtubule organization, particularly in the formation and maintanance of cilia. Mutations in this gene cause Alstrom syndrome. There is a pseudogene for this gene located adjacent in the same region of chromosome 2. Alternative splice variants have been described but their full length nature has not been determined. [provided by RefSeq, Apr 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.15308037).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALMS1	NM_001378454.1	c.8272C>A	p.Gln2758Lys	missense_variant	10/23	ENST00000613296.6
ALMS1	NM_015120.4	c.8275C>A	p.Gln2759Lys	missense_variant	10/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALMS1	ENST00000613296.6	c.8272C>A	p.Gln2758Lys	missense_variant	10/23	1	NM_001378454.1	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Alstrom syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 26, 2017

Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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 has not been reported in the literature in individuals with ALMS1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamine with lysine at codon 2759 of the ALMS1 protein (p.Gln2759Lys). The glutamine residue is highly conserved and there is a small physicochemical difference between glutamine and lysine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.095
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Benign	19
DANN	Uncertain	0.99
DEOGEN2	Benign	0.064	T;.;.
Eigen	Benign	0.19
Eigen_PC	Benign	0.19
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Benign	0.79	T;T;T
M_CAP	Benign	0.0043	T
MetaRNN	Benign	0.15	T;T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	0.88	N;N
PrimateAI	Benign	0.35	T
Sift4G	Benign	0.11	T;T;T
Vest4		0.34
MVP		0.28
ClinPred		0.85	D
GERP RS		3.5
Varity_R		0.11
gMVP		0.23

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs756042345; hg19: chr2-73717358;