2-73449063-G-T

Variant names:

• chr2-73449063-G-T
• rs201154998
• NM_001378454.1:c.2536G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001378454.1(ALMS1):​c.2536G>T​(p.Gly846*) variant causes a stop gained 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 Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ALMS1 NM_001378454.1 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.503
• Publications: 0 publications found

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]

ALMS1 Gene-Disease associations (from GenCC):

• Alstrom syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Orphanet, Genomics England PanelApp

ENSG00000295621 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-73449063-G-T is Pathogenic according to our data. Variant chr2-73449063-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1425902.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALMS1	NM_001378454.1	c.2536G>T	p.Gly846*	stop_gained	Exon 8 of 23	ENST00000613296.6	NP_001365383.1
ALMS1	NM_015120.4	c.2536G>T	p.Gly846*	stop_gained	Exon 8 of 23		NP_055935.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALMS1	ENST00000613296.6	c.2536G>T	p.Gly846*	stop_gained	Exon 8 of 23	1	NM_001378454.1	ENSP00000482968.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 40

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Alstrom syndrome Pathogenic:1

Nov 19, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Gly847*) in the ALMS1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ALMS1 are known to be pathogenic (PMID: 17594715). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ALMS1-related conditions. For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.031	T
BayesDel_noAF	Benign	-0.28
CADD	Uncertain	25
DANN	Benign	0.88
DEOGEN2	Benign	0.0	.;.;.
Eigen	Benign	-0.80
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.037	N
LIST_S2	Benign	0.0	.;.;.
MetaRNN	Benign	0.0	.;.;.
MutationAssessor	Benign	0.0	.;.;.
PhyloP100		0.50
PROVEAN	Benign	0.0	.;.;.
REVEL	Benign	0.0
Sift	Pathogenic	0.0	.;.;.
Sift4G	Pathogenic	0.0	.;.;.
Vest4		0.73
GERP RS		-0.77
PromoterAI		-0.029	Neutral
Mutation Taster		=1/199	disease causing (fs/PTC)

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

Other links and lift over

dbSNP: rs201154998; hg19: chr2-73676190;