rs1553404020

Positions:

• chr2-73451700-G-GC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001378454.1(ALMS1):​c.5176dup​(p.Leu1726ProfsTer5) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALMS1 NM_001378454.1 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 U:1
• Conservation: PhyloP100: -6.40

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 Pathogenic. Variant got 18 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 2-73451700-G-GC is Pathogenic according to our data. Variant chr2-73451700-G-GC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 553501.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALMS1	NM_001378454.1	c.5176dup	p.Leu1726ProfsTer5	frameshift_variant	8/23	ENST00000613296.6
ALMS1	NM_015120.4	c.5179dup	p.Leu1727ProfsTer5	frameshift_variant	8/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALMS1	ENST00000613296.6	c.5176dup	p.Leu1726ProfsTer5	frameshift_variant	8/23	1	NM_001378454.1	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 39

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Alstrom syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Aug 27, 2019	For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in ALMS1 are known to be pathogenic (PMID: 17594715). This variant has not been reported in the literature in individuals with ALMS1-related conditions. ClinVar contains an entry for this variant (Variation ID: 553501). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Leu1727Profs*5) in the ALMS1 gene. It is expected to result in an absent or disrupted protein product. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Feb 01, 2022	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 22, 2017	- -

not provided Uncertain:1

Uncertain significance, no assertion criteria provided

research

Gharavi Laboratory, Columbia University

Sep 16, 2018

- -

Computational scores

Source: dbNSFP v4.3

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: rs1553404020; hg19: chr2-73678827;