rs761713440

Variant names:

• chr2-73453358-C-A
• rs761713440
• NM_001378454.1:c.6831C>A

Your query was ambiguous. Multiple possible variants found:

• chr2-73453358-C-A
• chr2-73453358-C-G
• chr2-73453358-C-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001378454.1(ALMS1):​c.6831C>A​(p.Cys2277*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,690 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ALMS1 NM_001378454.1 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: -0.299
• 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

ACMG classification

Our verdict: Pathogenic. The variant received 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 2-73453358-C-A is Pathogenic according to our data. Variant chr2-73453358-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1073857.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALMS1	NM_001378454.1	c.6831C>A	p.Cys2277*	stop_gained	Exon 8 of 23	ENST00000613296.6	NP_001365383.1
ALMS1	NM_015120.4	c.6831C>A	p.Cys2277*	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.6831C>A	p.Cys2277*	stop_gained	Exon 8 of 23	1	NM_001378454.1	ENSP00000482968.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000805 AC: 2 AN: 248516 AF XY: 0.00000742

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000580

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461690 Hom.: 0 Cov.: 37 AF XY: 0.00000138 AC XY: 1 AN XY: 727132

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000448 AC: 2 AN: 44690

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53354

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111942

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000828 AC: 1

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Alstrom syndrome Pathogenic:2

Jan 25, 2024

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.Cys2278*) 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 present in population databases (rs761713440, gnomAD 0.006%). 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: 1073857). For these reasons, this variant has been classified as Pathogenic. -

May 05, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Jul 06, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	34
DANN	Uncertain	0.98
Eigen	Benign	0.15
Eigen_PC	Benign	-0.062
FATHMM_MKL	Benign	0.19	N
PhyloP100		-0.30
Vest4		0.81
GERP RS		-0.74
Mutation Taster		=2/198	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: rs761713440; hg19: chr2-73680485;