NM_001378454.1:c.3799G>T

Variant names:

• chr2-73450326-G-T
• rs770278707
• NM_001378454.1:c.3799G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001378454.1(ALMS1):​c.3799G>T​(p.Val1267Phe) 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. 13/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1267L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALMS1 NM_001378454.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -5.88
• 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06811008).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001378454.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALMS1	NM_001378454.1	MANE Select	c.3799G>T	p.Val1267Phe	missense	Exon 8 of 23	NP_001365383.1
	ALMS1	NM_015120.4		c.3799G>T	p.Val1267Phe	missense	Exon 8 of 23	NP_055935.4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALMS1	ENST00000613296.6	TSL:1 MANE Select	c.3799G>T	p.Val1267Phe	missense	Exon 8 of 23	ENSP00000482968.1
	ALMS1	ENST00000484298.5	TSL:1	c.3673G>T	p.Val1225Phe	missense	Exon 7 of 22	ENSP00000478155.1
	ALMS1	ENST00000684548.1		c.3418G>T	p.Val1140Phe	missense	Exon 6 of 21	ENSP00000507421.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 40

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Dec 02, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Alstrom syndrome Uncertain:1

Feb 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant has not been reported in the literature in individuals affected with ALMS1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 1268 of the ALMS1 protein (p.Val1268Phe).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.59
CADD	Benign	0.025
DANN	Benign	0.96
DEOGEN2	Benign	0.024	T
Eigen	Benign	-1.5
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.012	N
LIST_S2	Benign	0.21	T
M_CAP	Benign	0.011	T
MetaRNN	Benign	0.068	T
MetaSVM	Benign	-1.1	T
PhyloP100		-5.9
PrimateAI	Benign	0.26	T
Sift4G	Benign	0.065	T
Vest4		0.18
MVP		0.067
ClinPred		0.16	T
GERP RS		-5.0
Varity_R		0.033
gMVP		0.016
Mutation Taster		=97/3	polymorphism

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: rs770278707; hg19: chr2-73677453;