2-73490975-C-T

Position:

• chr2-73490975-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001378454.1(ALMS1):​c.9016C>T​(p.His3006Tyr) 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. 12/17 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. H3006L) 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:3
• Conservation: PhyloP100: 0.00

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.036946386).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALMS1	NM_001378454.1	c.9016C>T	p.His3006Tyr	missense_variant	10/23	ENST00000613296.6
ALMS1	NM_015120.4	c.9019C>T	p.His3007Tyr	missense_variant	10/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALMS1	ENST00000613296.6	c.9016C>T	p.His3006Tyr	missense_variant	10/23	1	NM_001378454.1	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000401 AC: 1 AN: 249506 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135360

Gnomad AFR exome AF: 0.0000646

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000827 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Alstrom syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Mar 12, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Mar 13, 2022	This sequence change replaces histidine, which is basic and polar, with tyrosine, which is neutral and polar, at codon 3007 of the ALMS1 protein (p.His3007Tyr). This variant is present in population databases (rs779131632, gnomAD 0.007%). 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: 459893). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Not Available"; Align-GVGD: "Not Available". The tyrosine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 23, 2021

The p.H3007Y variant (also known as c.9019C>T), located in coding exon 10 of the ALMS1 gene, results from a C to T substitution at nucleotide position 9019. The histidine at codon 3007 is replaced by tyrosine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species, and tyrosine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.076
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	8.7
DANN	Benign	0.49
DEOGEN2	Benign	0.010	T;.;.
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.014	N
LIST_S2	Benign	0.68	T;T;T
M_CAP	Benign	0.0021	T
MetaRNN	Benign	0.037	T;T;T
MetaSVM	Benign	-0.91	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.44	T
Sift4G	Benign	0.77	T;T;T
Vest4		0.060
MVP		0.088
ClinPred		0.0089	T
GERP RS		-2.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.020
gMVP		0.051

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: rs779131632; hg19: chr2-73718102;