2-73600703-CAAAA-CAAAAA

Variant names:

• chr2-73600703-C-CA
• rs1553421626
• NM_001378454.1:c.11700dupA

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001378454.1(ALMS1):​c.11700dupA​(p.His3901ThrfsTer18) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,678 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. H3901H) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: ALMS1 NM_001378454.1 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.61
• 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, Unknown Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 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

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALMS1	NM_001378454.1	MANE Select	c.11700dupA	p.His3901ThrfsTer18	frameshift	Exon 18 of 23	NP_001365383.1	Q8TCU4-1
	ALMS1	NM_015120.4		c.11700dupA	p.His3901ThrfsTer18	frameshift	Exon 18 of 23	NP_055935.4	Q8TCU4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ALMS1	ENST00000613296.6	TSL:1 MANE Select	c.11700dupA	p.His3901ThrfsTer18	frameshift	Exon 18 of 23	ENSP00000482968.1	Q8TCU4-1
	ALMS1	ENST00000484298.5	TSL:1	c.11574dupA	p.His3859ThrfsTer18	frameshift	Exon 17 of 22	ENSP00000478155.1	A0A087WTU9
	ALMS1	ENST00000684548.1		c.11319dupA	p.His3774ThrfsTer18	frameshift	Exon 16 of 21	ENSP00000507421.1	A0A804HJA5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461678 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727114

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44698

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86212

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111886

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.6
Mutation Taster		=7/193	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1553421626; hg19: chr2-73827830;