NM_012144.4:c.180G>T

Variant names:

• chr9-34485240-G-T
• rs201120508
• NM_012144.4:c.180G>T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_012144.4(DNAI1):​c.180G>T​(p.Ala60Ala) variant causes a splice region, synonymous 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. A60A) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: DNAI1 NM_012144.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.9909
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0700
• Publications: 0 publications found

Genes affected

DNAI1 (HGNC:2954): (dynein axonemal intermediate chain 1) This gene encodes a member of the dynein intermediate chain family. The encoded protein is part of the dynein complex in respiratory cilia. The inner- and outer-arm dyneins, which bridge between the doublet microtubules in axonemes, are the force-generating proteins responsible for the sliding movement in axonemes. The intermediate and light chains, thought to form the base of the dynein arm, help mediate attachment and may also participate in regulating dynein activity. Mutations in this gene result in abnormal ciliary ultrastructure and function associated with primary ciliary dyskinesia and Kartagener syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

DNAI1 Gene-Disease associations (from GenCC):

• primary ciliary dyskinesia 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia
• primary ciliary dyskinesia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_012144.4. 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
	DNAI1	NM_012144.4	MANE Select	c.180G>T	p.Ala60Ala	splice_region synonymous	Exon 3 of 20	NP_036276.1
	DNAI1	NM_001281428.2		c.180G>T	p.Ala60Ala	splice_region synonymous	Exon 3 of 20	NP_001268357.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DNAI1	ENST00000242317.9	TSL:1 MANE Select	c.180G>T	p.Ala60Ala	splice_region synonymous	Exon 3 of 20	ENSP00000242317.4
	DNAI1	ENST00000614641.4	TSL:5	c.180G>T	p.Ala60Ala	splice_region synonymous	Exon 3 of 20	ENSP00000480538.1
	DNAI1	ENST00000437363.5	TSL:5	c.147G>T	p.Ala49Ala	splice_region synonymous	Exon 2 of 9	ENSP00000395396.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary ciliary dyskinesia Uncertain:1

Jul 11, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 60 of the DNAI1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the DNAI1 protein. This variant also falls at the last nucleotide of exon 3, which is part of the consensus splice site for this exon. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with DNAI1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1525651). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.28
CADD	Benign	22
DANN	Benign	0.80
PhyloP100		0.070

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.77
SpliceAI score (max)		0.55		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.55		Position offset: 4

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs201120508; hg19: chr9-34485238;