16-84159802-A-C

Variant names:

• chr16-84159802-A-C
• rs1303480013
• NM_178452.6:c.863+6A>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_178452.6(DNAAF1):​c.863+6A>C variant causes a splice region, intron 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 predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: DNAAF1 NM_178452.6 splice_region, intron
• Scores: Splicing: ADA: 0.0003479
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.151
• Publications: 0 publications found

Genes affected

DNAAF1 (HGNC:30539): (dynein axonemal assembly factor 1) The protein encoded by this gene is cilium-specific and is required for the stability of the ciliary architecture. It is involved in the regulation of microtubule-based cilia and actin-based brush border microvilli. Mutations in this gene are associated with primary ciliary dyskinesia-13. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

DNAAF1 Gene-Disease associations (from GenCC):

• primary ciliary dyskinesia 13

  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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DNAAF1	NM_178452.6	c.863+6A>C		splice_region_variant, intron_variant	Intron 6 of 11	ENST00000378553.10	NP_848547.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DNAAF1	ENST00000378553.10	c.863+6A>C		splice_region_variant, intron_variant	Intron 6 of 11	1	NM_178452.6	ENSP00000367815.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary ciliary dyskinesia Uncertain:1

Nov 22, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 525261). This variant has not been reported in the literature in individuals affected with DNAAF1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 6 of the DNAAF1 gene. It does not directly change the encoded amino acid sequence of the DNAAF1 protein. It affects a nucleotide within the consensus splice site. 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 is not likely to affect RNA splicing. 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 v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	12
DANN	Benign	0.71
PhyloP100		0.15

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00035
dbscSNV1_RF	Benign	0.018
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: rs1303480013; hg19: chr16-84193407;