rs1555521110

Variant names:

• chr16-84154690-CTCT-C
• rs1555521110
• NM_178452.6:c.471_473delCTT

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PM4_Supporting

The NM_178452.6(DNAAF1):​c.471_473delCTT​(p.Phe157del) variant causes a disruptive inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DNAAF1 NM_178452.6 disruptive_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.60

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_178452.6. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DNAAF1	NM_178452.6	c.471_473delCTT	p.Phe157del	disruptive_inframe_deletion	Exon 4 of 12	ENST00000378553.10	NP_848547.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DNAAF1	ENST00000378553.10	c.471_473delCTT	p.Phe157del	disruptive_inframe_deletion	Exon 4 of 12	1	NM_178452.6	ENSP00000367815.5
DNAAF1	ENST00000567918.5	n.471_473delCTT		non_coding_transcript_exon_variant	Exon 4 of 7	1		ENSP00000455154.1
DNAAF1	ENST00000563093.5	n.471_473delCTT		non_coding_transcript_exon_variant	Exon 4 of 11	2		ENSP00000457373.1
DNAAF1	ENST00000570298.5	n.625_627delCTT		non_coding_transcript_exon_variant	Exon 4 of 11	2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461894 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary ciliary dyskinesia Uncertain:1

May 03, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the deleted amino acid is currently unknown. This sequence change deletes 3 nucleotides from exon 4 of the DNAAF1 mRNA (c.471_473delCTT). This leads to the deletion of 1 amino acid residue in the DNAAF1 protein (p.Phe157del) but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (ExAC no frequency). This variant occurs with a second rare variant (p.Asn109Lys) in DNAAF1 in an individual with primary ciliary dyskinesia (Invitae). While it is unknown if these two variants are on the same or opposite chromosomes, this observation suggests the c.471_473delCTT substitution may contribute to the cause of disease. In summary, this variant is a rare in-frame deletion with uncertain impact on protein function. While it is absent from the population and reported in affected individuals, the available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

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: rs1555521110; hg19: chr16-84188295;