rs763389968

chr17-80099668-G-A

Variant summary

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

The NM_017950.4(CCDC40):c.3322G>A(p.Ala1108Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,613,684 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: CCDC40 NM_017950.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.505

Genes affected

CCDC40 (HGNC:26090): (coiled-coil domain 40 molecular ruler complex subunit) This gene encodes a protein that is necessary for motile cilia function. It functions in correct left-right axis formation by regulating the assembly of the inner dynein arm and the dynein regulatory complexes, which control ciliary beat. Mutations in this gene cause ciliary dyskinesia type 15, a disorder due to defects in cilia motility. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2011]

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=0.02789089).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CCDC40	NM_017950.4	c.3322G>A	p.Ala1108Thr	missense_variant	20/20	ENST00000397545.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CCDC40	ENST00000397545.9	c.3322G>A	p.Ala1108Thr	missense_variant	20/20	5	NM_017950.4	P2
CCDC40	ENST00000574799.5	n.2859G>A		non_coding_transcript_exon_variant	16/16	1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152056 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000321 AC: 8 AN: 249230 Hom.: 0 AF XY: 0.0000222 AC XY: 3 AN XY: 135332

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000203

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000557

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 AF: 0.0000116 AC: 17 AN: 1461628 Hom.: 0 Cov.: 36 AF XY: 0.0000124 AC XY: 9 AN XY: 727112

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.000157

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152056 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74288

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000882 Hom.: 0

ExAC AF: 0.0000413 AC: 5

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary ciliary dyskinesia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 03, 2017

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. The frequency data for this variant (rs763389968) in the population databases is unreliable, as metrics indicate poor quality at this position in the ExAC database. This variant has not been reported in the literature in individuals with a CCDC40-related disease. This sequence change replaces alanine with threonine at codon 1108 of the CCDC40 protein (p.Ala1108Thr). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and threonine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Benign	-0.53	T
BayesDel_noAF	Benign	-0.73
Cadd	Benign	0.50
Dann	Benign	0.88
DEOGEN2	Benign	0.058	T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.0029	N
LIST_S2	Benign	0.40	T
M_CAP	Benign	0.0093	T
MetaRNN	Benign	0.028	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.2	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.26	T
PROVEAN	Benign	-0.38	N
REVEL	Benign	0.019
Sift	Benign	0.37	T
Sift4G	Benign	0.10	T
Polyphen		0.0	B
Vest4		0.049
MutPred		0.25		Loss of stability (P = 0.0692);
MVP		0.048
MPC		0.17
ClinPred		0.021	T
GERP RS		-9.5
Varity_R		0.021
gMVP		0.13

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: rs763389968; hg19: chr17-78073467;