17-80099596-G-C

Variant summary

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

The NM_017950.4(CCDC40):c.3250G>C(p.Val1084Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,352 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1084M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CCDC40 NM_017950.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.863

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=0.05158356).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CCDC40	NM_017950.4	c.3250G>C	p.Val1084Leu	missense_variant	20/20	ENST00000397545.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CCDC40	ENST00000397545.9	c.3250G>C	p.Val1084Leu	missense_variant	20/20	5	NM_017950.4	P2
CCDC40	ENST00000574799.5	n.2787G>C		non_coding_transcript_exon_variant	16/16	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461352 Hom.: 0 Cov.: 36 AF XY: 0.00000138 AC XY: 1 AN XY: 726994

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 23, 2018

This variant has not been reported in the literature in individuals with CCDC40-related disease. 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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The leucine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant is not present in population databases (ExAC no frequency). This sequence change replaces valine with leucine at codon 1084 of the CCDC40 protein (p.Val1084Leu). The valine residue is moderately conserved and there is a small physicochemical difference between valine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.57
Cadd	Benign	13
Dann	Benign	0.94
DEOGEN2	Benign	0.062	T
Eigen	Benign	-0.79
Eigen_PC	Benign	-0.83
FATHMM_MKL	Benign	0.15	N
LIST_S2	Benign	0.63	T
M_CAP	Benign	0.011	T
MetaRNN	Benign	0.052	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.8	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-0.99	N
REVEL	Benign	0.062
Sift	Benign	0.23	T
Sift4G	Benign	0.23	T
Polyphen		0.093	B
Vest4		0.059
MutPred		0.25		Loss of methylation at K1079 (P = 0.0923);
MVP		0.12
MPC		0.18
ClinPred		0.082	T
GERP RS		-1.4
Varity_R		0.065
gMVP		0.15

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs546314844; hg19: chr17-78073395;