rs1553838206

Positions:

• chr4-15557365-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001378615.1(CC2D2A):​c.2687A>C​(p.Glu896Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. E896E) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CC2D2A NM_001378615.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.28

Genes affected

CC2D2A (HGNC:29253): (coiled-coil and C2 domain containing 2A) This gene encodes a coiled-coil and calcium binding domain protein that appears to play a critical role in cilia formation. Mutations in this gene cause Meckel syndrome type 6, as well as Joubert syndrome type 9. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CC2D2A	NM_001378615.1	c.2687A>C	p.Glu896Ala	missense_variant	21/37	ENST00000424120.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CC2D2A	ENST00000424120.6	c.2687A>C	p.Glu896Ala	missense_variant	21/37	5	NM_001378615.1	P1

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

Meckel-Gruber syndrome;C0431399:Familial aplasia of the vermis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 13, 2017

This sequence change replaces glutamic acid with alanine at codon 896 of the CC2D2A protein (p.Glu896Ala). The glutamic acid residue is highly conserved and there is a moderate physicochemical difference between glutamic acid and alanine. This variant is not present in population databases (ExAC no frequency). 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 do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with CC2D2A-related disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.49
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.60	D;D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;.
M_CAP	Benign	0.052	D
MetaRNN	Uncertain	0.70	D;D
MetaSVM	Benign	-0.55	T
MutationAssessor	Uncertain	2.5	M;M
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-4.4	D;D
REVEL	Uncertain	0.48
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0030	D;D
Polyphen		1.0	D;D
Vest4		0.77
MutPred		0.29		Loss of disorder (P = 0.0375);Loss of disorder (P = 0.0375);
MVP		0.77
MPC		0.25
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.71
gMVP		0.72

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs1553838206; hg19: chr4-15558988;