chr5-55220523-G-C

Position:

• chr5-55220523-G-C

Variant summary

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

The NM_001190787.3(MCIDAS):​c.1001C>G​(p.Ala334Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000723 in 1,383,772 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: MCIDAS NM_001190787.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.74

Genes affected

MCIDAS (HGNC:40050): (multiciliate differentiation and DNA synthesis associated cell cycle protein) This gene encodes a member of the geminin family of proteins. The encoded nuclear protein is required for the generation of multiciliated cells in respiratory epithelium. Mutations in this gene cause a rare mucociliary clearance disorder associated with recurring respiratory infections in human patients, known as reduced generation of multiple motile cilia (RGMC). [provided by RefSeq, Sep 2016]

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=0.0555965).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MCIDAS	NM_001190787.3	c.1001C>G	p.Ala334Gly	missense_variant	7/7	ENST00000513312.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MCIDAS	ENST00000513312.3	c.1001C>G	p.Ala334Gly	missense_variant	7/7	1	NM_001190787.3	P1
MCIDAS	ENST00000513468.5	c.*465C>G		3_prime_UTR_variant, NMD_transcript_variant	7/7	5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.23e-7 AC: 1 AN: 1383772 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 682828

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: 9.27e-7

Gnomad4 OTH exome AF: 0.00

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 15, 2020

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 (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 and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with MCIDAS-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. This sequence change replaces alanine with glycine at codon 334 of the MCIDAS protein (p.Ala334Gly). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and glycine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.091
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.56
CADD	Benign	14
DANN	Benign	0.97
DEOGEN2	Benign	0.016	T
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.98
FATHMM_MKL	Benign	0.19	N
LIST_S2	Benign	0.58	T
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.056	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.2	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-0.53	N
REVEL	Benign	0.037
Sift	Benign	0.034	D
Sift4G	Uncertain	0.026	D
Polyphen		0.12	B
Vest4		0.088
MutPred		0.16		Gain of relative solvent accessibility (P = 0.0023);
MVP		0.014
ClinPred		0.14	T
GERP RS		3.0
Varity_R		0.051
gMVP		0.29

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: rs1745333319; hg19: chr5-54516351;