rs587780442

chr18-70127548-A-G

Variant summary

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

The NM_173630.4(RTTN):c.3337T>C(p.Cys1113Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,306 control chromosomes in the GnomAD database, with no homozygous occurrence. 12/21 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. C1113Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: RTTN NM_173630.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.46

Genes affected

RTTN (HGNC:18654): (rotatin) This gene encodes a large protein whose specific function is unknown. Absence of the orthologous protein in mouse results in embryonic lethality with deficient axial rotation, abnormal differentiation of the neural tube, and randomized looping of the heart tube during development. In human, mutations in this gene are associated with polymicrogyria with seizures. In human fibroblasts this protein localizes at the ciliary basal bodies. Given the intracellular localization of this protein and the phenotypic effects of mutations, this gene is suspected of playing a role in the maintenance of normal ciliary structure which in turn effects the developmental process of left-right organ specification, axial rotation, and perhaps notochord development. [provided by RefSeq, Jan 2013]

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
RTTN	NM_173630.4	c.3337T>C	p.Cys1113Arg	missense_variant	25/49	ENST00000640769.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RTTN	ENST00000640769.2	c.3337T>C	p.Cys1113Arg	missense_variant	25/49	2	NM_173630.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000803 AC: 2 AN: 248952 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135076

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000291

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461306 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 726958

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000827 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 15, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Feb 19, 2014	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.094	T
BayesDel_noAF	Benign	-0.29
Cadd	Benign	21
Dann	Benign	0.95
DEOGEN2	Benign	0.27	T;.
Eigen	Benign	0.038
Eigen_PC	Benign	-0.10
FATHMM_MKL	Uncertain	0.80	D
LIST_S2	Benign	0.62	T;T
M_CAP	Benign	0.040	D
MetaRNN	Uncertain	0.61	D;D
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.5	M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.48	T
Polyphen		1.0	D;.
Vest4		0.52
MutPred		0.59		Loss of catalytic residue at P1112 (P = 0.0054);Loss of catalytic residue at P1112 (P = 0.0054);
MVP		0.27
MPC		0.52
ClinPred		0.85	D
GERP RS		4.3
Varity_R		0.30
gMVP		0.37

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: rs587780442; hg19: chr18-67794784;