chr18-70188192-T-C

Position:

• chr18-70188192-T-C

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 2P and 10B. PM2 BP4_Strong BP6 BP7 BS1

The NM_173630.4(RTTN):​c.1221A>G​(p.Glu407=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000143 in 1,609,916 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00078 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000077 (1 hom.)
• Consequence: RTTN NM_173630.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: 0.575

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 Benign. Variant got -8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.49).
• BP6: Variant 18-70188192-T-C is Benign according to our data. Variant chr18-70188192-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 436602.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1, Benign=1}.
• BP7: Synonymous conserved (PhyloP=0.575 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000781 (119/152352) while in subpopulation AFR AF= 0.00248 (103/41592). AF 95% confidence interval is 0.00209. There are 0 homozygotes in gnomad4. There are 61 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RTTN	NM_173630.4	c.1221A>G	p.Glu407=	synonymous_variant	10/49	ENST00000640769.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RTTN	ENST00000640769.2	c.1221A>G	p.Glu407=	synonymous_variant	10/49	2	NM_173630.4	P1

Frequencies

GnomAD3 genomes AF: 0.000755 AC: 115 AN: 152234 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00239

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00191

GnomAD3 exomes AF: 0.000165 AC: 41 AN: 248394 Hom.: 0 AF XY: 0.000163 AC XY: 22 AN XY: 134728

Gnomad AFR exome AF: 0.00233

Gnomad AMR exome AF: 0.000146

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000768 AC: 112 AN: 1457564 Hom.: 1 Cov.: 28 AF XY: 0.0000703 AC XY: 51 AN XY: 725302

Gnomad4 AFR exome AF: 0.00228

Gnomad4 AMR exome AF: 0.000134

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: 0.00

Gnomad4 OTH exome AF: 0.000498

GnomAD4 genome AF: 0.000781 AC: 119 AN: 152352 Hom.: 0 Cov.: 33 AF XY: 0.000819 AC XY: 61 AN XY: 74506

Gnomad4 AFR AF: 0.00248

Gnomad4 AMR AF: 0.000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00189

Alfa AF: 0.000507 Hom.: 0

Bravo AF: 0.000888

Asia WGS AF: 0.000867 AC: 3 AN: 3476

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 22, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 12, 2017	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 08, 2024	- -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Jan 05, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.49
CADD	Benign	7.6
DANN	Benign	0.87

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: rs112327299; hg19: chr18-67855428;