chr18-70004196-A-G

Position:

• chr18-70004196-A-G

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_Strong BP6_Very_Strong BP7 BS1 BS2

The NM_173630.4(RTTN):​c.6636T>C​(p.Tyr2212=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000874 in 1,613,888 control chromosomes in the GnomAD database, including 15 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0045 (6 hom., cov: 31)
  • Exomes 𝑓: 0.00049 (9 hom.)
• Consequence: RTTN NM_173630.4 synonymous
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: -0.239

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 -21 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.95).
• BP6: Variant 18-70004196-A-G is Benign according to our data. Variant chr18-70004196-A-G is described in ClinVar as [Benign]. Clinvar id is 130196.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-0.239 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00455 (693/152318) while in subpopulation AFR AF= 0.0157 (652/41570). AF 95% confidence interval is 0.0147. There are 6 homozygotes in gnomad4. There are 338 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 6 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RTTN	NM_173630.4	c.6636T>C	p.Tyr2212=	synonymous_variant	49/49	ENST00000640769.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RTTN	ENST00000640769.2	c.6636T>C	p.Tyr2212=	synonymous_variant	49/49	2	NM_173630.4	P1

Frequencies

GnomAD3 genomes AF: 0.00449 AC: 684 AN: 152200 Hom.: 6 Cov.: 31

Gnomad AFR AF: 0.0155

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00170

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000735

Gnomad OTH AF: 0.00478

GnomAD3 exomes AF: 0.00127 AC: 317 AN: 249318 Hom.: 7 AF XY: 0.000858 AC XY: 116 AN XY: 135244

Gnomad AFR exome AF: 0.0171

Gnomad AMR exome AF: 0.00101

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: 0.0000530

Gnomad OTH exome AF: 0.00198

GnomAD4 exome AF: 0.000491 AC: 717 AN: 1461570 Hom.: 9 Cov.: 29 AF XY: 0.000419 AC XY: 305 AN XY: 727116

Gnomad4 AFR exome AF: 0.0162

Gnomad4 AMR exome AF: 0.00123

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000378

Gnomad4 OTH exome AF: 0.00119

GnomAD4 genome AF: 0.00455 AC: 693 AN: 152318 Hom.: 6 Cov.: 31 AF XY: 0.00454 AC XY: 338 AN XY: 74488

Gnomad4 AFR AF: 0.0157

Gnomad4 AMR AF: 0.00170

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000735

Gnomad4 OTH AF: 0.00473

Alfa AF: 0.00230 Hom.: 1

Bravo AF: 0.00522

Asia WGS AF: 0.00231 AC: 8 AN: 3478

EpiCase AF: 0.000164

EpiControl AF: 0.0000593

ClinVar

Significance: Benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

Likely benign, no assertion criteria provided	clinical testing	Genetic Services Laboratory, University of Chicago	-	Likely benign based on allele frequency in 1000 Genomes Project or ESP global frequency and its presence in a patient with a rare or unrelated disease phenotype. NOT Sanger confirmed. -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Oct 06, 2016	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

RTTN-related disorder Benign:1

Benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jul 18, 2019

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 25, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.95
CADD	Benign	0.89
DANN	Benign	0.30

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: rs35558429; hg19: chr18-67671432;