chr18-70024756-C-G

Variant names:

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_173630.4(RTTN):c.5916G>C(p.Gln1972His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00067 in 1,613,780 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00037 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00070 ( 2 hom. )

Consequence

RTTN
NM_173630.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 2.87

Publications

4 publications found

Variant links:

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]

RTTN Gene-Disease associations (from GenCC):

microcephalic primordial dwarfism due to RTTN deficiency
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae)
bilateral generalized polymicrogyria
Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics

RTTN links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.12962458).

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000368 (56/152180) while in subpopulation NFE AF = 0.000735 (50/68032). AF 95% confidence interval is 0.000572. There are 0 homozygotes in GnomAd4. There are 26 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RTTN	NM_173630.4 link	c.5916G>C	p.Gln1972His	missense_variant	Exon 44 of 49	ENST00000640769.2	NP_775901.3	Q86VV8-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RTTN	ENST00000640769.2 link	c.5916G>C	p.Gln1972His	missense_variant	Exon 44 of 49	2	NM_173630.4	ENSP00000491507.1		Q86VV8-1

Frequencies

GnomAD3 genomes

AF:

0.000368

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.000735

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.000237

AC:

AN:

249098

AF XY:

0.000229

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000496

Gnomad OTH exome

AF:

0.000165

GnomAD4 exome

AF:

0.000701

AC:

1025

AN:

1461600

Hom.:

Cov.:

AF XY:

0.000700

AC XY:

509

AN XY:

727130

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86248

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000854

AC:

950

AN:

1111784

Other (OTH)

AF:

0.00116

AC:

AN:

60384

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.449

Heterozygous variant carriers

148

197

246

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

120

160

200

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000368

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.000350

AC XY:

AN XY:

74332

show subpopulations

African (AFR)

AF:

0.000121

AC:

AN:

41434

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000735

AC:

AN:

68032

Other (OTH)

AF:

0.000478

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.520

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000580

Hom.:

Bravo

AF:

0.000423

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000264

AC:

ESP6500EA

AF:

0.000852

AC:

ExAC

AF:

0.000182

AC:

EpiCase

AF:

0.000545

EpiControl

AF:

0.000652

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Jun 02, 2023

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Aug 15, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 1972 of the RTTN protein (p.Gln1972His). This variant is present in population databases (rs201267273, gnomAD 0.05%). This variant has not been reported in the literature in individuals affected with RTTN-related conditions. ClinVar contains an entry for this variant (Variation ID: 436606). 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. 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. -

not specified

Uncertain:1

Sep 14, 2015

Genetic Services Laboratory, University of Chicago

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Inborn genetic diseases

Uncertain:1

Jul 14, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.5916G>C (p.Q1972H) alteration is located in exon 44 (coding exon 44) of the RTTN gene. This alteration results from a G to C substitution at nucleotide position 5916, causing the glutamine (Q) at amino acid position 1972 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Microcephalic primordial dwarfism due to RTTN deficiency

Uncertain:1

Dec 22, 2021

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.30

BayesDel_addAF

Benign

-0.38

BayesDel_noAF

Benign

-0.46

CADD

Benign

(source)

DANN

Benign

0.96

DEOGEN2

Benign

0.076

T;.;.

Eigen

Benign

0.013

Eigen_PC

Benign

0.19

FATHMM_MKL

Uncertain

0.83

LIST_S2

Benign

0.80

T;T;T

M_CAP

Benign

0.0083

MetaRNN

Benign

0.13

T;T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

0.56

N;.;N

PhyloP100

2.9

PrimateAI

Uncertain

0.49

PROVEAN

Benign

-1.4

.;.;N

REVEL

Benign

0.053

Sift

Benign

0.18

.;.;T

Sift4G

Benign

0.31

.;.;T

Polyphen

0.0070

B;.;.

Vest4

0.24

MutPred

0.38

Loss of catalytic residue at Q1972 (P = 0.1047);.;Loss of catalytic residue at Q1972 (P = 0.1047);

MVP

0.46

MPC

0.068

ClinPred

0.068

GERP RS

5.5

Varity_R

0.064

gMVP

0.23

Mutation Taster

=79/21

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.050

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over