18-70204153-A-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBS1_Supporting

The NM_173630.4(RTTN):c.330T>A(p.Asp110Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000273 in 1,614,172 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. D110D) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00019 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

RTTN
NM_173630.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 1.33

Publications

0 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: Likely_benign. The variant received -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.12800407).

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00019 (29/152348) while in subpopulation AFR AF = 0.000649 (27/41572). AF 95% confidence interval is 0.000458. There are 0 homozygotes in GnomAd4. There are 13 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RTTN	NM_173630.4 link	c.330T>A	p.Asp110Glu	missense_variant	Exon 3 of 49	ENST00000640769.2	NP_775901.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RTTN	ENST00000640769.2 link	c.330T>A	p.Asp110Glu	missense_variant	Exon 3 of 49	2	NM_173630.4	ENSP00000491507.1

Frequencies

GnomAD3 genomes

AF:

0.000191

AC:

AN:

152230

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000651

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000280

AC:

AN:

249560

AF XY:

0.0000222

show subpopulations

Gnomad AFR exome

AF:

0.000452

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000103

AC:

AN:

1461824

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727218

show subpopulations

African (AFR)

AF:

0.000448

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39690

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111964

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.435

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.000190

AC:

AN:

152348

Hom.:

Cov.:

AF XY:

0.000174

AC XY:

AN XY:

74512

show subpopulations

African (AFR)

AF:

0.000649

AC:

AN:

41572

American (AMR)

AF:

0.000131

AC:

AN:

15310

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.501

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:

0.00

Hom.:

Bravo

AF:

0.000162

ESP6500AA

AF:

0.000528

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000248

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 25, 2014

Genetic Services Laboratory, University of Chicago

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Inborn genetic diseases

Uncertain:1

Feb 14, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.330T>A (p.D110E) alteration is located in exon 3 (coding exon 3) of the RTTN gene. This alteration results from a T to A substitution at nucleotide position 330, causing the aspartic acid (D) at amino acid position 110 to be replaced by a glutamic acid (E). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

not provided

Uncertain:1

Mar 02, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with glutamic acid, which is acidic and polar, at codon 110 of the RTTN protein (p.Asp110Glu). This variant is present in population databases (rs372296200, gnomAD 0.06%). 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: 212082). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.67

BayesDel_addAF

Benign

-0.22

BayesDel_noAF

Benign

-0.18

CADD

Benign

(source)

DANN

Benign

0.95

DEOGEN2

Benign

0.23

T;.

Eigen

Uncertain

0.30

Eigen_PC

Uncertain

0.28

FATHMM_MKL

Uncertain

0.83

LIST_S2

Benign

0.77

T;T

M_CAP

Benign

0.037

MetaRNN

Benign

0.13

T;T

MetaSVM

Benign

-0.31

MutationAssessor

Uncertain

2.1

M;M

PhyloP100

1.3

PrimateAI

Uncertain

0.54

PROVEAN

Benign

0.0

.;N

REVEL

Benign

0.0

Sift

Pathogenic

0.0

.;T

Sift4G

Pathogenic

0.0

.;T

Vest4

0.0

ClinPred

0.20

GERP RS

3.2

Varity_R

0.10

gMVP

0.54

Mutation Taster

=66/34

polymorphism

(source)

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

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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