18-70054142-T-G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_173630.4(RTTN):​c.5174A>C​(p.Lys1725Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000105 in 1,612,582 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00011 ( 0 hom. )

Consequence

RTTN
NM_173630.4 missense

Scores

4
15

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.57

Publications

2 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.1829924).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
RTTNNM_173630.4 linkc.5174A>C p.Lys1725Thr missense_variant Exon 38 of 49 ENST00000640769.2 NP_775901.3 Q86VV8-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
RTTNENST00000640769.2 linkc.5174A>C p.Lys1725Thr missense_variant Exon 38 of 49 2 NM_173630.4 ENSP00000491507.1 Q86VV8-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152190
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000882
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000803
AC:
20
AN:
249016
AF XY:
0.000118
show subpopulations
Gnomad AFR exome
AF:
0.00
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:
0.000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000112
AC:
164
AN:
1460392
Hom.:
0
Cov.:
30
AF XY:
0.000118
AC XY:
86
AN XY:
726590
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33436
American (AMR)
AF:
0.00
AC:
0
AN:
44648
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39664
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86160
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.000144
AC:
160
AN:
1110884
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60328
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
7
14
22
29
36
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000394
AC:
6
AN:
152190
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000777
Hom.:
0
Bravo
AF:
0.0000416
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000519
AC:
2
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000122
AC:
1
ExAC
AF:
0.0000745
AC:
9
EpiCase
AF:
0.000219
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Microcephalic primordial dwarfism due to RTTN deficiency Uncertain:1
Sep 01, 2017
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Possible pathogenicity based on finding it once in our laboratory in trans with another missense variant in a 3-year-old female with microcephaly, craniosynostosis, dysmorphisms, fused labia, absence seizures, failure to thrive -

not provided Uncertain:1
Jul 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with threonine, which is neutral and polar, at codon 1725 of the RTTN protein (p.Lys1725Thr). This variant is present in population databases (rs200883952, gnomAD 0.02%). This missense change has been observed in individual(s) with RTTN-related conditions (PMID: 25326635). ClinVar contains an entry for this variant (Variation ID: 561099). 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: "Benign"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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
Benign
0.12
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.27
CADD
Benign
19
DANN
Uncertain
1.0
DEOGEN2
Benign
0.12
T;.
Eigen
Benign
0.11
Eigen_PC
Benign
0.090
FATHMM_MKL
Uncertain
0.77
D
LIST_S2
Benign
0.68
T;T
M_CAP
Benign
0.025
D
MetaRNN
Benign
0.18
T;T
MetaSVM
Benign
-0.82
T
MutationAssessor
Uncertain
2.7
M;M
PhyloP100
2.6
PrimateAI
Benign
0.37
T
PROVEAN
Benign
-1.2
.;N
REVEL
Benign
0.12
Sift
Benign
0.087
.;T
Sift4G
Uncertain
0.034
.;D
Polyphen
0.73
P;.
Vest4
0.65
MVP
0.38
MPC
0.12
ClinPred
0.19
T
GERP RS
5.5
Varity_R
0.12
gMVP
0.30
Mutation Taster
=88/12
polymorphism

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

Other links and lift over

dbSNP: rs200883952; hg19: chr18-67721378; API