chr18-70020610-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_173630.4(RTTN):​c.6153+5G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000391 in 1,610,190 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 (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000039 ( 0 hom. )

Consequence

RTTN
NM_173630.4 splice_region, intron

Scores

2
Splicing: ADA: 0.9964
1
1

Clinical Significance

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

Conservation

PhyloP100: 2.96
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
RTTNNM_173630.4 linkuse as main transcriptc.6153+5G>A splice_region_variant, intron_variant ENST00000640769.2 NP_775901.3 Q86VV8-1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
RTTNENST00000640769.2 linkuse as main transcriptc.6153+5G>A splice_region_variant, intron_variant 2 NM_173630.4 ENSP00000491507.1 Q86VV8-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152162
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000644
AC:
16
AN:
248262
Hom.:
0
AF XY:
0.0000668
AC XY:
9
AN XY:
134686
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000116
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:
0.0000977
Gnomad OTH exome
AF:
0.000166
GnomAD4 exome
AF:
0.0000391
AC:
57
AN:
1458028
Hom.:
0
Cov.:
29
AF XY:
0.0000359
AC XY:
26
AN XY:
725222
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000112
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.0000750
Gnomad4 NFE exome
AF:
0.0000325
Gnomad4 OTH exome
AF:
0.000133
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152162
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74320
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.000288
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000588
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000774
Hom.:
0
Bravo
AF:
0.0000453

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpNov 10, 2023This sequence change falls in intron 45 of the RTTN gene. It does not directly change the encoded amino acid sequence of the RTTN protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs587780443, gnomAD 0.01%). 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: 130192). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus 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. -
Uncertain significance, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoOct 22, 2013- -
Microcephalic primordial dwarfism due to RTTN deficiency Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingPittsburgh Clinical Genomics Laboratory, University of Pittsburgh Medical CenterSep 17, 2021This sequence change is a single nucleotide substitution 5 base pairs downstream of exon 45 of RTTN. This is a previously reported variant (ClinVar) that has not been reported in patients in the literature with RTTN-related disease. This variant is rare in control population datasets (gnomAD database 17/279660 alleles or 0.006%). Multiple bioinformatic tools predict that this variant would affect gene splicing, and the G nucleotide at this position is highly conserved across the vertebrate species examined. Functiol studies confirming an effect on splicing have not been performed, to our knowledge. At this time, there is insufficient evidence to determine if this variant is pathogenic or benign. Therefore, we consider this a variant of uncertain significance. ACMG Criteria: PM2 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.40
CADD
Benign
19
DANN
Benign
0.61

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Benign
0.60
SpliceAI score (max)
0.32
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.32
Position offset: 5

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs587780443; hg19: chr18-67687846; COSMIC: COSV104550572; COSMIC: COSV104550572; API