18-70086694-TAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-TAA

Variant names:

• chr18-70086694-TAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-T
• rs531741265
• NM_173630.4:c.4303-39_4303-11delTTTTTTTTTTTTTTTTTTTTTTTTTTTTT

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_173630.4(RTTN):​c.4303-39_4303-11delTTTTTTTTTTTTTTTTTTTTTTTTTTTTT variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000715 in 419,612 control chromosomes in the GnomAD database, with no homozygous occurrence. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 0)
  • Exomes 𝑓: 0.0000071 (0 hom.)
• Consequence: RTTN NM_173630.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.23
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RTTN	NM_173630.4	c.4303-39_4303-11delTTTTTTTTTTTTTTTTTTTTTTTTTTTTT		intron_variant	Intron 31 of 48	ENST00000640769.2	NP_775901.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RTTN	ENST00000640769.2	c.4303-39_4303-11delTTTTTTTTTTTTTTTTTTTTTTTTTTTTT		intron_variant	Intron 31 of 48	2	NM_173630.4	ENSP00000491507.1

Frequencies

GnomAD3 genomes Cov.: 0

GnomAD4 exome AF: 0.00000715 AC: 3 AN: 419612 Hom.: 0 AF XY: 0.0000133 AC XY: 3 AN XY: 226200

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 6930

American (AMR) AF: 0.0000563 AC: 1 AN: 17750

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 11714

East Asian (EAS) AF: 0.00 AC: 0 AN: 26534

South Asian (SAS) AF: 0.00 AC: 0 AN: 37168

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 29676

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1494

European-Non Finnish (NFE) AF: 0.00000746 AC: 2 AN: 268100

Other (OTH) AF: 0.00 AC: 0 AN: 20246

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.2

Splicing

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

Other links and lift over

dbSNP: rs531741265; hg19: chr18-67753930;