chr9-69053256-TTGGG-T

Variant names:

• chr9-69053256-TTGGG-T
• rs151206121
• ENST00000484259.3:c.368_371delTGGG

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP3_Moderate

The ENST00000484259.3(FXN):​c.368_371delTGGG​(p.Tyr123LeufsTer5) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: FXN ENST00000484259.3 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.43
• Publications: 0 publications found

Genes affected

FXN (HGNC:3951): (frataxin) This nuclear gene encodes a mitochondrial protein which belongs to the FRATAXIN family. The protein functions in regulating mitochondrial iron transport and respiration. The expansion of intronic trinucleotide repeat GAA from 8-33 repeats to >90 repeats results in Friedreich ataxia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2016]

FXN Gene-Disease associations (from GenCC):

• Friedreich ataxia

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Friedreich ataxia 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• Friedreich ataxia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000285130 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FXN	NM_000144.5	c.381_384delTGGG	p.Phe127LeufsTer5	frameshift_variant, splice_region_variant	Exon 3 of 5	ENST00000484259.3	NP_000135.2
FXN	NM_181425.3	c.381_384delTGGG	p.Phe127LeufsTer5	frameshift_variant, splice_region_variant	Exon 3 of 5		NP_852090.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FXN	ENST00000484259.3	c.368_371delTGGG	p.Tyr123LeufsTer5	frameshift_variant	Exon 3 of 5	3	NM_000144.5	ENSP00000419243.2
ENSG00000285130	ENST00000642889.1	c.165+17297_165+17300delTGGG		intron_variant	Intron 1 of 24			ENSP00000493780.1

Frequencies

GnomAD3 genomes Cov.: 31

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.57		Position offset: 0
DS_DL_spliceai		0.99		Position offset: 4

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

Other links and lift over

dbSNP: rs151206121; hg19: chr9-71668172;