8-63086022-G-T

Variant names:

• chr8-63086022-G-T
• rs1349901379
• NM_000370.3:c.-1C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000370.3(TTPA):​c.-1C>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000787 in 1,270,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.9e-7 (0 hom.)
• Consequence: TTPA NM_000370.3 5_prime_UTR
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.48
• Publications: 0 publications found

Genes affected

TTPA (HGNC:12404): (alpha tocopherol transfer protein) This gene encodes a soluble protein that binds alpha-trocopherol, a form of vitamin E, with high selectivity and affinity. This protein plays an important role in regulating vitamin E levels in the body by transporting vitamin E between membrane vesicles and facilitating the secretion of vitamin E from hepatocytes to circulating lipoproteins. Mutations in this gene cause hereditary vitamin E deficiency (ataxia with vitamin E deficiency, AVED) and retinitis pigmentosa. [provided by RefSeq, Nov 2009]

TTPA Gene-Disease associations (from GenCC):

• familial isolated deficiency of vitamin E

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Myriad Women’s Health, Labcorp Genetics (formerly Invitae)

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000370.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTPA	NM_000370.3	MANE Select	c.-1C>A		5_prime_UTR	Exon 1 of 5	NP_000361.1
	TTPA	NR_182149.1		n.32C>A		non_coding_transcript_exon	Exon 1 of 4
	TTPA	NR_182150.1		n.32C>A		non_coding_transcript_exon	Exon 1 of 6

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTPA	ENST00000260116.5	TSL:1 MANE Select	c.-1C>A		5_prime_UTR	Exon 1 of 5	ENSP00000260116.4
	TTPA	ENST00000521138.1	TSL:5	n.28C>A		non_coding_transcript_exon	Exon 1 of 2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.87e-7 AC: 1 AN: 1270738 Hom.: 0 Cov.: 31 AF XY: 0.00000160 AC XY: 1 AN XY: 625440

African (AFR) AF: 0.00 AC: 0 AN: 25808

American (AMR) AF: 0.00 AC: 0 AN: 22508

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 21442

East Asian (EAS) AF: 0.00 AC: 0 AN: 27220

South Asian (SAS) AF: 0.00 AC: 0 AN: 64486

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 31730

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3650

European-Non Finnish (NFE) AF: 9.78e-7 AC: 1 AN: 1022142

Other (OTH) AF: 0.00 AC: 0 AN: 51752

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	17
DANN	Benign	0.93
PhyloP100		2.5
PromoterAI		-0.093	Neutral

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

Other links and lift over

dbSNP: rs1349901379; hg19: chr8-63998581;