2-1456232-GCT-ACC

Variant names:

• chr2-1456232-GCT-ACC
• NM_001206744.2:c.769_771delGCTinsACC
• TPO p.Ala257Thr

Variant summary

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

The NM_001206744.2(TPO):​c.769_771delGCTinsACC​(p.Ala257Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, 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. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A257S) has been classified as Benign.

• Frequency: Genomes: not found (cov: 34)
• Consequence: TPO NM_001206744.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.754
• Publications: 0 publications found

Genes affected

TPO (HGNC:12015): (thyroid peroxidase) This gene encodes a membrane-bound glycoprotein. The encoded protein acts as an enzyme and plays a central role in thyroid gland function. The protein functions in the iodination of tyrosine residues in thyroglobulin and phenoxy-ester formation between pairs of iodinated tyrosines to generate the thyroid hormones, thyroxine and triiodothyronine. Mutations in this gene are associated with several disorders of thyroid hormonogenesis, including congenital hypothyroidism, congenital goiter, and thyroid hormone organification defect IIA. Multiple transcript variants encoding distinct isoforms have been identified for this gene, but the full-length nature of some variants has not been determined. [provided by RefSeq, May 2011]

TPO Gene-Disease associations (from GenCC):

• thyroid dyshormonogenesis 2A

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia
• familial thyroid dyshormonogenesis

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000231482 (HGNC:):

LALTOP (HGNC:58132):

ACMG classification

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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001206744.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TPO	NM_001206744.2	MANE Select	c.769_771delGCTinsACC	p.Ala257Thr	missense	N/A	NP_001193673.1	P07202-1
	TPO	NM_000547.6		c.769_771delGCTinsACC	p.Ala257Thr	missense	N/A	NP_000538.3
	TPO	NM_175721.3		c.769_771delGCTinsACC	p.Ala257Thr	missense	N/A	NP_783652.1	P07202-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TPO	ENST00000329066.9	TSL:1 MANE Select	c.769_771delGCTinsACC	p.Ala257Thr	missense	N/A	ENSP00000329869.4	P07202-1
	TPO	ENST00000345913.8	TSL:1	c.769_771delGCTinsACC	p.Ala257Thr	missense	N/A	ENSP00000318820.7	P07202-1
	TPO	ENST00000382201.7	TSL:1	c.769_771delGCTinsACC	p.Ala257Thr	missense	N/A	ENSP00000371636.3	P07202-2

Frequencies

GnomAD3 genomes Cov.: 34

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

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.75

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr2-1460004;