rs121908088
Variant summary
Our verdict is Likely pathogenic. Variant got 9 ACMG points: 10P and 1B. PM2PP5_Very_StrongBP4
The NM_001206744.2(TPO):c.1978C>G(p.Gln660Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000313 in 1,614,164 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_001206744.2 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 9 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000184 AC: 28AN: 152198Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.000323 AC: 81AN: 251150Hom.: 1 AF XY: 0.000287 AC XY: 39AN XY: 135796
GnomAD4 exome AF: 0.000327 AC: 478AN: 1461848Hom.: 1 Cov.: 33 AF XY: 0.000287 AC XY: 209AN XY: 727216
GnomAD4 genome AF: 0.000184 AC: 28AN: 152316Hom.: 0 Cov.: 33 AF XY: 0.000175 AC XY: 13AN XY: 74468
ClinVar
Submissions by phenotype
Deficiency of iodide peroxidase Pathogenic:4
The TPO c.1978C>G (p.Gln660Glu) missense variant has been reported in at least four studies in which it is found in a total of 25 individuals affected with congenital hypothyroidism from 17 families, including in one in a homozygous state, in 14 in a compound heterozygous state and in 10 with unknown zygosity (Santos et al. 1999; Rodrigues et al. 2005; Deladoey et al. 2008; Al-Faisal et al. 2014). The p.Gln660Glu variant was absent from 75 controls and is reported at a frequency of 0.003326 in the Other population of the Exome Aggregation Consortium. The Gln660 residue is noted to be well conserved. Immunohistochemistry of the thyroid from an affected patient carrying the p.Gln660Glu variant with an anti-TPO antibody revealed a pattern similar to the normal control. However, the substitution of the glutamine residue by a glutamate severely affects the electrostatic potential of the residue generating an altered electrostatic environment around its catalytic site (Deladoey et al. 2008). Based on the collective data, the p.Gln660Glu variant is classified as pathogenic for congenital hypothyroidism. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
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Based on the classification scheme VCGS_Germline_v1.1.1, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss-of-function is a known mechanism of disease for this gene. (N) 0106 - This gene is known to be associated with autosomal recessive disease. (N) 0200 - Variant is predicted to result in a missense amino acid change from glutamine to glutamic acid (exon 11). (N) 0251 - Variant is heterozygous. (N) 0304 - Variant is present in gnomAD <0.01 for a recessive condition (84 heterozygotes, 1 homozygote). (P) 0502 - Missense variant with conflicting in silico predictions and/or uninformative conservation. (N) 0600 - Variant is located in an annotated domain or motif (An_peroxidase domain; PDB, DECIPHER, NCBI). (N) 0705 - No comparable variants have previous evidence for pathogenicity. (N) 0801 - Strong previous evidence of pathogenicity in unrelated individuals. This variant has been identified in several patients with both non-toxic and toxic goiter and congenital hypothyroidism as homozygotes and compound heterzoygotes (ClinVar; PMID: 18029453, 15745925, 10468986) (P) 0901 - Strong evidence for segregation with disease. This variant has been shown to segregate in 5 families (PMID: 18029453, 15745925, 10468986). (P) 1007 - No published functional evidence has been identified for this variant. (N) 1208 - Inheritance information for this variant is not currently available. (N) Legend: (P) - Pathogenic, (N) - Neutral, (B) - Benign -
not provided Pathogenic:2
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 28648508, 10468986, 18029453, 24482635, 25968604, 31589614, 31301652, 35995307, 34200080, 31430255, 34211162, 15745925, 34220711, 34248839, 35272499, Jeong2020[paper], 35507000, 36884306) -
This sequence change replaces glutamine, which is neutral and polar, with glutamic acid, which is acidic and polar, at codon 660 of the TPO protein (p.Gln660Glu). This variant is present in population databases (rs121908088, gnomAD 0.1%). This missense change has been observed in individual(s) with clinical features of thyroid dyshormonogenesis (PMID: 10468986, 15745925, 18029453, 24482635, 31430255). It has also been observed to segregate with disease in related individuals. This variant is also known as C to G at position 2068. ClinVar contains an entry for this variant (Variation ID: 4053). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on TPO protein function. For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at