rs121918140

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP3_ModeratePP5_Very_Strong

The NM_203395.3(IYD):​c.658G>A​(p.Ala220Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000434 in 1,614,018 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

IYD
NM_203395.3 missense

Scores

5
11
3

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 2.06

Publications

5 publications found
Variant links:
Genes affected
IYD (HGNC:21071): (iodotyrosine deiodinase) This gene encodes an enzyme that catalyzes the oxidative NADPH-dependent deiodination of mono- and diiodotyrosine, which are the halogenated byproducts of thyroid hormone production. The N-terminus of the protein functions as a membrane anchor. Mutations in this gene cause congenital hypothyroidism due to dyshormonogenesis type 4, which is also referred to as deiodinase deficiency, or iodotyrosine dehalogenase deficiency, or thyroid hormonogenesis type 4. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2009]
IYD Gene-Disease associations (from GenCC):
  • thyroid dyshormonogenesis 4
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • familial thyroid dyshormonogenesis
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.863
PP5
Variant 6-150394226-G-A is Pathogenic according to our data. Variant chr6-150394226-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 740.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IYDNM_203395.3 linkc.658G>A p.Ala220Thr missense_variant Exon 4 of 5 ENST00000344419.8 NP_981932.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IYDENST00000344419.8 linkc.658G>A p.Ala220Thr missense_variant Exon 4 of 5 1 NM_203395.3 ENSP00000343763.4

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
152148
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000191
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.0000358
AC:
9
AN:
251438
AF XY:
0.0000442
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.0000369
AC:
54
AN:
1461870
Hom.:
0
Cov.:
31
AF XY:
0.0000358
AC XY:
26
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.000520
AC:
3
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000405
AC:
45
AN:
1112002
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
4
8
11
15
19
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000105
AC:
16
AN:
152148
Hom.:
0
Cov.:
33
AF XY:
0.0000942
AC XY:
7
AN XY:
74318
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41440
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000191
AC:
13
AN:
68022
Other (OTH)
AF:
0.000479
AC:
1
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000756
Hom.:
0
Bravo
AF:
0.0000378
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Iodotyrosine deiodination defect Pathogenic:3
Jun 04, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: IYD c.658G>A (p.Ala220Thr) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 3.6e-05 in 251438 control chromosomes. c.658G>A has been observed in multiple homozygous individuals affected with Iodotyrosine deiodination defect (examples: Afink_2008, Boros_2024). These data indicate that the variant is very likely to be associated with disease.The following publications have been ascertained in the context of this evaluation (PMID: 18765512, 39106437). ClinVar contains an entry for this variant (Variation ID: 740). Based on the evidence outlined above, the variant was classified as pathogenic. -

Dec 01, 2008
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

May 13, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.34
BayesDel_addAF
Pathogenic
0.22
D
BayesDel_noAF
Pathogenic
0.27
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.61
.;D;.;.;T;D
Eigen
Uncertain
0.38
Eigen_PC
Uncertain
0.26
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Uncertain
0.97
D;D;D;D;D;D
M_CAP
Benign
0.083
D
MetaRNN
Pathogenic
0.86
D;D;D;D;D;D
MetaSVM
Uncertain
0.56
D
MutationAssessor
Pathogenic
3.3
M;M;M;.;.;.
PhyloP100
2.1
PrimateAI
Benign
0.44
T
PROVEAN
Uncertain
-3.2
D;D;D;D;D;D
REVEL
Pathogenic
0.73
Sift
Uncertain
0.0020
D;D;D;D;D;D
Sift4G
Uncertain
0.0030
D;T;D;D;D;T
Polyphen
0.98, 1.0
.;D;D;.;.;.
Vest4
0.81
MVP
0.87
MPC
0.33
ClinPred
0.88
D
GERP RS
3.2
Varity_R
0.86
gMVP
0.69
Mutation Taster
=0/100
disease causing (ClinVar)

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

Publications

Other links and lift over

dbSNP: rs121918140; hg19: chr6-150715362; COSMIC: COSV57599988; COSMIC: COSV57599988; API