Entrez ID	Official symbol	Synonyms	Description	Location	Type of protein	External annotation
1734	DIO2	5DII, D2, DIOII, SelY, TXDI2	iodothyronine deiodinase 2	14q31.1	protein-coding	Genecard

uniprot_summary

refseq_summary

Responsible for the deiodination of T4 (3,5,3,5-tetraiodothyronine) into T3 (3,5,3-triiodothyronine). Essential for providing the brain with appropriate levels of T3 during the critical period of development.

The protein encoded by this gene belongs to the iodothyronine deiodinase family. It catalyzes the conversion of prohormone thyroxine (3,5,3,5-tetraiodothyronine, T4) to the bioactive thyroid hormone (3,5,3-triiodothyronine, T3) by outer ring 5-deiodination. This gene is widely expressed, including in thyroid, placenta, pituitary and brain. It is thought to be responsible for the local production of T3, and thus important in influencing thyroid hormone action in these tissues. It has also been reported to be highly expressed in thyroids of patients with Graves disease, and in follicular adenomas. The intrathyroidal T4 to T3 conversion by this enzyme may contribute significantly to the relative increase in thyroidal T3 production in these patients. This protein is a selenoprotein containing the rare selenocysteine (Sec) amino acid at its active site, and may contain additional Sec residues. Sec is encoded by the UGA codon, which normally signals translation termination. The 3 UTRs of selenoprotein mRNAs contain a conserved stem-loop structure, designated the Sec insertion sequence (SECIS) element, that is necessary for the recognition of UGA as a Sec codon, rather than as a stop signal. Alternatively spliced transcript variants have been described for this gene.

Flase

Caregory	Description	Value	Value range ( Low - High )	Comment
PLI	The probability of being loss-of-function (LoF) intolerant	0.218	[0, ..., 1]	Genes with high pLI scores (pLI ≥ 0.9) are extremely LoF intolerant, whereby genes with low pLI scores (pLI ≤ 0.1) are LoF tolerant. The score is calculated based on high-quality exome sequence data (ExAC) for 60,706 individuals of diverse ethnicities.
Haploinsufficiency (HI) score rank	Predicted probability of exhibiting haploinsufficiency		[100, ..., 1]	High ranks (e.g. 0-10%) indicate a gene is more likely to exhibit haploinsufficiency, low ranks (e.g. 90-100%) indicate a gene is more likely to NOT exhibit haploinsufficiency (DECIPHER, PMID: 20976243). haploinsufficiency means a single functional copy of a gene is insufficient to maintain its normal function and is extremely intolerant of LoF variation.
Gene brain expressed	Queried gene is expressed in brain tissues	True	[False, True]	The gene expression data are extracted from GTEx v7 and BrainSpan. A gene with the expression value of (log 2 based (TPM+1)) at least 1 TPM/RPKM/FPKM in one or more tissues related to the brain is considered brain-expressed.
Protein brain expressed	Queried protein is expressed in brain tissues	[False, True]	The protein expression data are extracted from ProteomicsDB (v2018.09). A protein with the expression value of (log based 10 (iBAQ intensity)) at least 0.5 in one or more tissues related to the brain is considered brain-expressed protein.
Carrying LoF DNMs	Number of loss-of-function DNMs hit the queried gene	0 (Case)	[0, ..., 67] with average of 0.160	Loss of function (LoF) mutations include frameshift indels, nonsense (stop-gained) and splice-site mutations, which can result in the gene product having less or no function and can have deleterious consequences.
		0 (Control)	[0, ..., 6] with average of 0.044
Carrying missense DNMs	Number of missense DNMs hit the queried gene	0 (Case)	[0, ..., 55] with average of 0.846	Missense mutations can result in changes in protein sequences, but are commonly considered to have less deleterious impacts than LoF mutations.
		0 (Control)	[0, ..., 21] with average of 0.300
FMRP binding targets	FMRP inteacting parters	False	[False, True]	FMRP loss of function causes Fragile X syndrome (FXS). The binding targets identified crosslinking immunoprecipitation (HITS-CLIP) in mouse brains (PMID:21784246). Many FMRP targets are among genes implicated in different neuropsychiatric diseases, such as autism, schizophrenia.
Postsynaptic density (PSD)	Protein associates with postsynaptic membranes of excitatory synapses	False	[False, True]	Abnormalities with PSD proteins are linked to various neuropsychiatric diseases including neurodevelopmental disorders.
Human essential genes	-	False	[False, True]	Genes are thought to be critical for human survival.