chr20-58909186-C-A

Position:

• chr20-58909186-C-A

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_000516.7(GNAS):​c.555C>A​(p.Ile185Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. I185I) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GNAS NM_000516.7 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.27

Genes affected

GNAS (HGNC:4392): (GNAS complex locus) This locus has a highly complex imprinted expression pattern. It gives rise to maternally, paternally, and biallelically expressed transcripts that are derived from four alternative promoters and 5' exons. Some transcripts contain a differentially methylated region (DMR) at their 5' exons, and this DMR is commonly found in imprinted genes and correlates with transcript expression. An antisense transcript is produced from an overlapping locus on the opposite strand. One of the transcripts produced from this locus, and the antisense transcript, are paternally expressed noncoding RNAs, and may regulate imprinting in this region. In addition, one of the transcripts contains a second overlapping ORF, which encodes a structurally unrelated protein - Alex. Alternative splicing of downstream exons is also observed, which results in different forms of the stimulatory G-protein alpha subunit, a key element of the classical signal transduction pathway linking receptor-ligand interactions with the activation of adenylyl cyclase and a variety of cellular reponses. Multiple transcript variants encoding different isoforms have been found for this gene. Mutations in this gene result in pseudohypoparathyroidism type 1a, pseudohypoparathyroidism type 1b, Albright hereditary osteodystrophy, pseudopseudohypoparathyroidism, McCune-Albright syndrome, progressive osseus heteroplasia, polyostotic fibrous dysplasia of bone, and some pituitary tumors. [provided by RefSeq, Aug 2012]

GNAS (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.22).
• BP7: Synonymous conserved (PhyloP=1.27 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNAS	NM_000516.7	c.555C>A	p.Ile185Ile	synonymous_variant	7/13	ENST00000371085.8	NP_000507.1
GNAS	NM_016592.5	c.*461C>A		3_prime_UTR_variant	7/13	ENST00000371075.7	NP_057676.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNAS	ENST00000371085.8	c.555C>A	p.Ile185Ile	synonymous_variant	7/13	1	NM_000516.7	ENSP00000360126.3
GNAS	ENST00000676826.2	c.2487C>A	p.Ile829Ile	synonymous_variant	7/13			ENSP00000504675.2
GNAS	ENST00000371102.8	c.2442C>A	p.Ile814Ile	synonymous_variant	6/12	5		ENSP00000360143.4
GNAS	ENST00000354359.12	c.558C>A	p.Ile186Ile	synonymous_variant	7/13	1		ENSP00000346328.7
GNAS	ENST00000371095.7	c.513C>A	p.Ile171Ile	synonymous_variant	6/12	1		ENSP00000360136.3
GNAS	ENST00000470512.6	c.381C>A	p.Ile127Ile	synonymous_variant	7/13	5		ENSP00000499552.2
GNAS	ENST00000480232.6	c.381C>A	p.Ile127Ile	synonymous_variant	8/14	5		ENSP00000499545.2
GNAS	ENST00000663479.2	c.381C>A	p.Ile127Ile	synonymous_variant	7/13			ENSP00000499353.2
GNAS	ENST00000462499.6	c.336C>A	p.Ile112Ile	synonymous_variant	6/12	2		ENSP00000499758.2
GNAS	ENST00000467227.6	c.336C>A	p.Ile112Ile	synonymous_variant	7/13	3		ENSP00000499681.2
GNAS	ENST00000478585.6	c.336C>A	p.Ile112Ile	synonymous_variant	6/12	2		ENSP00000499762.2
GNAS	ENST00000481039.6	c.336C>A	p.Ile112Ile	synonymous_variant	6/12	5		ENSP00000499767.2
GNAS	ENST00000485673.6	c.336C>A	p.Ile112Ile	synonymous_variant	6/12	5		ENSP00000499334.2
GNAS	ENST00000488546.6	c.336C>A	p.Ile112Ile	synonymous_variant	6/12	5		ENSP00000499332.2
GNAS	ENST00000492907.6	c.336C>A	p.Ile112Ile	synonymous_variant	6/12	3		ENSP00000499443.2
GNAS	ENST00000371075.7	c.*461C>A		3_prime_UTR_variant	7/13	1	NM_016592.5	ENSP00000360115.3
GNAS	ENST00000453292.7	c.*416C>A		3_prime_UTR_variant	6/12	5		ENSP00000392000.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.22
CADD	Benign	15
DANN	Benign	0.83

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr20-57484241;