12-111447491-GAG-AAA

Variant names:

• chr12-111447491-GAG-AAA
• NM_005475.3:c.1183_1185delGAGinsAAA
• SH2B3 p.Glu395Lys

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PS1_Moderate PP3

The NM_005475.3(SH2B3):​c.1183_1185delGAGinsAAA​(p.Glu395Lys) variant causes a missense change involving the alteration of a 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 Likely pathogenic in ClinVar.

• Frequency: Genomes: not found (cov: 30)
• Consequence: SH2B3 NM_005475.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.60
• Publications: 0 publications found

Genes affected

SH2B3 (HGNC:29605): (SH2B adaptor protein 3) This gene encodes a member of the SH2B adaptor family of proteins, which are involved in a range of signaling activities by growth factor and cytokine receptors. The encoded protein is a key negative regulator of cytokine signaling and plays a critical role in hematopoiesis. Mutations in this gene have been associated with susceptibility to celiac disease type 13 and susceptibility to insulin-dependent diabetes mellitus. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2014]

ATXN2 (HGNC:10555): (ataxin 2) This gene belongs to a group of genes that is associated with microsatellite-expansion diseases, a class of neurological and neuromuscular disorders caused by expansion of short stretches of repetitive DNA. The protein encoded by this gene has two globular domains near the N-terminus, one of which contains a clathrin-mediated trans-Golgi signal and an endoplasmic reticulum exit signal. The encoded cytoplasmic protein localizes to the endoplasmic reticulum and plasma membrane, is involved in endocytosis, and modulates mTOR signals, modifying ribosomal translation and mitochondrial function. The N-terminal region of the protein contains a polyglutamine tract of 14-31 residues that can be expanded in the pathogenic state to 32-200 residues. Intermediate length expansions of this tract increase susceptibility to amyotrophic lateral sclerosis, while long expansions of this tract result in spinocerebellar ataxia-2, an autosomal-dominantly inherited, neurodegenerative disorder. Genome-wide association studies indicate that loss-of-function mutations in this gene may be associated with susceptibility to type I diabetes, obesity and hypertension. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016]

ATXN2 Gene-Disease associations (from GenCC):

• spinocerebellar ataxia type 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PS1: Transcript NM_005475.3 (SH2B3) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005475.3. 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
	SH2B3	NM_005475.3	MANE Select	c.1183_1185delGAGinsAAA	p.Glu395Lys	missense	N/A	NP_005466.1	Q9UQQ2
	SH2B3	NM_001291424.1		c.577_579delGAGinsAAA	p.Glu193Lys	missense	N/A	NP_001278353.1	B7Z7K6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SH2B3	ENST00000341259.7	TSL:1 MANE Select	c.1183_1185delGAGinsAAA	p.Glu395Lys	missense	N/A	ENSP00000345492.2	Q9UQQ2
	SH2B3	ENST00000896496.1		c.1186_1188delGAGinsAAA	p.Glu396Lys	missense	N/A	ENSP00000566555.1
	SH2B3	ENST00000935782.1		c.1186_1188delGAGinsAAA	p.Glu396Lys	missense	N/A	ENSP00000605841.1

Frequencies

GnomAD3 genomes Cov.: 30

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

GnomAD4 genome Cov.: 30

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.6

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: chr12-111885295;