12-111447535-GA-G

Variant names:

• chr12-111447535-GA-G
• NM_005475.3:c.1228delA

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_005475.3(SH2B3):​c.1228delA​(p.Ile410fs) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 26)
• Consequence: SH2B3 NM_005475.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.11

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-111447535-GA-G is Pathogenic according to our data. Variant chr12-111447535-GA-G is described in ClinVar as [Pathogenic]. Clinvar id is 1805838.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SH2B3	NM_005475.3	c.1228delA	p.Ile410fs	frameshift_variant	Exon 6 of 8	ENST00000341259.7	NP_005466.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SH2B3	ENST00000341259.7	c.1228delA	p.Ile410fs	frameshift_variant	Exon 6 of 8	1	NM_005475.3	ENSP00000345492.2
SH2B3	ENST00000538307.1	c.622delA	p.Ile208fs	frameshift_variant	Exon 5 of 7	2		ENSP00000440597.1
ATXN2	ENST00000642389.2	n.*171-3349delT		intron_variant	Intron 26 of 26			ENSP00000496055.2

Frequencies

GnomAD3 genomes Cov.: 26

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 26

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Oct 19, 2020

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.3, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with cancers (OMIM). (I) 0111 - The inheritance pattern for this gene is unknown. Currently only somatic mutations are reported in OMIM. Germline variants in this gene are associated with predisposition to haematological malignancies (PMIDs: 26457647, 23908464, 31102422, 31173385). (I) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (premature termination codon is located at least 54 nucleotides upstream of the final exon-exon junction). (SP) 0252 - This variant is homozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0708 - Other NMD-predicted variant(s) comparable to the one identified in this case have conflicting previous evidence for pathogenicity. NMD-predicted variants have previously been reported in somatic and germline cases with mixed interpretations (ClinVar, PMIDs: 26457647, 23908464). (I) 0807 - This variant has no previous evidence of pathogenicity. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1205 - This variant has been shown to be maternally inherited (VCGS# 20G001544). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.37		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.37		Position offset: -1

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: chr12-111885339;