chr21-31347809-A-G

Variant names:

• chr21-31347809-A-G
• rs845930
• ENST00000653041.1:n.74A>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The ENST00000653041.1(ENSG00000286643):​n.74A>G variant causes a non coding transcript exon 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.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ENSG00000286643 ENST00000653041.1 non_coding_transcript_exon
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.488
• Publications: 2 publications found

Genes affected

ENSG00000286643 (HGNC:):

TIAM1 (HGNC:11805): (TIAM Rac1 associated GEF 1) This gene encodes a RAC1-specific guanine nucleotide exchange factor (GEF). GEFs mediate the exchange of guanosine diphosphate (GDP) for guanosine triphosphate (GTP). The binding of GTP induces a conformational change in RAC1 that allows downstream effectors to bind and transduce a signal. This gene thus regulates RAC1 signaling pathways that affect cell shape, migration, adhesion, growth, survival, and polarity, as well as influencing actin cytoskeletal formation, endocytosis, and membrane trafficking. This gene thus plays an important role in cell invasion, metastasis, and carcinogenesis. In addition to RAC1, the encoded protein activates additional Rho-like GTPases such as CDC42, RAC2, RAC3 and RHOA. This gene encodes multiple protein isoforms that experience a diverse array of intramolecular, protein-protein, and phosphorylation interactions as well as phosphoinositide binding. Both the longer and shorter isoforms have C-terminal Dbl homology (DH) and pleckstrin homology (PH) domains while only the longer isoforms of this gene have the N-terminal myristoylation site and the downstream N-terminal PH domain, ras-binding domain (RBD), and PSD-95/DlgA/ZO-1 (PDZ) domain. [provided by RefSeq, Jul 2017]

TIAM1 Gene-Disease associations (from GenCC):

• neurodevelopmental disorder with language delay and seizures

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000653041.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TIAM1	NM_001353688.1		c.-653-8387T>C		intron	N/A	NP_001340617.1
	TIAM1	NM_001353689.1		c.-368-8387T>C		intron	N/A	NP_001340618.1
	TIAM1	NM_001353690.1		c.-368-8387T>C		intron	N/A	NP_001340619.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ENSG00000286643	ENST00000653041.1		n.74A>G		non_coding_transcript_exon	Exon 1 of 3
	TIAM1	ENST00000286827.7	TSL:5	c.-368-8387T>C		intron	N/A	ENSP00000286827.3
	TIAM1	ENST00000469412.5	TSL:2	n.113-8387T>C		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

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

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	4.8
DANN	Benign	0.13
PhyloP100		0.49

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

Other links and lift over

dbSNP: rs845930; hg19: chr21-32720124;