2-219253950-CGGGGGG-CGGGGGGGGGGGGG

Variant names:

• chr2-219253950-C-CGGGGGGG
• rs3051654
• NM_001355221.1:c.12+535_12+541dupGGGGGGG

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001355221.1(TUBA4B):​c.12+535_12+541dupGGGGGGG variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000791 in 126,424 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0000079 (0 hom., cov: 30)
• Consequence: TUBA4B NM_001355221.1 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.431
• Publications: 0 publications found

Genes affected

TUBA4B (HGNC:18637): (tubulin alpha 4b) Predicted to enable GTP binding activity. Predicted to be a structural constituent of cytoskeleton. Predicted to be involved in microtubule cytoskeleton organization and mitotic cell cycle. Predicted to be active in cytoplasm and microtubule. [provided by Alliance of Genome Resources, Apr 2022]

TUBA4A (HGNC:12407): (tubulin alpha 4a) Microtubules of the eukaryotic cytoskeleton perform essential and diverse functions and are composed of a heterodimer of alpha and beta tubulin. The genes encoding these microtubule constituents are part of the tubulin superfamily, which is composed of six distinct families. Genes from the alpha, beta and gamma tubulin families are found in all eukaryotes. The alpha and beta tubulins represent the major components of microtubules, while gamma tubulin plays a critical role in the nucleation of microtubule assembly. There are multiple alpha and beta tubulin genes and they are highly conserved among and between species. This gene encodes an alpha tubulin that is a highly conserved homolog of a rat testis-specific alpha tubulin. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2013]

TUBA4A Gene-Disease associations (from GenCC):

• amyotrophic lateral sclerosis type 22

  Inheritance: AD, Unknown Classification: MODERATE, LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen
• autosomal dominant macrothrombocytopenia

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001355221.1. 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
	TUBA4B	NM_001355221.1	MANE Select	c.12+535_12+541dupGGGGGGG		intron	N/A	NP_001342150.1	Q9H853
	TUBA4A	NM_001278552.2		c.-43+138_-43+144dupCCCCCCC		intron	N/A	NP_001265481.1	P68366-2
	TUBA4A	NM_006000.3	MANE Select	c.-99_-93dupCCCCCCC		upstream_gene	N/A	NP_005991.1	P68366-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TUBA4B	ENST00000490341.3	TSL:2 MANE Select	c.12+531_12+532insGGGGGGG		intron	N/A	ENSP00000487719.1	Q9H853
	TUBA4B	ENST00000473885.5	TSL:1	n.177+531_177+532insGGGGGGG		intron	N/A
	TUBA4B	ENST00000485041.5	TSL:1	n.177+531_177+532insGGGGGGG		intron	N/A

Frequencies

GnomAD3 genomes AF: 0.00 AC: 0 AN: 126364 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 12

GnomAD4 genome AF: 0.00000791 AC: 1 AN: 126424 Hom.: 0 Cov.: 30 AF XY: 0.0000163 AC XY: 1 AN XY: 61470

African (AFR) AF: 0.0000276 AC: 1 AN: 36272

American (AMR) AF: 0.00 AC: 0 AN: 12740

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2904

East Asian (EAS) AF: 0.00 AC: 0 AN: 4166

South Asian (SAS) AF: 0.00 AC: 0 AN: 3696

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 8134

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 220

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 55826

Other (OTH) AF: 0.00 AC: 0 AN: 1718

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.43

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs3051654; hg19: chr2-220118672;