rs587784490

Positions:

• chr12-49185801-G-GGAT

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PM4_Supporting

The NM_006009.4(TUBA1A):​c.564_565insATC​(p.Ile188dup) variant causes a inframe insertion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TUBA1A NM_006009.4 inframe_insertion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.48

Genes affected

TUBA1A (HGNC:20766): (tubulin alpha 1a) Microtubules of the eukaryotic cytoskeleton perform essential and diverse functions and are composed of a heterodimer of alpha and beta tubulins. The genes encoding these microtubule constituents belong to 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, which are highly conserved among species. This gene encodes alpha tubulin and is highly similar to the mouse and rat Tuba1 genes. Northern blot studies have shown that the gene expression is predominantly found in morphologically differentiated neurologic cells. This gene is one of three alpha-tubulin genes in a cluster on chromosome 12q. Mutations in this gene cause lissencephaly type 3 (LIS3) - a neurological condition characterized by microcephaly, intellectual disability, and early-onset epilepsy caused by defective neuronal migration. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2017]

TUBA1B-AS1 (HGNC:56356): (TUBA1B antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_006009.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_006009.4. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TUBA1A	NM_006009.4	c.564_565insATC	p.Ile188dup	inframe_insertion	4/4	ENST00000301071.12
TUBA1A	NM_001270399.2	c.564_565insATC	p.Ile188dup	inframe_insertion	4/4
TUBA1A	NM_001270400.2	c.459_460insATC	p.Ile153dup	inframe_insertion	4/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TUBA1A	ENST00000301071.12	c.564_565insATC	p.Ile188dup	inframe_insertion	4/4	1	NM_006009.4	P1
TUBA1B-AS1	ENST00000656133.1	n.474-2480_474-2478dup		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Lissencephaly due to TUBA1A mutation Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Aug 22, 2013

- -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs587784490; hg19: chr12-49579584;