NM_018943.3:c.4-21_4-8delGTTGCTTCCCTCTC

Variant names:

• chr22-18121454-CCTCGTTGCTTCCCT-C
• rs878853254
• NM_018943.3:c.4-21_4-8delGTTGCTTCCCTCTC

Variant summary

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

The NM_018943.3(TUBA8):​c.4-21_4-8delGTTGCTTCCCTCTC variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000275 in 1,454,658 control chromosomes in the GnomAD database, with no homozygous occurrence. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Uncertain significance (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: TUBA8 NM_018943.3 splice_region, intron
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 0.602
• Publications: 0 publications found

Genes affected

TUBA8 (HGNC:12410): (tubulin alpha 8) This gene encodes a member of the alpha tubulin protein family. Alpha tubulins are one of two core protein families (alpha and beta tubulins) that heterodimerize and assemble to form microtubules. Mutations in this gene are associated with polymicrogyria and optic nerve hypoplasia. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jul 2010]

TUBA8 Gene-Disease associations (from GenCC):

• polymicrogyria with optic nerve hypoplasia

  Inheritance: Unknown, AR Classification: SUPPORTIVE, LIMITED, NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet, ClinGen

ENSG00000288683 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_018943.3. 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
	TUBA8	NM_018943.3	MANE Select	c.4-21_4-8delGTTGCTTCCCTCTC		splice_region intron	N/A	NP_061816.1	Q9NY65-1
	TUBA8	NM_001193414.2		c.-195-21_-195-8delGTTGCTTCCCTCTC		splice_region intron	N/A	NP_001180343.1	Q9NY65-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TUBA8	ENST00000330423.8	TSL:1 MANE Select	c.4-21_4-8delGTTGCTTCCCTCTC		splice_region intron	N/A	ENSP00000333326.3	Q9NY65-1
	TUBA8	ENST00000416740.2	TSL:1	c.-195-21_-195-8delGTTGCTTCCCTCTC		splice_region intron	N/A	ENSP00000412646.2	Q9NY65-2
	ENSG00000288683	ENST00000474897.6	TSL:5	n.815-21_815-8delGTTGCTTCCCTCTC		splice_region intron	N/A	ENSP00000434235.2	E9PRC5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000275 AC: 4 AN: 1454658 Hom.: 0 AF XY: 0.00000276 AC XY: 2 AN XY: 724162

African (AFR) AF: 0.00 AC: 0 AN: 33366

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39650

South Asian (SAS) AF: 0.0000348 AC: 3 AN: 86086

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53392

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 9.05e-7 AC: 1 AN: 1105418

Other (OTH) AF: 0.00 AC: 0 AN: 60170

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
-	1	-	Polymicrogyria with optic nerve hypoplasia (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.60
Mutation Taster		=19/81	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs878853254; hg19: chr22-18604221;