2-44942123-CT-C

Variant summary

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

The NM_005413.4(SIX3):c.20del(p.Leu7GlnfsTer244) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000055 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SIX3 NM_005413.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.70

Genes affected

SIX3 (HGNC:10889): (SIX homeobox 3) This gene encodes a member of the sine oculis homeobox transcription factor family. The encoded protein plays a role in eye development. Mutations in this gene have been associated with holoprosencephaly type 2. [provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 51 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-44942123-CT-C is Pathogenic according to our data. Variant chr2-44942123-CT-C is described in ClinVar as [Pathogenic]. Clinvar id is 2729808.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SIX3	NM_005413.4	c.20del	p.Leu7GlnfsTer244	frameshift_variant	1/2	ENST00000260653.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SIX3	ENST00000260653.5	c.20del	p.Leu7GlnfsTer244	frameshift_variant	1/2	1	NM_005413.4	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000554 AC: 8 AN: 1444074 Hom.: 0 Cov.: 32 AF XY: 0.00000556 AC XY: 4 AN XY: 718858

Gnomad4 AFR exome AF: 0.0000300

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000631

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Holoprosencephaly 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jul 17, 2023

This sequence change creates a premature translational stop signal (p.Leu7Glnfs*244) in the SIX3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SIX3 are known to be pathogenic (PMID: 18791198). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SIX3-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1403385518; hg19: chr2-45169262;