14-60509494-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP7 BS1_Supporting

The NM_007374.3(SIX6):c.96C>T(p.Arg32=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000276 in 1,450,788 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: SIX6 NM_007374.3 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.36

Genes affected

SIX6 (HGNC:10892): (SIX homeobox 6) The protein encoded by this gene is a homeobox protein that is similar to the Drosophila 'sine oculis' gene product. This gene is found in a cluster of related genes on chromosome 14 and is thought to be involved in eye development. Defects in this gene are a cause of isolated microphthalmia with cataract type 2 (MCOPCT2). [provided by RefSeq, Jul 2008]

C14orf39 (HGNC:19849): (chromosome 14 open reading frame 39) Predicted to be involved in gamete generation and meiosis I. Predicted to be located in chromosome. Predicted to be active in central element. Implicated in primary ovarian insufficiency 18 and spermatogenic failure 52. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.48).
• BP7: Synonymous conserved (PhyloP=3.36 with no splicing effect.
• BS1: Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.00000276 (4/1450788) while in subpopulation EAS AF= 0.000101 (4/39696). AF 95% confidence interval is 0.0000335. There are 0 homozygotes in gnomad4_exome. There are 3 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SIX6	NM_007374.3	c.96C>T	p.Arg32=	synonymous_variant	1/2	ENST00000327720.6
C14orf39	XM_047431324.1	c.-144+5901G>A		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SIX6	ENST00000327720.6	c.96C>T	p.Arg32=	synonymous_variant	1/2	1	NM_007374.3	P1
C14orf39	ENST00000556799.1	c.-144+5901G>A		intron_variant		4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000414 AC: 1 AN: 241718 Hom.: 0 AF XY: 0.00000761 AC XY: 1 AN XY: 131476

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000549

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000276 AC: 4 AN: 1450788 Hom.: 0 Cov.: 32 AF XY: 0.00000415 AC XY: 3 AN XY: 722176

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Anophthalmia-microphthalmia syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.48
Cadd	Benign	15
Dann	Benign	0.94

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: rs756798787; hg19: chr14-60976212;