chr14-60509408-C-A

Position:

• chr14-60509408-C-A

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4 BS1_Supporting BS2

The NM_007374.3(SIX6):​c.10C>A​(p.Leu4Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,447,096 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 (★). Synonymous variant affecting the same amino acid position (i.e. L4L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: SIX6 NM_007374.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.77

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 -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.31420887).
• BS1: Variant frequency is greater than expected in population afr. gnomad4_exome allele frequency = 0.000018 (26/1447096) while in subpopulation AFR AF= 0.0000299 (1/33472). AF 95% confidence interval is 0.0000154. There are 0 homozygotes in gnomad4_exome. There are 10 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAdExome4 at 26 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SIX6	NM_007374.3	c.10C>A	p.Leu4Met	missense_variant	1/2	ENST00000327720.6
C14orf39	XM_047431324.1	c.-144+5987G>T		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SIX6	ENST00000327720.6	c.10C>A	p.Leu4Met	missense_variant	1/2	1	NM_007374.3	P1
C14orf39	ENST00000556799.1	c.-144+5987G>T		intron_variant		4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000421 AC: 1 AN: 237590 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 129692

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000898

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000180 AC: 26 AN: 1447096 Hom.: 0 Cov.: 31 AF XY: 0.0000139 AC XY: 10 AN XY: 720288

Gnomad4 AFR exome AF: 0.0000299

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: 0.0000225

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000829 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 10, 2021

Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant has not been reported in the literature in individuals affected with SIX6-related conditions. This variant is present in population databases (rs372811052, ExAC 0.002%). This sequence change replaces leucine with methionine at codon 4 of the SIX6 protein (p.Leu4Met). The leucine residue is highly conserved and there is a small physicochemical difference between leucine and methionine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Uncertain	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.11	T
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.31	T
MetaSVM	Uncertain	0.69	D
MutationAssessor	Uncertain	2.8	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.80	T
PROVEAN	Benign	-1.3	N
REVEL	Uncertain	0.64
Sift	Uncertain	0.012	D
Sift4G	Benign	0.063	T
Polyphen		0.95	P
Vest4		0.42
MVP		0.83
MPC		1.1
ClinPred		0.66	D
GERP RS		3.7
Varity_R		0.33
gMVP		0.43

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: rs372811052; hg19: chr14-60976126;