13-99982147-C-CGGGGGGGGGG

Variant summary

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

The NM_007129.5(ZIC2):c.85_86insGGGGGGGGGG(p.Ala29GlyfsTer14) variant causes a frameshift 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 Pathogenic (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: ZIC2 NM_007129.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -0.532

Genes affected

ZIC2 (HGNC:12873): (Zic family member 2) This gene encodes a member of the ZIC family of C2H2-type zinc finger proteins. This protein functions as a transcriptional repressor and may regulate tissue specific expression of dopamine receptor D1. Expansion of an alanine repeat in the C-terminus of the encoded protein and other mutations in this gene cause holoprosencephaly type 5. Holoprosencephaly is the most common structural anomaly of the human brain. A polyhistidine tract polymorphism in this gene may be associated with increased risk of neural tube defects. This gene is closely linked to a gene encoding zinc finger protein of the cerebellum 5, a related family member on chromosome 13. [provided by RefSeq, Jul 2016]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 48 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-99982147-C-CGGGGGGGGGG is Pathogenic according to our data. Variant chr13-99982147-C-CGGGGGGGGGG is described in ClinVar as [Pathogenic]. Clinvar id is 2232044.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ZIC2	NM_007129.5	c.85_86insGGGGGGGGGG	p.Ala29GlyfsTer14	frameshift_variant	1/3	ENST00000376335.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ZIC2	ENST00000376335.8	c.85_86insGGGGGGGGGG	p.Ala29GlyfsTer14	frameshift_variant	1/3	1	NM_007129.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 15, 2021

The c.85_86insGGGGGGGGGG (p.A29Gfs*14) alteration, located in exon 1 (coding exon 1) of the ZIC2 gene, consists of an insertion of GGGGGGGGGG at position 85, causing a translational frameshift with a predicted alternate stop codon after 14 amino acids. The predicted stop codon occurs in the 5' end of the ZIC2 gene. Premature termination codons in the 5’ end of a gene have been reported to escape nonsense-mediated mRNA decay and/or lead to re-initiation (Rivas, 2015; Lindeboom, 2016; Rhee, 2017). Direct evidence for this alteration is unavailable; however, premature termination codons are typically deleterious in nature. This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). Based on the available evidence, this alteration is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr13-100634401;