1-244053975-CAA-C

Position:

• chr1-244053975-CAA-C

Variant summary

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

The NM_205768.3(ZBTB18):​c.204_205del​(p.Asp70HisfsTer19) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ZBTB18 NM_205768.3 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.95

Genes affected

ZBTB18 (HGNC:13030): (zinc finger and BTB domain containing 18) This gene encodes a C2H2-type zinc finger protein which acts a transcriptional repressor of genes involved in neuronal development. The encoded protein recognizes a specific sequence motif and recruits components of chromatin to target genes. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2013]

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 exon, not predicted to undergo nonsense mediated mRNA decay. There are 55 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-244053975-CAA-C is Pathogenic according to our data. Variant chr1-244053975-CAA-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1703227.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ZBTB18	NM_205768.3	c.204_205del	p.Asp70HisfsTer19	frameshift_variant	2/2	ENST00000358704.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ZBTB18	ENST00000358704.4	c.204_205del	p.Asp70HisfsTer19	frameshift_variant	2/2	1	NM_205768.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intellectual disability, autosomal dominant 22 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

curation

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Aug 25, 2022

The heterozygous p.Asp70fs variant in ZBTB18 was identified in 1 individual with a neurodevelopmental disorder including autism, delayed speech and language development, intellectual disability, and motor stereotypy via a collaborative study between the Broad Institute's Center for Mendelian Genomics and the Neurodev Study (https://www.neurodevproject.org/). Trio exome analysis showed this variant to be de novo. The p.Asp70fs variant in ZBTB18 has not been previously reported in individuals with neurodevelopmental disorders and was absent from large population studies. This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 70 and leads to a premature termination codon 19 amino acids downstream. This variant falls in the last exon of the gene and is more likely to escape nonsense mediated decay (NMD) and result in a truncated protein. However, the variant is precited to remove >80% of the normal protein sequence and is therefore likely to lead to loss of function. Heterozygous loss of function of the ZBTB18 gene is strongly associated to intellectual disability. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal dominant intellectual disability. ACMG/AMP Criteria applied: PVS1_strong, PS2_supporting, PM2_supporting (Richards 2015). -

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-244217277;