17-76732976-AGATTG-A

Position:

• chr17-76732976-AGATTG-A

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PVS1_Strong PM2 PP3 PP5_Moderate

The NM_001080510.5(METTL23):​c.86_90del​(p.Ile29SerfsTer40) variant causes a splice acceptor, coding sequence change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000213 in 1,410,672 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: METTL23 NM_001080510.5 splice_acceptor, coding_sequence
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.50

Genes affected

METTL23 (HGNC:26988): (methyltransferase 23, arginine) The protein encoded by this gene functions as a transcription factor regulator in the transcriptional pathway for human cognition. It is a partner of the alpha subunit of the GA-binding protein transcription factor. Mutations in this gene cause mild autosomal recessive intellectual disability. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.41361257 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.7, offset of 0 (no position change), new splice context is: catctttcataacttattAGagc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• PP5: Variant 17-76732976-AGATTG-A is Pathogenic according to our data. Variant chr17-76732976-AGATTG-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1184977.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
METTL23	NM_001080510.5	c.86_90del	p.Ile29SerfsTer40	splice_acceptor_variant, coding_sequence_variant	3/5	ENST00000341249.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
METTL23	ENST00000341249.11	c.86_90del	p.Ile29SerfsTer40	splice_acceptor_variant, coding_sequence_variant	3/5	1	NM_001080510.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000213 AC: 3 AN: 1410672 Hom.: 0 AF XY: 0.00000287 AC XY: 2 AN XY: 697028

Gnomad4 AFR exome AF: 0.00

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: 0.00000277

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Jun 17, 2021

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Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs756957958; hg19: chr17-74729058;