2-121530887-C-A

Position:

• chr2-121530887-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PP5_Moderate BP4

The NM_001395891.1(CLASP1):​c.196-562G>T variant causes a intron change. The variant allele was found at a frequency of 0.00000555 in 540,686 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 Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: CLASP1 NM_001395891.1 intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 5.74

Genes affected

CLASP1 (HGNC:17088): (cytoplasmic linker associated protein 1) CLASPs, such as CLASP1, are nonmotor microtubule-associated proteins that interact with CLIPs (e.g., CLIP170; MIM 179838). CLASP1 is involved in the regulation of microtubule dynamics at the kinetochore and throughout the spindle (Maiato et al., 2003 [PubMed 12837247]).[supplied by OMIM, Mar 2008]

RNU4ATAC (HGNC:34016): (RNA, U4atac small nuclear) The small nuclear RNA (snRNA) encoded by this gene is part of the U12-dependent minor spliceosome complex. In addition to the encoded RNA, this ribonucleoprotein complex consists of U11, U12, U5, and U6atac snRNAs. The U12-dependent spliceosome acts on approximately 700 specific introns in the human genome. Defects in this gene are a cause of microcephalic osteodysplastic primordial dwarfism type 1 (MOPD). [provided by RefSeq, Jul 2011]

CLASP1-AS1 (HGNC:55328): (CLASP1 antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-121530887-C-A is Pathogenic according to our data. Variant chr2-121530887-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 692040.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr2-121530887-C-A is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.21). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CLASP1	NM_001395891.1	c.196-562G>T		intron_variant		ENST00000696935.1	NP_001382820.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CLASP1	ENST00000696935.1	c.196-562G>T		intron_variant			NM_001395891.1	ENSP00000512981.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000555 AC: 3 AN: 540686 Hom.: 0 Cov.: 0 AF XY: 0.0000103 AC XY: 3 AN XY: 291572

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: 0.0000160

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000643

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Lowry-Wood syndrome Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Sep 11, 2020	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego	Jul 16, 2018	This variant occurs in an element of major importance for splicing in Stem II of the snRNA molecule and is therefore predicted to disrupt minor intron splicing activity (PMID: 26522830). A different nucleotide change at this position was previously reported in a compound heterozygous change in a patient with Roifman Syndrome (PMID: 26522830). The variant is absent from the ExAC and gnomAD population databases and thus is presumed to be rare. This variant was detected in trans with another CLASP1 variant classified as likely pathogenic. Based on the available evidence the variant is classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.21
CADD	Benign	19
DANN	Benign	0.95

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: rs370715569; hg19: chr2-122288463;