7-66991134-T-TA

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3 PP5_Moderate

The NM_016038.4(SBDS):c.624+2_624+3insT variant causes a splice region, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SBDS NM_016038.4 splice_region, intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.27

Genes affected

SBDS (HGNC:19440): (SBDS ribosome maturation factor) This gene encodes a highly conserved protein that plays an essential role in ribosome biogenesis. The encoded protein interacts with elongation factor-like GTPase 1 to disassociate eukaryotic initiation factor 6 from the late cytoplasmic pre-60S ribosomal subunit allowing assembly of the 80S subunit. Mutations within this gene are associated with the autosomal recessive disorder Shwachman-Bodian-Diamond syndrome. This gene has a closely linked pseudogene that is distally located. [provided by RefSeq, Jan 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-66991134-T-TA is Pathogenic according to our data. Variant chr7-66991134-T-TA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 432609.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SBDS	NM_016038.4	c.624+2_624+3insT		splice_region_variant, intron_variant		ENST00000246868.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SBDS	ENST00000246868.7	c.624+2_624+3insT		splice_region_variant, intron_variant		1	NM_016038.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000411 AC: 6 AN: 1458684 Hom.: 0 Cov.: 30 AF XY: 0.00000551 AC XY: 4 AN XY: 725500

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: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

GeneDx

Jun 02, 2017

The c.624+2dupT splice site variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The variant destroys the canonical splice donor site in intron 4 and is predicted to cause abnormal gene splicing, either leading to an abnormal message that is subject to nonsense-mediated mRNA decay, or to an abnormal protein product if the message is used for protein translation. However, the adjacent exon 4 remains in-frame. In summary, we consider this variant to be likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.73		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.66		Position offset: 42
DS_DL_spliceai		0.73		Position offset: 3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554341061; hg19: chr7-66456121;