chr7-66995294-CG-C

Variant names:

• chr7-66995294-CG-C
• rs761310052
• NM_016038.4:c.123delC

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_016038.4(SBDS):​c.123delC​(p.Ser41ArgfsTer18) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,442 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SBDS NM_016038.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -0.121
• Publications: 1 publications found

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]

TYW1 (HGNC:25598): (tRNA-yW synthesizing protein 1 homolog) Wybutosine (yW) is a hypermodified guanosine found in phenylalanine tRNA adjacent to the anticodon that stabilizes codon-anticodon interactions in the ribosome. In yeast, the homolog of this gene is essential for the synthesis of wybutosine. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2015]

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-66995294-CG-C is Pathogenic according to our data. Variant chr7-66995294-CG-C is described in ClinVar as [Pathogenic]. Clinvar id is 3776903.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SBDS	NM_016038.4	c.123delC	p.Ser41ArgfsTer18	frameshift_variant	Exon 1 of 5	ENST00000246868.7	NP_057122.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SBDS	ENST00000246868.7	c.123delC	p.Ser41ArgfsTer18	frameshift_variant	Exon 1 of 5	1	NM_016038.4	ENSP00000246868.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251238 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461442 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727024

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86236

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53406

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5498

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111950

Other (OTH) AF: 0.00 AC: 0 AN: 60338

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Shwachman-Diamond syndrome 1 Pathogenic:1

Feb 07, 2025

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Ser41ArgfsTer18 variant in SBDS has been reported, in the compound heterozygous state, in 1 individual with Shwachman-Diamond syndrome (PMID: 15701631), and has been identified in 0.0002% (2/1179986) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs1394707265). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. The presence of a known pseudogene, SBDSP1, can impact the reliability of allele frequencies. This variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at position 41 and leads to a termination codon 18 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Loss of function of the SBDS gene is an established disease mechanism in autosomal recessive Shwachman-Diamond syndrome. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive Shwachman-Diamond syndrome. ACMG/AMP Criteria applied: PVS1, PM3, PM2_supporting (Richards 2015). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.12
Mutation Taster		=0/200	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs761310052; hg19: chr7-66460281;