chr7-66988465-A-G

Position:

• chr7-66988465-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_016038.4(SBDS):​c.659T>C​(p.Ile220Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SBDS NM_016038.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U: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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a chain Ribosome maturation protein SBDS (size 248) in uniprot entity SBDS_HUMAN there are 4 pathogenic changes around while only 1 benign (80%) in NM_016038.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.962

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SBDS	NM_016038.4	c.659T>C	p.Ile220Thr	missense_variant	5/5	ENST00000246868.7	NP_057122.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SBDS	ENST00000246868.7	c.659T>C	p.Ile220Thr	missense_variant	5/5	1	NM_016038.4	ENSP00000246868.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 21, 2024

The p.I220T variant (also known as c.659T>C), located in coding exon 5 of the SBDS gene, results from a T to C substitution at nucleotide position 659. The isoleucine at codon 220 is replaced by threonine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.24
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D;T
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Pathogenic	0.51	D
MetaRNN	Pathogenic	0.96	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.3	M;.
PrimateAI	Uncertain	0.70	T
PROVEAN	Uncertain	-4.0	D;.
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0030	D;.
Sift4G	Uncertain	0.0040	D;D
Polyphen		0.74	P;.
Vest4		0.72
MutPred		0.86		Loss of stability (P = 0.0065);Loss of stability (P = 0.0065);
MVP		0.98
MPC		1.4
ClinPred		0.99	D
GERP RS		3.9
Varity_R		0.85
gMVP		0.66

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: chr7-66453452;