17-73338730-G-A

Variant names:

• chr17-73338730-G-A
• rs778014782
• NM_001144952.2:c.6376C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001144952.2(SDK2):​c.6376C>T​(p.Leu2126Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,038 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L2126V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SDK2 NM_001144952.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.75
• Publications: 0 publications found

Genes affected

SDK2 (HGNC:19308): (sidekick cell adhesion molecule 2) The protein encoded by this gene is a member of the immunoglobulin superfamily. The protein contains two immunoglobulin domains and thirteen fibronectin type III domains. Fibronectin type III domains are present in both extracellular and intracellular proteins and tandem repeats are known to contain binding sites for DNA, heparin and the cell surface. This protein, and a homologous mouse sequence, are very similar to the Drosophila sidekick gene product but the specific function of this superfamily member is not yet known. Evidence for alternative splicing at this gene locus has been observed but the full-length nature of additional variants has not yet been determined. [provided by RefSeq, Jul 2008]

SDK2 Gene-Disease associations (from GenCC):

• intellectual disability

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3710481).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001144952.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDK2	NM_001144952.2	MANE Select	c.6376C>T	p.Leu2126Phe	missense	Exon 45 of 45	NP_001138424.1	Q58EX2-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDK2	ENST00000392650.8	TSL:5 MANE Select	c.6376C>T	p.Leu2126Phe	missense	Exon 45 of 45	ENSP00000376421.3	Q58EX2-1
	SDK2	ENST00000424778.1	TSL:5	c.3847C>T	p.Leu1283Phe	missense	Exon 27 of 27	ENSP00000407098.1	H7C2P2
	SDK2	ENST00000410094.5	TSL:5	n.1449C>T		non_coding_transcript_exon	Exon 10 of 10

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249524 AF XY: 0.00000741

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000546

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461038 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726796

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

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

American (AMR) AF: 0.00 AC: 0 AN: 44566

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26080

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86198

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53374

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111562

Other (OTH) AF: 0.00 AC: 0 AN: 60334

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.22
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.045	T
Eigen	Uncertain	0.34
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.032	D
MetaRNN	Benign	0.37	T
MetaSVM	Benign	-0.58	T
MutationAssessor	Benign	1.4	L
PhyloP100		7.8
PrimateAI	Uncertain	0.57	T
PROVEAN	Benign	-1.8	N
REVEL	Benign	0.15
Sift	Uncertain	0.0060	D
Sift4G	Uncertain	0.013	D
Polyphen		0.50	P
Vest4		0.56
MutPred		0.35		Loss of sheet (P = 0.0104)
MVP		0.70
MPC		0.92
ClinPred		0.84	D
GERP RS		4.9
Varity_R		0.28
gMVP		0.29

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

Other links and lift over

dbSNP: rs778014782; hg19: chr17-71334869;