5-35860850-A-G

Variant names:

• chr5-35860850-A-G
• rs886060531
• NM_002185.5:c.83-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_002185.5(IL7R):​c.83-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000684 in 1,461,108 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: IL7R NM_002185.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.46
• Publications: 2 publications found

Genes affected

IL7R (HGNC:6024): (interleukin 7 receptor) The protein encoded by this gene is a receptor for interleukin 7 (IL7). The function of this receptor requires the interleukin 2 receptor, gamma chain (IL2RG), which is a common gamma chain shared by the receptors of various cytokines, including interleukins 2, 4, 7, 9, and 15. This protein has been shown to play a critical role in V(D)J recombination during lymphocyte development. Defects in this gene may be associated with severe combined immunodeficiency (SCID). Alternatively spliced transcript variants have been found. [provided by RefSeq, Dec 2015]

IL7R Gene-Disease associations (from GenCC):

• immunodeficiency 104

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
• Omenn syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• T-B+ severe combined immunodeficiency due to IL-7Ralpha deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 8.9, offset of -22, new splice context is: tttatttgtttcattaacAGctg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IL7R	NM_002185.5	c.83-2A>G		splice_acceptor_variant, intron_variant	Intron 1 of 7	ENST00000303115.8	NP_002176.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IL7R	ENST00000303115.8	c.83-2A>G		splice_acceptor_variant, intron_variant	Intron 1 of 7	1	NM_002185.5	ENSP00000306157.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251156 AF XY: 0.00000737

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461108 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 726888

African (AFR) AF: 0.00 AC: 0 AN: 33442

American (AMR) AF: 0.0000447 AC: 2 AN: 44704

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26104

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

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

European-Non Finnish (NFE) AF: 0.00000720 AC: 8 AN: 1111370

Other (OTH) AF: 0.00 AC: 0 AN: 60364

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Immunodeficiency 104 Uncertain:1

Oct 09, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The IL7R c.83-2A>G variant occurs in a canonical splice site (acceptor) and is therefore predicted to disrupt or distort the normal gene product. It has been reported in a compound heterozygous state in one individual with severe combined immune deficiency (Felgentreff et al. 2011). Control data are unavailable for this variant, and it is not found in the 1000 Genomes Project, the Exome Sequencing Project, or the Exome Aggregation Consortium despite being found in a region with good sequencing coverage. The variant is thus presumed to be rare. Based on the limited evidence and the potential impact of splice acceptor variants, the c.83-2A>G variant is classified as a variant of unknown significance but suspicious for pathogenicity for severe combined immune deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Uncertain	0.92	D
PhyloP100		4.5
GERP RS		6.2
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.90		Position offset: -20
DS_AL_spliceai		0.99		Position offset: 2

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

Other links and lift over

dbSNP: rs886060531; hg19: chr5-35860952;