chr2-50497615-A-G

Variant names:

• chr2-50497615-A-G
• rs796052779
• NM_001330078.2:c.2597T>C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3

The NM_001330078.2(NRXN1):​c.2597T>C​(p.Ile866Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,648 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I866V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: NRXN1 NM_001330078.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 9.32
• Publications: 1 publications found

Genes affected

NRXN1 (HGNC:8008): (neurexin 1) This gene encodes a single-pass type I membrane protein that belongs to the neurexin family. Neurexins are cell-surface receptors that bind neuroligins to form Ca(2+)-dependent neurexin/neuroligin complexes at synapses in the central nervous system. This complex is required for efficient neurotransmission and is involved in the formation of synaptic contacts. Three members of this gene family have been studied in detail and are estimated to generate over 3,000 variants through the use of two alternative promoters (alpha and beta) and extensive alternative splicing in each family member. Recently, a third promoter (gamma) was identified for this gene in the 3' region. Mutations in this gene are associated with Pitt-Hopkins-like syndrome-2 and may contribute to susceptibility to schizophrenia. [provided by RefSeq, Aug 2016]

NRXN1 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• chromosome 2p16.3 deletion syndrome

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Pitt-Hopkins-like syndrome 2

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autism

  Inheritance: AD Classification: MODERATE Submitted by: G2P
• schizophrenia

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

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

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.82

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001330078.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NRXN1	NM_001330078.2	MANE Select	c.2597T>C	p.Ile866Thr	missense	Exon 14 of 23	NP_001317007.1
	NRXN1	NM_001135659.3		c.2717T>C	p.Ile906Thr	missense	Exon 15 of 24	NP_001129131.1
	NRXN1	NM_001330093.2		c.2594T>C	p.Ile865Thr	missense	Exon 14 of 23	NP_001317022.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NRXN1	ENST00000401669.7	TSL:5 MANE Select	c.2597T>C	p.Ile866Thr	missense	Exon 14 of 23	ENSP00000385017.2
	NRXN1	ENST00000404971.5	TSL:1	c.2717T>C	p.Ile906Thr	missense	Exon 15 of 24	ENSP00000385142.1
	NRXN1	ENST00000625672.2	TSL:1	c.2573T>C	p.Ile858Thr	missense	Exon 12 of 21	ENSP00000485887.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461648 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727094

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53400

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1111840

Other (OTH) AF: 0.00 AC: 0 AN: 60370

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Mar 06, 2020

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Pitt-Hopkins-like syndrome 2 Uncertain:1

Oct 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 906 of the NRXN1 protein (p.Ile906Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with NRXN1-related conditions. ClinVar contains an entry for this variant (Variation ID: 206250). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Pitt-Hopkins-like syndrome 2;C3808494:Chromosome 2p16.3 deletion syndrome Uncertain:1

Jan 03, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.49
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.47	T
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D
M_CAP	Benign	0.053	D
MetaRNN	Pathogenic	0.82	D
MetaSVM	Uncertain	0.29	D
MutationAssessor	Uncertain	2.2	M
PhyloP100		9.3
PrimateAI	Pathogenic	0.88	D
PROVEAN	Uncertain	-3.7	D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.87
MutPred		0.49		Loss of stability (P = 0.0053)
MVP		0.27
MPC		0.97
ClinPred		0.99	D
GERP RS		6.0
Varity_R		0.63
gMVP		0.63
Mutation Taster		=34/66	disease causing

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: rs796052779; hg19: chr2-50724753;