2-50620046-G-T

Variant names:

• chr2-50620046-G-T
• rs1259694734
• NM_001330078.2:c.1296C>A
• NRXN1 p.Asn432Lys

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001330078.2(NRXN1):​c.1296C>A​(p.Asn432Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,456,596 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. N432N) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: NRXN1 NM_001330078.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.14
• Publications: 0 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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NRXN1	NM_001330078.2	MANE Select	c.1296C>A	p.Asn432Lys	missense	Exon 8 of 23	NP_001317007.1	Q9ULB1-5
	NRXN1	NM_001135659.3		c.1416C>A	p.Asn472Lys	missense	Exon 9 of 24	NP_001129131.1	Q9ULB1-3
	NRXN1	NM_001330093.2		c.1293C>A	p.Asn431Lys	missense	Exon 8 of 23	NP_001317022.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NRXN1	ENST00000401669.7	TSL:5 MANE Select	c.1296C>A	p.Asn432Lys	missense	Exon 8 of 23	ENSP00000385017.2	Q9ULB1-5
	NRXN1	ENST00000404971.5	TSL:1	c.1416C>A	p.Asn472Lys	missense	Exon 9 of 24	ENSP00000385142.1	Q9ULB1-3
	NRXN1	ENST00000625672.2	TSL:1	c.1272C>A	p.Asn424Lys	missense	Exon 6 of 21	ENSP00000485887.1	Q9ULB1-2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1456596 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 724490

⚠️ 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: 33322

American (AMR) AF: 0.00 AC: 0 AN: 44202

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25792

East Asian (EAS) AF: 0.00 AC: 0 AN: 39526

South Asian (SAS) AF: 0.00 AC: 0 AN: 85416

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53230

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5724

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1109228

Other (OTH) AF: 0.00 AC: 0 AN: 60156

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), 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	Pathogenic	1.0
BayesDel_addAF	Uncertain	0.084	D
BayesDel_noAF	Benign	-0.12
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.48	T
Eigen	Pathogenic	0.69
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.68	D
MetaSVM	Benign	-0.30	T
MutationAssessor	Benign	1.2	L
PhyloP100		8.1
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-5.0	D
REVEL	Uncertain	0.44
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
PromoterAI		-0.059	Neutral
Varity_R		0.86
gMVP		0.77
Mutation Taster		=26/74	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs1259694734;

hg19: chr2-50847184;