2-50538359-C-A

Variant names:

• chr2-50538359-C-A
• rs199714221
• NM_001330078.2:c.2037G>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_001330078.2(NRXN1):​c.2037G>T​(p.Pro679Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,696 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. Synonymous variant affecting the same amino acid position (i.e. P679P) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NRXN1 NM_001330078.2 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.69
• 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: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.19).
• BP7: Synonymous conserved (PhyloP=2.69 with no splicing effect.

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.2037G>T	p.Pro679Pro	synonymous	Exon 10 of 23	NP_001317007.1
	NRXN1	NM_001135659.3		c.2157G>T	p.Pro719Pro	synonymous	Exon 11 of 24	NP_001129131.1
	NRXN1	NM_001330093.2		c.2034G>T	p.Pro678Pro	synonymous	Exon 10 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.2037G>T	p.Pro679Pro	synonymous	Exon 10 of 23	ENSP00000385017.2
	NRXN1	ENST00000404971.5	TSL:1	c.2157G>T	p.Pro719Pro	synonymous	Exon 11 of 24	ENSP00000385142.1
	NRXN1	ENST00000625672.2	TSL:1	c.2013G>T	p.Pro671Pro	synonymous	Exon 8 of 21	ENSP00000485887.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461696 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727128

⚠️ 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: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111858

Other (OTH) AF: 0.00 AC: 0 AN: 60374

⚠️ 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
BayesDel_noAF	Benign	-0.19
CADD	Benign	10
DANN	Benign	0.69
PhyloP100		2.7
Mutation Taster		=99/1	polymorphism

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: rs199714221; hg19: chr2-50765497;